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SIWES TECHNICAL REPORT
Technical Report · March 2017
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SIWES TECHNICAL REPORT
A TECHNICAL REPORT ON
STUDENT INDUSTRIAL WORK EXPERIENCE
SCHEME (S.I.W.E.S)
UNDERTAKING AT
AUTOGENIUS ROYAL MOTORS
URUBI DIVISION, BENIN CITY.
BY
AIYEKI ADOLOR DAVID
ENG1203259
DEPARTMENT OF MECHANICAL ENGINEERING
FACULTY OF ENGINEERING
UNIVERSITY OF BENIN
SUBMITTED IN PARTIAL FULFILMENT OF THE AWARD OF
BACHELOR OF ENGINEERING (B.ENG) IN
MECHANICAL ENGINEERING
FROM
APRIL 2016 TO SEPTEMBER 2016
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SIWES TECHNICAL REPORT
ABSTRACT
This Industrial training report presents the experience garnered during my 6 months of industrial training
undertaken at Autogenius Royal Motors, Urubi division, Benin City.
My training was on the diagnosis, repairs, programming and maintenance of automobile vehicles
ranging from SUVs, sedan, coupe, wagon, hybrid/electric and light trucks.
During this period, I acquired practical knowledge on how to diagnose, repair, replace and install some
mechanical parts and systems and I also assisted in providing the units the functionality they need.
This report discusses the technical skills gained during the training period and justifying the relevance of
the scheme in equipping students with needed technical competence to thrive in the real world.
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SIWES TECHNICAL REPORT
ACKNOWLEGDEMENTS
My appreciation goes to God almighty, through the help of the Holy Spirit made me to choose
mechanical engineering as my discipline.
To paraphrase an actor who just won an Emmy, “there are so many people to thank”. However, I will
like to thank the Industrial Training Fund for their foresight in putting this program to place and also to
the Mechanical Engineering department, University of Benin, for providing the platform on which was
engaged in the training.
I want to say a big thank you to my industrial based supervisor, Mr. Ogieva Kingsley for his vital
encouragement, support and guidance in my learning process throughout training period at here, and for
giving me the opportunity to experience and undergo training in this company and the technician in my
unit, Mr. Oscar, Mr. Kadiri, Mr. John, Mr. Owen, and Mr. Blessing who helped with solutions to my
numerous questions.
I am grateful to Autogenius Royal Motors for providing with the opportunity to be exposed to
engineering services in the automobile industry.
I want to thank my mother for the encouragement she gave me throughout the Industrial Training period
and also my friends, Friday, for accommodating me in his place during this period, Maureen, Festus and
Ebuka, for their financial support.
Finally, to my Institution based supervisor Engr. Nwunna I.B for his advice and support, to my other
friends and colleague like Osazuwa, Lucky and Shegun Obadina. I say thank you all. Am highly
grateful.
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TABLE OF CONTENT
Title
Page
Abstract………………………………………………………………………………….1
Acknowledgements……………………………………………………………………...2
Table of Content…………………………………………………………………………3-5
List of tables……………………………………………………………………………..5
List of Figures…………………………………………………………….......................5-6
Chapter 1
Introduction to Training program
1.1
Purpose of Training………………………………………………………………7
1.2
Company’s Profile…….....….……………………................................................7
1.3
The Establishment’s Cooperate Goal...…………………………………………...8
1.4
The Establishment’s Scope of Work……………………………………………...8
1.5
Organizational Structure………………………………………………………….9
1.6
Work Flow in the Service Station………………………………………………...10
Chapter 2
The Training Program
2.0
Description of Work done………………………………………………………..11
2.1
Automotive Mechanical System…………………………………………………11
2.2
Engine…………………………………………………………………………….11
2.3
Lubrication System……………………………………………………………….14
2.4
Cooling System……………………………..……………………………………14
2.5
Transmission………………………,………,…………………………………….16
2.6
Braking System……………………………,,…………………………..…………17
2.7
Fuel System…………………………………,,……………………………………18
2.8
Suspension System…………………….………………………………………….,19
2.9
Steering System…………………………..……………………………………......21
Chapter 3
Repair and Maintenance Processes
3.0
Safety Measures and Information………………………………………………….23
3.1
Tools Required…………….………………………………………………………24
3.2
Trouble Shooting Engine…….……………………………………………………25
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3.3
Emission System………………………………………………………………….27
3.4
Engine Cooling System……………………………………………………….......28
3.5
Exhaust System………………………………………………………………........29
3.6
Filters and Fluid……………………………………………………………………30
3.7
Brake Problems……………………………………………………………….........32
3.8
Suspension Issues………………………………………………………………….34
3.9
Ride Control Module………………………………………………………………35
3.10
Transmission problems…………………………………………………………….38
3.11
Sensors…………………………………………………………………………….40
3.12
Spark Plugs………………………………………………………………………..45
3.13
Fuel Injector……………………………………………………………………….46
3.14
Cylinder Head Gasket……………………………………………………………..48
3.15
Hybrid Electric Vehicles………………………………………………………….48
3.16
Six Step Approach…………………………………………………………………49
Chapter 4
On-Board Diagnostics (OBD) System
4.1 What is OBD?............................................................................................................71
4.2 OBD-II Codes Explained…………………………………………………………...73
4.3 Launch X431 IV Scanner…………………………………………………………...74
Chapter 5
Observations and Contributions
5.0
Observations……………………………………………………………………75
5.1
Contributions…………………………………………………………………....75
Chapter 6
Conclusion and Recommendation
6.0
Conclusion…………………………………………………………………….76
6.1
Recommendation………………………………………………………………76
6.2
Challenges encountered during training period……………………………….76
References…………………………………………………………………………….77
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LIST OF TABLE
Table 1:
Injector Problems
LIST OF FIGURES
Figure 1.0:
Organization Structure
Figure 1.1:
Service Work Flow
Figure 2.0:
Mounting a new Engine
Figure 2.1:
Four Stroke Cylinder
Figure 2.2:
Typical cylinder arrangement
Figure 2.3:
Lubricating system
Figure 2.4:
Cooling system
Figure 2.5:
Transmission system
Figure 2.6:
Brake system
Figure 2.7:
Fuel System
Figure 2.8.0: Suspension system
Figure 2.8.1:
Shock Absorber;
Figure 2.8.2:
Ball Joint
Figure 2.8.3:
Stabilizer Bar
Figure 2.9:
Steering system
Figure 2.10:
Rack pinion system
Figure 3.1:
Safety Equipment
Figure 3.2:
Tools required
Figure 3.3.0:
Engine Belt System
Figure 3.3.1:
Hose
Figure 3.4:
Emission System
Figure 3.5:
Exhaust System
Figure 3.6:
Oxygen Sensor
Figure 3.7.1:
Oil Filter
Figure 3.7.2:
Air Filter
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Figure 3.7.3:
Transmission Filter and Paper Gasket
Figure 3.8:
Anti-Lock Brake System (ABS)
Figure 3.9:
Stabilizer Bar Bushings
Figure 3.10:
Suspension Spring
Figure 3.11:
Air Spring
Figure 3.12:
Valve Body
Figure 3.13.0:
Speed Sensor
Figure 3.13.1:
MAF Sensor
Figure 3.13.2:
VSS Sensor
Figure 3.13.3:
Evaporator Sensor
Figure 3.13.4:
Oil Pressure Sensor
Figure 3.13.5:
Throttle Body Temperature Sensor
Figure 3.13.6:
Spark Plug
Figure 3.14:
Injector
Figure 3.15:
Hybrid Electric Vehicle Schematic
Figure 3.16:
Hybrid Battery Pack
Figure 3.17:
Hybrid Pair Change
Figure 4.1:
OBD-II
Figure 4.2:
Launch Scanner
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CHAPTER
1.1
1
INTRODUCTION TO TRAINING PROGRAM
PURPOSE OF TRAINING
The Student Industrial Work Experience Scheme (SIWES) was initiated in 1973 by the Industrial
Training Fund (ITF). This was to update practical knowledge of students in the Universities,
Polytechnics and Colleges of Technology. It was aimed at bridging the gap between the theoretical
knowledge acquired in classes and technical knowledge in the industry by providing students with the
opportunities to apply their educational knowledge in real work situations.
Over the years, SIWES has contributed immensely to building the common pool of technical and allied
skills available in the Nigeria economy which are needed for the nation’s industrial development.
Furthermore, the place and relevance of SIWES is underscored by the fact that the scheme contributes to
improving the quality of technical skills generally available in the pool from which employers source
technical manpower
Its gives student the opportunity to blend the theoretical knowledge acquired in the classroom and with
practical hands on application of knowledge required to perform work in the industry. Also it prepares
students for employment and makes the transition from school to the industry easier after graduation.
I undertook my SIWES at AUTOGENIUS ROYAL MOTORS which is located at 56 Urubi, behind
Okada house, Benin City from APRIL to SEPTEMBER 2015.
1.2
COMPANY’S PROFILE
Autogenius Royal Motors located at 56, Urubi road, behind Okada house, Benin City is an indigenous
establishment that deals with passenger and light goods vehicles such as SUVs, wagon, van, sedan,
coupe, truck, hybrid and pick-up of various brands and models. Though not equipped with the latest
technology available in developed parts of the world, however with its equipment and tools it has been
carrying out proper diagnosis, servicing and maintenance of customer’s vehicle.
The establishment was founded in 2004 by its current Chairman/CEO (Mr. Ogieva Kingsley) it has a
staff strength of approximately 15. Some of its trained personnel have gone to establish their own
mechanical firm.
The organization is mostly known for their computerized approach to diagnosing various automatic cars
ranging from 1995 till date, Engine Control Unit (ECU) and Powertrain Control Module (PCM, usually
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SIWES TECHNICAL REPORT
called the ‘brainbox’) tuning and programming. They also do key programming and alarm installation
on vehicles as well as Transmission Control Module (TCM)
1.3 ESTABLISMENT’S CORPORATE GOAL
Autogenius Royal Motors goal to our clients is to fix your vehicle to the proper working condition in a
clean and professional environment, so that you are happy and satisfied with the service that was
performed.
We also want you to have the trust and confidence in us that you are being treated honestly and fairly.
Also to have the freedom to approach us at any time with any questions or concerns with the service that
you are receiving.
The goal to my employees is to provide them with the best working conditions possible with the proper
tools and equipment to repair our client’s vehicles. This in turn gives them the privilege to associate with
happy, satisfied and dedicated clients. Also, for the trainee to have the freedom to input on how to better
improve the working conditions to offer better service to our clients.
1.4 THE ESTABLISHMENT SCOPE OF WORK
In the area of specialization, Autogenius Royal Motors has the capacity of providing the following
services
1.
2.
3.
4.
Diagnosis
Auto Repair
Service and Maintenance
Key Programming and other programming
Autogenius Royal Motors is made up of two (3) major departments/units,
1. Repair, Servicing and Maintenance Department
2. Diagnosis and Programming Department
3. Air Conditioning and Electrical Department
About Repair, Servicing and Maintenance department: This unit is trusted with the overall
responsibility of caring out all actions which have the objective of retaining or restoring an item in or to
a state in which it can perform its required function. The actions include the combination of all technical
and corresponding administrative, managerial, and supervision actions. It also includes performing
routine actions which keep the device in working order (known as scheduled maintenance) or prevent
trouble from arising (preventive maintenance).
About Diagnosis and Programming Department: This unit carry out On-Board Diagnosis
test, the first step to diagnosing modern automobiles troubles, using an OBD-II scan tool to get the fault
codes or Diagnostic Trouble Codes (DTC). Reprogramming and flashing of the Engine Control Unit
(ECU) as well as erasing false DTCs.
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About Air Conditioning and Electrical Department: This unit deals with the installation,
maintenance and servicing the systems that controls air quality, temperature, humidity inside the car as
well as all electrical work in the car.
1.5 ORGANIZATION STRUCTURE
CHAIRMAN/CEO
Director
Maintenance &
Servicing
Director
Air Conditioning
Director Diagnosis
& programming
Chief Mechanic
Chief Electrician
Senior Technician
Chief Diagnostic
Technician
Chief Programmer
Senior Mechanic
Senior Electrician
Junior Technician
Senior Diagnostic
Technicians
Senior Programmer
Junior Mechanic
Junior Electrician
Junior Diagnostic
Technician
Junior Programmer
Fig. 1.0
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1.6
WORK FLOW IN THE SERVICE SECTION
Diagnostic
Customers
technician
Service
Service
Adviser
adviser
(Warehouse)
Workshop
technician
fig. 1.1
Some of Autogenius Royal Motors Corporate customers include,
Private Individuals
Nigeria Police Force
Transport lines
Other institutions.
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2.0
CHAPTER 2
THE TRAINING PROGRAM
DESCRIPTION OF WORKDONE
During my stay in Autogenius Royal Motors, I was assigned to the service and maintenance department
as a Diagnosis/Mechanical Technician. though I had the privilege to learn from the first two
departments. Job duties in the department includes:
Keep equipment available for use, inspecting and testing vehicles, completing preventive maintenance
such as engine tune-ups, oil changes, replacing filters, diagnosing and scanning of automatic vehicles.
Maintain vehicle functional condition by listening to operator complaints; conducting inspections,
repairing engine failures, dropping engines and mounting new ones, dropping gearbox and mounting
new ones, repairing mechanical systems malfunctions; replacing parts and components. Verifies vehicle
serviceability by conducting, test drives; adjusting controls and systems.
2.1
2.2
AUTOMOTIVE MECHANICAL SYSTEMS
ENGINE
Internal combustion gasoline engines run on a mixture of gasoline and air. The ideal mixture is 14.7
parts of air to one part of gasoline (by weight.) Since gas weighs much more than air, we are talking
about a whole lot of air and a tiny bit of gas. One part of gas that is completely vaporized into 14.7
parts of air can produce tremendous power when ignited inside an engine.
Fig. 2.0
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Let's see how the modern engine uses that energy to make the wheels turn.
Air enters the engine through the air cleaner and proceeds to the throttle plate. You control the amount
of air that passes through the throttle plate and into the engine with the gas pedal. It is then distributed
through a series of passages called the intake manifold, to each cylinder. At some point after the air
cleaner, depending on the engine, fuel is added to the air-stream by either a fuel injection system or, in
older vehicles, by the carburetor.
Once the fuel is vaporized into the air stream, the mixture is drawn into each cylinder as that cylinder
begins its intake stroke. When the piston reaches the bottom of the cylinder, the intake valve closes and
the piston begins moving up in the cylinder compressing the charge. When the piston reaches the top,
the spark plug ignites the fuel-air mixture causing a powerful expansion of the gas, which pushes the
piston back down with great force against the crankshaft, just like a bicycle rider pushing against the
pedals to make the bike go. Finally, during the exhaust stroke, where the piston is at the bottom of the
cylinder the exhaust valve opens to allow the burned gas to be expelled to the exhaust system.
Fig. 2.1
Engine Types
The majority of engines in motor vehicles today are four stroke, spark ignition, internal combustion
engines and diesel engines.
Diesel engines present two main advantages over their gasoline powered counterparts, an increase in
maximum and low-end torque for heavy duty vehicles and increased fuel efficiency. The benefits of
increased torque typically apply to truck buyers seeking maximum towing and hauling capacity.
A hindrance in the widespread adoption of diesel engines in passenger cars are the high emission levels.
Two ways manufacturers are combating the high emissions of diesel engines is by equipping diesel
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SIWES TECHNICAL REPORT
particulate filters within a vehicles exhaust and incorporating exhaust treatment fluids which break down
damaging particulates before they are released.
There are several engine types which are identified by the
number of cylinders and the way the cylinders are laid.
Straight line cylinders have their cylinders in row while the
“V” arrangement uses two banks of cylinders side-by-side and
its commonly used in V-6, V-8 configurations
Fig 2.2
Some automobile engine parts include;
Spark plug
The spark plug supplies the spark that ignites the air/fuel mixture so that combustion can occur. The
spark must happen at just the right moment for this to work properly
Valves
The intake and exhaust valves open at the proper time to let in air and fuel and to let out exhaust.
Piston
Piston is a cylindrical piece of metal that moves up and down inside the cylinder.
Piston rings
Piston rings provide a sliding seal between the outer edge of the piston and the inner edge of the
cylinder, the rings serves two purposes.
 They prevent the fuel/air mixture and the exhaust in the chamber from leaking into the sump
during compression and combustion,
 They keep oil in the sump from leaking into the combustion area where it would be burn and
lost.
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Connecting rod
The connecting rod connects the piston to the crankshaft, it rotates at both ends so that its angle can
change as the piston moves and the crankshaft rotates.
Crankshaft
The crankshaft turns the piston’s reciprocating motion in the cylinder into circular motion.
Sump (oil pan)
The sump surrounds the crankshaft. It contains some amount of oil, which collects in the bottom of the
sump.
Camshaft
The camshaft in an internal combustion engine makes it possible for the engine’s valve to open and
close, the asymmetrical lobes of the camshaft correspond to the engine valves
2.3 LUBRICATING SYSTEM
Oil is the life-blood of the engine. An engine running without oil will last about as long as human
without blood. Oil is pumped to all the moving parts of the engine by and oil pump. The oil pump is
mounted at the bottom of the engine in the oil pan and is connected by a gear to either the crankshaft or
camshaft. This way, when the engine is running the pump is pumping simultaneously. There is usually
an oil pressure sensor near the oil pump that monitors pressure and sends this information to a warning
light on the dash board (this features is found in modern cars as it might be in your car), when the
ignition key is turned on, but before the car is started the oil light should light, indicating that there is no
oil pressure yet, but also letting you know that the warning system is working.
fig. 2.3
2.4 COOLING SYSTEM
A car engine produces enormous amount of heat when it is running, and must be cooled continuously to
avoid engine damage, generally this is done by circulating coolant liquid usually water mixed with an
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SIWES TECHNICAL REPORT
antifreeze solution through special passages.
Fig. 2.4
How the cooling system work?
Actually there are two types of cooling system found on motor vehicles: liquid cooled and air cooled.
Air cooled engines are found on a few older cars, but for most part, automobiles and trucks use liquid
cooling systems and that is what this write up will concentrate on subsequently.
The cooling system is made up of the passages inside the engine block and heads, water pump to
circulate the coolant, a thermostat to control the temperature of the coolant, a radiator cap to control the
pressure inside the system, and a plumbing consisting of interconnecting hoses to transfer the coolant
from the engine to the radiator and also to the car’s heater system where hot coolant is used to warm up
the vehicle’s interior on a cold day.
A cooling system works by sending a liquid coolant through passages in the engine block and heads. As
the coolant flows through these passages, it picks up the heated fluid then makes its way through a
rubber hose to the radiator in the front of the car. As it flows through the thin tubes in the radiator, the
hot liquid is cooled by the air stream entering the engine compartment from the grill in front of the car.
Once the fluid is cooled, it returns to the engine to absorb more heat. The water pump has the job of
keeping the fluid moving through this system of plumbing and hidden passages. In order to prevent the
coolant from boiling, the cooling system is designed to be pressurized, under pressure the boiling point
of coolant is raised considerably. However, too much pressure will cause hose and other parts to burst,
so a system is needed to relieve pressure if it exceeds a certain point and this is job of radiator cap.
2.5 TRANSMISSION SYSTEM
A car transmission is simply the assembly of parts, including the gears and the propeller shaft that
transmit the power from the engine to the axle.
There are two kinds of transmission: Automatic and Manual Transmission
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SIWES TECHNICAL REPORT
Fig 2.5
Main components of a transmission are:
Transmission Control Modules: one of the main part of a transmission is transmission control
modules, it controls the automatic transmissions, but is nonexistent in manual transmissions.
Transmission Filters: Another important component of transmissions is filters. Transmission depend on
transmission fluid coolant that allows the clutch to engage and disengage, gears to change, valves to
open and close, and so on. The filter that any outside particles or substances are not mixed in with the
fluid. The swamp has magnets in it that helps to attract any iron fillings resulting from the gear
engagements, thus preventing them from going into the gearbox
Transmission shafts: transmissions are also connected to the engine crankshaft by means of a flywheel,
since the combustion engine inside the transmission cannot go below a particular speed. Therefore, the
output of the transmission is done via the driveshaft, hence the name drive wheels of a car.
Manual Vs Automatic Transmission
Manual transmissions typically run longer and are cheaper to fix and repair when compared to automatic
transmissions. Nonetheless, many people still prefer automatic transmission because of their ease of use.
Manual transmissions are more affordable and more traditional as well. We’ll dive into the various
factors with the cost of repairing or replacing a transmission later, as well as many problems that can
result, which will require you to repair or replace them. After all, transmissions are not everlasting and
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SIWES TECHNICAL REPORT
like any part of the car, they need fixing on time or another and it’s better to do it when you know
approximately what is required and how much it will cost you.
2.6 BRAKING SYSTEM
An automatic braking system is a group of mechanical, electronic and hydraulic activated components
which use friction/heat to stop a moving vehicle.
How the automotive Braking System works?
When the brake pedal is depressed the pressure on the brake pedal moves a piston in the master cylinder,
forcing the brake fluid from the master cylinder through the brake lines and flexible hoses to the calipers
and wheel cylinders. The force applied to the brake pedal produces a proportional force on each of the
pistons.
The calipers and wheel cylinders contain pistons, which are connected to a disc brake pad or brake shoe.
Each output piston pushes the attached friction material against the surface of the rotor or wall of the
brake drum, thus slowing down the rotation of the wheel. When the pressure on the pedal is released, the
pads and shoes return to their release positions. This action forces the brake fluid back through the
flexible hose and tubing to the master cylinder.
Component of Automotive Braking System:
Brake Assembly: brake assembly is comprised of a disc or rotor, a caliper assembly, disc brake
pads and the wheel bearings and hardware necessary to mount the components on the here it is
created through hydraulic lines to the vehicle. The caliper is connected to the master cylinder
through tubes, hoses and valves that conduct brake fluid through the system.
Brake Drum: brake drums are comprised of a drum and backing plate, a hub or axle assembly,
brake shoes, wheel cylinder, wheel bearings and hardware necessary to mount these components
on the vehicle. The wheel cylinder is connected to the master cylinder through tubes, hoses and
valves that conduct brake fluid through the system.
Brake Fluid: Brake fluid is a type of hydraulic fluid used in brake applications for automobiles
and light trucks. It is used to transfer force under pressure from where it is created through
hydraulic lines to the braking mechanism near the wheels. Braking applications produce a lot of
heat so brake fluid must have a high boiling point to remain effective and must not freeze under
operating conditions.
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SIWES TECHNICAL REPORT
Fig. 2.6
2.7
FUEL SYSTEM
The fuel system is critical in storing and delivering the gasoline or diesel fuel your engine needs to run.
Think of it as your vascular system, with a heart (fuel pump), veins (fuel lines) and kidneys (filter). A
failure in any of these fuel system component has the same devastating effects as in your body.
Component of the fuel system
Fuel tank: basically a holding tank for your fuel. When you fill up at a gas station the gas travels down
the filter tube and into the tank. In the tank there is a sending unit which tells the gas gauge how much
gas is in the tank. Some fuel thank houses the fuel pump and has more emissions controls to prevent
vapors leaking into the gas.
Fuel pump: on newer cars the fuel pump is usually installed in the fuel tank. Older cars have the fuel
pump attached to the engine or on the frame rail between the tank and the engine. If the pump is in the
tank or the frame rail, then it is electric and is driven by your car battery. Fuel pumps mounted to the
engine use the motion of the engine to pump the fuel, most often being driven by the camshaft, but
sometimes the crankshaft.
Fuel filter: clean fuel is critical to engine life and performance. Fuel injectors and carburetors have tiny
openings which clog easily so filtering the fuel is a necessity. Filters can be before or after the fuel
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SIWES TECHNICAL REPORT
pump. They are most often made from a paper element, but can be stainless steel or synthetic material
and are designed to be disposable in most cases. Some performance fuel filters will have washable mesh,
which eliminated the need for replacement.
2.8
Fig. 2.7
SUSPENSION SYSTEM
Fig 2.8.0
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SIWES TECHNICAL REPORT
Suspension is the term given to the system of shock absorbers and linkages that connect a car to its
wheels. The suspension system has two basic functions:
1. to keep the car’s wheels in firm contact with the road to provide the traction and
2. to provide a comfortable ride for the passengers and isolate them from road noise, bumps and
vibrations.
Component of the suspension system
The basic components of a suspension system are as follows:
Control Arms and Bushing: holds the steering knuckle, bearing support, or axle housing in
position, as the wheel moves up and down. The outer end of the control arm has a ball joint and
inner end has bushings. Vehicles, having control arm on the rear suspensions may have bushings at
both ends. The control arm bushing act as bearings, which allows the control arm to move up and
down the shaft bolted to the frame or suspension unit.
Shock Absorbers and Struts: shock absorbers are necessary because springs do not settle down fast
enough. After the spring has been compressed and released. It continues to shorten and lengthen for
a time, such spring action on a vehicle would produce a very bumpy and uncomfortable ride. It
would also be dangerous because a bouncing wheel makes the vehicle
fig. 2.8.1
difficult to control, therefore a dampening device is needed to control the spring.
Ball Joints:
Fig. 2.8.2
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The ball joints are connections that allow limited rotation in every direction and support the weight of
the vehicle. They are used at the outer ends of the control arm where arms attach to the steering knuckle.
In operation, the swiveling action of the ball joints allows the wheel and steering knuckle to be turned
left or right and to move up and down with changes in road surface.
Strut Rods: the strut road fastens to the outer end of the lower control arm and to the frame. This
prevents the control arm form swinging toward the rear or front of the vehicle. The front of the strut
rod has rubber bushings that soften the action of the strut rod. These bushings allow a controlled
amount of lower control arm movement while allowing suspension to travel.
Stabilizer bar: limits body roll of the vehicle during maneuvering
Spring: supports the weight of the vehicle, permits the control arm and wheel to move up and down,
also helps in isolation of vibration.
Fig. 2.8.3
2.9
STEERING SYSTEM
Fig. 2.9
Fig 2.10
The direction of motion of a motor vehicle is controlled to a desired direction steering system. When the
driver turns the steering wheel, a shaft from the steering column turns a steering gear. The steering gear
moves tie rods that connect to the front wheels. The tie rods move the front wheels to the vehicle right or
left.
Today, there are two types of steering systems:
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SIWES TECHNICAL REPORT
1. Standard mechanical (reciprocating ball) steering and
2. Rack and pinion steering.
The standard mechanical steering can be either power-assisted or non-power. Rack and pinion is
almost always power assisted, although there are cases where it is not.
Standard mechanical (reciprocating ball) steering: The steering wheel is connected to the steering
box through the steering column. The steering box turns the rotation of the steering wheel 90o and, in the
case of power steering, uses high-pressure fluid to help actuate the steering. The steering box has an arm
attached to the output shaft called the pitman arm. This connects the steering to the steering gear. The
pitman arm is connected to one end of the center link (drag link). On the other end of the center link is
an idler arm. Between the idler and pitman arms, the drag link is supported in the proper position to keep
the left and right wheels working together. The inner tie rod ends are attached to each end of the center
link and provide points for the steering gear. From there it goes to the outer tie rod ends through an
adjustment sleeve. This sleeve joins the inner and outer tie rod ends together and allows for adjustment
when the front wheels are aligned. The outer tie rods ends are connected to the steering knuckle that
actually turns the front wheels. The steering knuckle has an upper and lower ball joint on which it pivots
and creates the geometry of the steering axis.
Rack and pinion steering: Rack and pinion steering, on the other hand, basically combines the steering
box and drag link into one unit. The steering wheel, through the steering column, is directly connected to
the track. Inside the steering rack is a pinion assembly that moves a toothed piston which in turn moves
the steering gear. One end of the inner tie rod ends is connected to each of this piston and the other end
is connected directly to the outer toe rod end. The inner tie rod end is actually threaded into the outer tie
rod end and can be rotated to make adjustments during a wheel alignment. The advantage of rack and
pinion steering is that it’s more precise than mechanical system. By reducing the number of parts and
pivot points, it can more accurately control wheel direction, making the steering move responsive. The
disadvantage of a rack and pinion steering system is that it’s prone to leakage, requiring replacement of
the steering rack assembly.
Components of steering system
Power Steering fluid reservoir
Power Steering Pump
Rack and Pinion steering gear
Steering Wheel
Pitman Arm
Steering Box
Tie rod/Track rod
Steering Column and Knuckle
Drag Link
Steering Shaft
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CHAPTER 3
Repair and Maintenance Process
Mechanical systems in automobiles are a little complex and some problems may need to be serviced at
the repair shop.
3.0 SAFETY INFORMATION
Most accidents in servicing/mechanical repair involve slips, trips and falls or poor manual handling.
Other causes of incidents sometimes resulting in serious injury or death include working under
inadequately supported vehicles, bridging the car battery with a spanner, incidents involving petrol
and vehicle movement.
Keeping work areas free of clutter is an important, but often overlooked, step in running a safe and
productive workshop. Requiring appropriate protective gear minimizes eye and finger lacerations, which
are common auto body shop injuries. Shops should purchase appropriate overall, safety boot, eyewear,
and make protective gloves available to prevent cuts from glass, sheet metal or other jagged objects.
Fig. 3.1
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3.1 TOOLS REQUIRED
Fig. 3.2
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3.2 TROUBLESHOOTING ENGINES
BELTS AND HOSES
Belts and hoses are essential to the cooling, air conditioning and charging systems, and the engine.
Don’t take these routine replacement intervals for granted because they can break down and leave you
stranded.
BELTS:
Fig. 3.3.0
The timing belt is a notched rubber belt, sometimes called a Gilmer belt. This belt allows the crankshaft
to drive the camshaft, which in turn opens and closes the valves. Without this belt, the engine can't run.
How do I know it's time to replace my timing belt?
A loose or worn belt will cause ticking or rattling noises, poor engine performance and overheating,
usually triggering the check engine light. If the timing belt breaks, the engine can't run -- and on some
engines that break can cause internal damage. Most engines have timing chains, which typically don't
require replacing.
How often should I replace my timing belt?
The schedule for replacing a timing belt varies by manufacturer, with some saying it should be every
60,000 miles and others 100,000 miles or more. Changing the timing belt requires removing many other
parts, adding to labor costs. If the timing belt drives the water pump, many mechanics recommend
replacing the pump at the same time.
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HOSE:
Fig. 3.3.1
Your engine needs coolant, the power steering rack needs fluid, and the calipers need fluid to squeeze
the rotors to stop the car. Most fluids make their way to their destination through hoses. Those hoses are
generally made of rubber and they wear out over time. Different types of hoses are subject to different
amounts of wear and tear, and therefore have different life spans.
How often should hoses be replaced?
Most automakers and belt manufacturers recommend having your hoses replaced once every 4 years or
so. Of course, this will vary with mileage – a car that’s heavily driven may need to have the hoses
replaced much sooner.
How to tell if your hoses need to be replaced
There are several key things to look for, including kinks, stiff or brittle texture, surface cracks, and
bulges or bubbles.
Inspect the hoses and note any kinks or obvious signs of wear. Squeeze the radiator hoses (when cool
ONLY) and see how they feel. If hoses are soft and pliable, there is no need to replace them. However,
if hoses feel stiff, crackly, or brittle, they need to be replaced.
While squeezing the hoses, inspect the surface for small cracks. These can easily become big problems,
as they’re the primary point for a “blown” hose. You can also check where the hoses connect to the inlet
or outlet pipe. Look for bulges or bubbles around the hose clamps, as this is a sign of impending failure.
Hoses can last a long time, but replacing them before they fail is always the better option, as it could
prevent you from being stranded on the side of the road waiting for help to arrive.
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3.3
EMISSION SYSTEM
Fig. 3.4
Car emission system keeps the engine running cleanly and efficiently in all sorts of operating conditions.
A steady or flashing warning light on your vehicle dashboard indicates a problem that is currently
happening and may require immediate attention. Failure to do so can reduce your gas mileage or cause
your vehicle to pollute.
What does it do?
Emission system controls the emissions, exhaust and pollutants (including gasoline vapors escaping
from the fuel tank), using an array of sensors, computerized engine controls and the exhaust
components. The emission system substantially reduces harmful gases such as carbon monoxide (CO),
unburnt hydrocarbons (HC) and oxides of nitrogen (NOx) and, by law, must be maintained in operating
condition.
Some factors affecting the emission system include:
Driving and atmospheric conditions, Mileage, Vehicle age, Type of spark plug electrode material, Poor
vehicle maintenance, Poor quality fuel, Damaged or worn sensors, Dry-rotted or cracked vacuum hoses
To make sure that the Emission System on your vehicle is working properly.
1. Use the proper fuel for your vehicle.
2. Do not let your vehicle run out of fuel.
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3. Do not turn the vehicle off while in motion.
4. Make sure the components are maintained and serviced when they need to be.
3.4
ENGINE COOLING SYSTEM
The engine cooling system affects your car’s overall dependability and engine longevity. Cooling
systems have advanced over the years with new coolant formulations and new radiator designs and
materials. If you suspect a problem with your cooling system, you should check it immediately.
What does it do?
The key parts of the cooling system remove heat from the engine and automatic transmission and
dissipate heat to the air outside. The water pump circulates coolant through the engine. The coolant
absorbs heat and returns it to the radiator where heat is dissipated. The thermostat regulates the coolant
temperature to keep it consistent for efficient engine operation.
Factors that affect the replacement of cooling system parts include:
Driving habits, Operating conditions, Type of vehicle, Type of coolant, Frequency of regular
maintenance such as coolant changes
Symptoms:
Overheating, Sweet smell, Leaks, repeatedly need to add fluid
FIXING SOME ENGINE COOLING SYSTEM PROBLEMS:
If steam is pouring from under your hood, a temperature warning light is glowing bright red on your
dashboard or the needle in the temperature gauge is cozying up to the High mark, it's time to pull off the
road and shut down the engine before it fries from overheating.
Any indication of overheating is a serious matter, so the best course of action is to shut down the engine
to prevent further damage. Driving a car with an overheated engine can warp cylinder heads and damage
internal engine parts such as valves, camshafts and pistons.
Even letting the engine cool for an hour and topping off the radiator with a 50-50 mix of antifreeze and
water may not fix what's wrong. Here are some reasons an engine will overheat:
The coolant level could be extremely low, because of long-term neglect or because a leak has
developed in the radiator or radiator hoses. Coolant circulates inside the engine block to cool it,
and the leak might be in the block, or from the water pump or heater hoses. Old coolant loses its
corrosion-inhibiting properties, allowing rust to form and ultimately causing damage.
The thermostat that allows coolant to circulate may be stuck in the closed position or a clog may
have developed, perhaps from debris in the cooling system.
The engine cooling fan has stopped working or the radiator's cooling fins are clogged with debris
so that the air flow that reduces the coolant temperature is restricted.
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The radiator cap has gone bad and no longer maintains enough pressure in the cooling system,
allowing coolant to boil over (engines normally operate at about 210 to 220 degrees Fahrenheit).
The head gasket that seals the gap between the cylinder head and engine block may have failed,
allowing coolant to leak inside the combustion chambers. The steam should be visible coming
out of the exhaust system.
The water pump has stopped working or the belt that drives it broke or is slipping and not
pumping enough coolant.
You've been towing a 5,000-pound trailer with a vehicle equipped to tow only 2,000 pounds,
exceeding the vehicle's cooling capacity. (You probably also strained the transmission.)
Checking your engine coolant level in the overflow tank on a regular basis can help avoid disasters. If
you have to keep topping off the coolant, that's an indication of a small leak that should be taken care of
before it becomes a major one. Having your coolant tested and the entire system inspected by a
mechanic every couple of years is an even better way to prevent cooling system disasters.
3.5
EXHAUST SYSTEM
Fig. 3.5
Exhaust system has come a long way from the old days of exhaust pipes and mufflers. Today, the
exhaust system is safety and emissions control rolled into one. Have your car’s exhaust system inspected
regularly and check it immediately if you suspect any problems.
The exhaust fumes travel through an exhaust pipe/tube, which carries them through the catalytic
converter, right through the muffler, and out the exhaust tip. Along the exhaust pipe are oxygen sensors
so that they can keep track of the emission levels.
The Exhaust Gas Recirculation (EGR) Valve is responsible for single-handily bringing down the amount
of exhaust emissions your car expels from the tailpipe into the atmosphere. The valve makes it possible
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to recirculate the engine gasses by putting them back into the intake manifold. At this point the engine
burns them again, so there are no emissions to worry about.
The catalytic converter converts pollutants in the exhaust system into less toxic pollutants by using a
redox reduction method.
The exhaust system routes dangerous exhaust gas from the engine out and away from the car to keep
from affecting the occupants. Next, the exhaust system reduces exhaust noise from the engine. The
catalytic converter reduces the level of harmful pollutants in the exhaust. The oxygen sensors mounted
in the exhaust system monitor the level of oxygen in the exhaust gases to maintain efficient engine
operation and to monitor the converter’s operation
Symptoms: Loud noise, Rattling noise when starting, accelerating or braking, Drowsiness while
driving, Rotten eggs smell, a sudden loss of power, Poor fuel economy, Vehicle is performing poorly,
such as stalling while driving or a jerking feeling, Misfiring engine, Check Engine Light
OXYGEN SENSOR
Fig. 3.6
The oxygen sensor in your vehicle measures the exhaust gases exiting the engine and this information is
used by the ECU to determine the air to fuel ratio in your engine in real time. The oxygen sensor
transmits the data to the vehicle’s computer to keep the optimal air to fuel to air ratio in your engine.
A bad or failing oxygen sensor will have a bad impact on the environment and poor engine performance,
so there are a few things to watch out for before your oxygen sensor completely fails.
1. Check Engine Light comes on
2. Bad gas mileage
3. Rough engine idle and misfires
3.6
FILTERS AND FLUIDS
Filters are important to the longevity of your car and interior comfort. The oil filter traps contaminants,
allowing the oil to flow through the engine unrestricted. The fuel filter separates harmful contaminants
that may cause problem
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Fig. 3.7.1
fig. 3.7.2
The air filter traps dirt particles, which can cause damage to engine cylinders, walls, pistons and piston
rings. The air filter also plays a role in keeping contaminants off the airflow sensor (in fuel-injected
cars).
The crankcase ventilation system works to relieve any pressure from the engine’s crankcase attributed to
blow by gases by rerouting the gases back into the engine’s intake manifold to be consumed by the
engine. This is necessary, as excessive crankcase pressures can cause oil leaks to form if allowed to
build too high.
The cabin filter helps trap pollen, bacteria and dust that may find their way into a car’s ventilation
system.
The transmission filter is a vital part of that system and is situated above the transmission pan, which
catches any excess fluid, and below a pickup tube that connects to the oil pump, which regulates the
pressure of fluid in the transmission. The transmission filter functions as a sieve to collect contaminants
like dirt and debris before sending lubricating fluid to the transmission itself. the transmission filter and
fluid should be replaced every 25,000 miles.
Fig. 3.7.3
Filters are normal wear items that require regular checks and replacement.
BRAKE FLUID
Water in the brake lines lowers the boiling point of the fluid, so stopping ability can diminish in hard
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stops as heat in the system increases. In addition, over time the moisture can cause internal corrosion in
the brake lines, calipers, the master cylinder and other components.
Flushing and replacing brake fluid might cost less on many vehicles, so clearly there's value in keeping
up with maintenance.
POWER-STEERING FLUID
You should check the power-steering fluid reservoir monthly to make sure it has the proper amount and
that the power-steering system isn't leaking. Reservoirs on many vehicles are the see-through plastic
type, so you don't even have to remove a cap to check the level
TRANSMISSION FLUID
Automatic transmissions are complex and have many moving parts. Today’s vehicles can also be
equipped with a CVT (Constant Variable Transmission), which has even more moving parts and smaller
tolerances. The fluids that are used in these transmissions are designed to handle the high internal
pressures and temperatures without losing their viscosity and lubricating abilities. They also contain
detergents that allows the fluid to pick up debris from within the transmission and carry it to the filter.
As the fluid breaks down from age and everyday driving, it loses its ability to accomplish these tasks
causing the internal clutches and bearings to fail.
Manual transmissions are built much differently than automatic transmissions. Manual transmissions
have a series of internal gears, bearings, and synchronizers that are used to allow the driver to shift
gears. Most manual transmissions use a heavy petroleum-based oil for lubrication. As this oil breaks
down, it loses its lubricating properties which can make it harder for the driver to get the transmission
into gear and can cause bearing failure.
It is important to only use the manufacturer's recommended fluid in your transmission.
3.7 BRAKE PROBLEM
Brake problems usually indicate the need for certain repairs or replacement parts, so here is a quick
review of some common fixes:
DIAGNOSING BRAKE ISSUES:
There are a few warning signs that you should be aware of regarding your vehicle’s brakes. A hard-to
press-pedal, grinding sounds, and vibrations in the pedal are all signs that something isn’t working
properly. You should do the following to identify issues with your brakes:
Testing the parking brake
Testing the deceleration brakes
Visually inspect the disc brakes
Visually inspect the drum brakes
With these methods of checking your brakes, you’ll be able to inspect most of the components of the
braking system. Keep in mind that small squeaks can be caused by metal rubbing, even if the pads and
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rotors are still in good shape - so if you can’t find the source of the sound, you may just need to get the
brakes lubricated.
BRAKE PAD AND ROTOR PROBLEM:
Subject to tremendous friction and heat, brake pads wear down and must be replaced as part of a car's
regular maintenance. In disc-brake systems, the brake pads are the friction material the caliper squeezes
against the rotating disc, or rotor, to slow the wheel's rotation and stop the car. In drum brakes, the pads
are called shoes.
How do I know when to change my brake pads and rotors?
Squeaks, squeals and metal-to-metal grinding noises are typical signs you're past due for new brake pads
and/or rotors.
How often should I replace my brake pads and rotors?
Brake life depends mainly on the amount and kind of driving you do, such as city versus highway, and
your driving style. Some drivers just use the brakes more than others. For that reason, it's hard to
recommend time or mileage guidelines
ANTI-LOCK BRAKE SYSTEM (ABS)
Fig. 3.8
The
antilock braking system control module is a microprocessor that runs diagnostic checks of a vehicle's
ABS. It processes information from wheel-speed sensors and the hydraulic brake system to determine
when to release braking pressure at a wheel that's about to lock up and start skidding.
Antilock systems prevent skids when braking, and stability control intervenes to prevent skids even
when the brakes aren't applied.
A dashboard ABS warning light is supposed to come on for a few seconds every time a vehicle is
started, but if it comes on while you're driving it signals that the control module has conked out, a wheel
sensor has failed or another problem has developed.
On many vehicles, the brakes should still operate normally when the warning light is on, but the antilock
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function won't work. On some vehicles, though, braking ability will be reduced if the antilock system
malfunctions, and stability control and traction control (on vehicles with those features) might also be
disabled.
How do I know if my ABS system is not working?
A warning light for the ABS is supposed to illuminate briefly every time you start your car. If the
warning light stays on, that means the antilock system has been deactivated because of an electrical or
mechanical malfunction. In addition, if your vehicle has stability control and traction control, those will
be disabled too because they rely on the same wheel-speed sensors as the antilock system.
How often should I replace my ABS control module?
It's the brains of the antilock braking system: a microprocessor that adjusts braking force to individual
wheels to prevent skids based on signals from wheel-speed sensors. It is more likely that a wheel-speed
sensor or other component exposed to the elements will fail before the control module, but as with other
electronic components, it can happen. When it does, the antilock system will be disabled and an ABS
warning light should illuminate.
3.8 SUSPENSION ISSUES
Suspension components, including springs, shock absorbers (or struts on some vehicles), anti-roll bars,
control arms and other parts, are like combat troops serving on the front lines: They take a pounding
daily from pock-marked streets, railroad tracks, rain, snow, road salt, gravel, all manner of dirt and
grime, and the occasional piece of scrap metal or other debris that drivers see too late to avoid.
Under those conditions, just about any suspension component can be damaged or worn out from years of
abuse, resulting in a number of symptoms and/or noises that should be your wakeup call to see a
technician.
HOW TO INSPECT YOUR SUSPENSION SYSTEM?
Many car owners become aware that it is time to investigate their vehicle's suspension components when
their car starts to behave abnormally. This can include such times when strange sounds are heard, like
clanking or knocking when driving over bumps. Constantly correcting the steering wheel to assist the
vehicle going straight is another abnormal experience. These are just two symptoms that lead to a need
for a suspension system inspection.
There are a variety of components that make up the suspension system. Struts, mounts and springs,
control arms and ball joints, just to name a few. Along with suspension parts, many other pieces of the
car affect the suspension system, such as the tires. They all work together in harmony to cushion both
the car and the driver from the rough terrain being driven on. If one part fails, the other components will
fail to do their job properly as well, leading to further damage and needed repairs.
Inspecting the suspension system
Step 1: Take your car for a test drive
Step 2: Inspect the outside of the vehicle
Step 3: Bounce the car.
Step 4: Jack up the car.
Step 5: Shimmy the tire.
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SYMOTOMS OF A BAD OR FAILING HUB ASSEMBLY
The wheel hub assembly includes wheel studs that attach the wheels of the vehicle to the car and is
mounted to the steering and suspension system on the front end and the rear axle on the rear end. In
theory, this single wheel hub assembly should last the lifespan of the vehicle, however, like any other
mechanical device, it is subject to wear and tear and can break or wear out prematurely.
The wheel hub assembly is prone to damage caused by multiple driving situations such as:
Hitting pot holes, striking cubs, being involved in vehicle collisions
Although this part takes a tremendous amount of abuse, it's commonly overlooked when repairs are
done to other mechanical components such as tires and wheels, suspension parts, coils, shocks and struts
and other front end and rear end housing parts. When the part is damaged or is beginning to show signs
of premature wear, it will commonly show some warning signs or symptoms that can be easily
recognized by most car owners.
Listed below are a few of the symptoms that car owners should be aware, that will alert them to a bad or
failing wheel hub assembly:
1.Roaring sound coming from the tire / wheel area
2. Steering wheel vibrates or feels loose
3.Tire / wheel combination has a lot of play when in the air
4. Clicking sound from the wheels
If you notice any of the above warning signs, please contact a local ASE certified mechanic as quickly
as possible so they can diagnose the precise problem and fix your vehicle as quickly as possible.
3.9 RIDE CONTROL MODULE
Most cars use springs and shocks/struts, but some vehicles use an air suspension system. This type was
once reserved primarily for luxury vehicles, but it is becoming more common on mid-range cars today.
An air suspension uses inflatable “bags” of air to provide the right amount of cushion for comfort, and to
adjust the ride height of your vehicle. It’s an automatic system (although some offer manual height
selection capabilities).
While air bag suspensions are durable and long lasting, problems can develop. Air bags can leak, or they
can crack and wear, allowing air to escape. Another potential problem is the failure of the ride control
module. This is a computerized controller that is responsible for adjusting the right height, stiffness and
cushion of your suspension system.
There is no set lifespan for a ride control module. Under ideal conditions, it should last for the life of
your vehicle. However, like all other electronic systems, it is subject to premature failure. When this
happens, you will not be able to change the ride height or other settings for the suspension system. It’s
also possible that the air bags will begin to deflate unevenly, leading to an uneven or jarring ride on the
road.
While driving with a failed ride control module isn’t a huge safety issue, it does reduce your comfort
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and adds wear and tear to other components. Knowing a few signs to watch for that might indicate a
failing or failed ride control module is important:
The vehicle sits unevenly on level ground, the air pump for the suspension system doesn’t turn on (can
indicate a failed pump or a problem with the ride control module), Ride quality is harsher than usual
Ride height is uneven or cannot be changed, Ride Height light is on in the dash
If you’re experiencing any of these problems, or any other issues with your air ride system, your
mechanic can help
CONTROL ARM ASSEMBLY
The control arm assembly keeps the wheels in line with the car’s body to control the motion of the
wheels.
Over time, the control arm assembly can become worn or bent. These assemblies normally wear out
between 90,000 and 100,000 miles.
To keep this assembly lasting longer, have it inspected every time your suspension is looked at. This
way, each component of the control arm assembly is properly assessed by a professional.
Since the control arm assembly will go bad over time, it is important that you can recognize the
symptoms. As soon as you recognize the signs, you can have your vehicle inspected and repaired, which
will be a relatively straightforward process.
Signs your control arm assembly needs to be replaced include: The steering wheel or vehicle vibrates
while you are driving down the road, Loud noises, such as banging, when you go over bumps or
potholes, Uneven tire wear, the steering wheel is not as responsive as it was before, the wheels move or
shake while you are driving
The control arm assembly is an important part of your vehicle and its suspension, as soon as something
is wrong with it, have it replaced right away so you can drive your vehicle safely again
STABILIZER BAR BUSHINGS
Fig. 3.9
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It plays a significant role in handling, particularly around sharp turns. The bar’s job is pretty simple. It is
designed to redistribute the weight of the vehicle to help prevent rollovers, and to enhance handling.
They’re really not much more than rubber dampers, and therein lies their weakness. The underside of
your car is exposed to high heat, freezing temperatures, road salt, water, rocks and a lot more. Over time,
this will degrade the rubber bushings, causing them to shrink and crack. Eventually, they can’t do their
job and you lose some of the benefits of your sway bar (stabilizer bar). You’ll also notice increased road
noise.
Driving with damaged or degraded stabilizer bar bushings can be somewhat dangerous, as it can prevent
your stabilizer bar from doing its job properly. You may lose some elements of control when cornering,
and you’ll definitely notice additional noise
SUSPENSION SPRINGS
Fig. 3.10
Most cars today have shocks in the rear and spring/strut assemblies in the front. Both struts and
shocks work very similarly, and the biggest difference between the two setups is the presence of
suspension springs on the front (note that some cars do have springs in the rear).
Suspension springs are made from coiled steel, and are usually painted to protect them from rust and
deterioration. They’re very strong (they have to be to help support the weight of the car’s front end and
engine while driving). Your suspension springs work all the time. They’re under more stress while
you’re driving, but they must also bear weight while the car is parked.
Over time, suspension springs will begin to sag a bit, and they can lose some of their “springiness”..
They can also be damaged by rust and corrosion if the paint is worn off, exposing the underlying metal
to the elements.
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AIR SPRING
Fig. 3.11
The most common suspensions systems in today’s vehicles still consist of gas shocks and struts, but
liquid and air based systems are becoming increasingly more common and more popular. This is simply
because they are more comfortable. They are also easily adjusted for specific needs, like the height of
the driver or passengers. Air springs are just rubber bladders that are located under the vehicle, and work
to raise the chassis above the axles. They’re not all that complicated, and usually they will last a very
long time.
Rubber can always dry out, crack, and leak as it becomes brittle. If that happens, then naturally, you will
have to replace your air springs. Your suspension is a very important component when it comes to safe
operation of your vehicle, so you should never ignore signs of problems with your air springs.
Signs that your air springs need to be replaced include: Sagging suspension, Reduced maneuverability,
Air spring compressor keeps running, Leaking air
BALL JOINT
Your car’s rear ball joints are part of the suspension system, connecting the control arms to the wheels
and enabling you to steer your vehicle. The ball joints allow the wheels and the control arms to work
with one another, as well as working independently. Depending on the make and model of your vehicle,
your rear ball joints may either be serviceable, or sealed. Serviceable ball joints can be lubricated as
necessary, whereas sealed ball joints are an enclosed unit containing grease that was installed at the time
of manufacture, and is intended to last the life of the ball joint.
Signs that your ball joints are failing include: Creaking sound, Shaky steering, Strange noises in
suspension, Car drifting
3.10
TRANSMISSION PROBLEMS
When it comes to automatic transmissions, fluid leaks and low fluid levels are probably the most
common problems owners experience, especially as a vehicle gets older and parts wear out.
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If you don't notice a puddle of transmission fluid (often red, but sometimes other colors or clear) on your
garage floor or driveway, you might observe that the transmission is slow to engage a drive gear or
shifts sluggishly into higher gears while you're underway. Both are signs that the transmission fluid is
low, which usually can be traced to a leak, though other issues could be at fault. Transmission fluid also
can wear out over time and may need to be replaced.
Another warning sign is shifting harshly into the next gear instead of engaging smoothly, or slipping out
of a gear while driving. If you hear a grinding noise from the transmission, that could be because
bearings have failed, allowing metal-to-metal contact between parts that aren't supposed to rub against
each other.
Some vehicles have transmission-warning lights that illuminate when computers sense a problem, but on
many cars, the transmission is linked to the same computer that controls the engine, which is the
powertrain control module. That could result in the check engine light coming on when you have a
transmission issue.
Because modern transmissions are electronically controlled, if the software or even a sensor fails, the
transmission won't be getting the signals it needs. That could cause a transmission to shift into a "limp
home" mode that allows you to drive at reduced speed until it can be repaired. In some cases, a
transmission will just shut down to prevent further damage.
Possible signs a transmission system might give you are:
Slipping: When an automatic transmission seems to slip in and out of gear, or the engine revs up but the
vehicle goes much slower than the engine seems to be running, it's known as slipping. Sometimes the
gears reengage harshly.
Shuddering: This is where the whole vehicle shudders and shakes while driving, as if it's having a
convulsion. It feels like you're driving over rumble strips even if you're on a smooth highway.
Neutral Drop-Out: A condition that feels similar to slipping, neutral drop-out is where the transmission
drops into Neutral when the vehicle comes to a stop or while driving, typically at slower speeds.
Sometimes when driving, the trans drops out of gear resulting in the engine racing up, and then either
sliding — or banging — back into gear, or you step on the gas and the engine revs but the vehicle goes
nowhere as if it's in Neutral.
Heavy Drivetrain Vibration: This heavy vibration is felt throughout the vehicle under acceleration,
especially when the drivetrain is under load, such as driving up a hill or pulling a trailer. Though many
things can make a car vibrate, this type of drivetrain vibration will subside when coasting or idling.
Are Manual Transmissions Cheaper to Repair and Maintain Than Automatics?
Manual transmissions are usually cheaper to maintain and repair than automatics because the latter are
far more complex and have more parts and functions that can fail, but it may depend on your driving
style.
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An automatic has hundreds of mechanical, hydraulic and electronic helpers that have to work in
harmony to shift gears smoothly for you. In contrast, a manual transmission is mostly mechanical gears
that rely on the driver to engage the clutch and shift when needed.
The cost of replacing automatic transmission fluid generally ranges from about ₦2,800 to ₦3,500,
depending on the vehicle and who is doing the work. Manual transmissions also require periodic fluid
changes, but the cost tends to be about half of that.
Transmission Valve
Fig. 3.12
The transmission valve body is the brain of the transmission. It controls the transmission shifts and
directs the appropriate fluids into the appropriate passages to aid in the shifting. All of this enables your
transmission to work properly and avoid damaging your entire transmission.
Transmission Valve Body Problems include: Metal Debris, Improper Lubrication, Worn Fluid
3.11
SENSORS
SPEED TIMING SENSOR
Fig. 3.13.0
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Engines needs a speed timing sensor (note that some engines have more than one speed timing sensor).
You might be more familiar with this as the crankshaft sensor.
Basically, the speed timing sensor is responsible for monitoring the teeth on the crankshaft as it spins.
The spin of the crankshaft actually creates a magnetic field around the sensor (which is a magnetic coil).
As the teeth pass, they create minute fluctuations in the field, which the sensor detects. This information
is transmitted to the car’s computer, which uses that data to adjust things like variable valve timing, the
amount of fuel to be injected into each cylinder and more.
Your car’s speed timing sensor is in use at any point that the engine is running. Because of that, it is
subjected to a lot of wear and tear. There are also other issues that could affect its longevity, including
contaminants, debris and the like. Additionally, the wiring harness could be damaged, which would
prevent the sensor from transmitting information to the car’s computer.
It’s important to know some of the more common symptoms of speed timing sensor failure so you can
be prepared for it. These include:
The Check Engine light is on in the dash, the engine runs rough (misfire), Loss of power from the
engine, The engine may not crank
MASS AIR FLOW SENSOR
Fig 3.13.1
The right amount of air and fuel in your engine is a vital component in keeping the engine running as it
should. Making sure that all of the vital components of the air and fuel system are running at peak
condition is the best way to keep a car running at peak condition. The mass airflow sensor records the
amount of air that is coming into the engine and will then calculate how much fuel is needed to offset it.
Without a properly working mass airflow sensor, it will be nearly impossible to keep your car running as
intended. Addressing the issues with the mass air flow sensor in a hurry will reduce the amount of
trouble that you have and can also reduce the damage that is done to the vehicle.
When your mass air flow sensor is going bad, here are some of the things that you may notice: The car
does not have the power that it once did, there is an excessive amount of fuel being used, the car will not
start due to carbon clogging the sensor, the Check Engine Light is on
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Taking these signs seriously and getting the right repairs performed will help to restore the performance
that your car has lost. Having professionals perform this type of repair is the best way to get the right
results.
SPEED SENSOR
Fig. 3.13.2
The vehicle speed sensor (VSS) is usually located on the transmission’s output shaft (although it can be
located in other areas). It’s responsible for sending a signal to the car’s computer that tells it how fast the
vehicle is traveling.
The speed sensor is also tied into the car’s anti-lock braking system and helps provide information that
is used in determining when ABS should be activated and when it shouldn’t be.
The speed sensor is in use any time your car is in motion. Thus, it’s exposed to a lot of heat, wear and
tear.
If your car’s speed sensor begins to fail, you’ll notice a very wide range of possible symptoms. These
include:
Inconsistent speedometer readings (the needle does not maintain a reading even though you’re driving at
a steady speed), Check Engine light is on, the transmission sounds like it is revving very high before
shifting, the speedometer doesn’t work, the overdrive light flashes, the transmission struggles to shift
into the highest gear, the ABS light is on in the dash
EVAPORATOR TEMPERATURE SENSOR
Fig. 3.13.3
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If you have air conditioning in your vehicle, which pretty much all modern vehicles have, then you have
an evaporator temperature sensor (switch). This switch plays an important role in making sure the
correct temperature is attained, and that it doesn't get too cold and then form frost on your evaporator
core. This sensor can be found on the evaporator housing or the evaporator itself. Its purpose is to keep
track of the temperature of the evaporator.
Once this part becomes faulty and is no longer working, it won't be taking the correct temperature
readings. This means that either too little or too much refrigerant can be released into the evaporator,
and create the wrong temperature. It’s a delicate balance of keeping that exact right temperature, so the
temperature sensor is quite an important component.
OIL PRESSURE SENSOR
Fig. 3.13.4
The lubrication that the oil in your engine offers is important in maintaining the car’s functionality. A
variety of parts go into ensuring that the oil supply in a car stays at peak levels. Making sure that the
pressure level of the oil is right is the job of the oil pressure sensor. The oil pressure sensor helps to send
the information regarding the oil pressure to the gauge that is located on the instrument cluster. In order
to keep a car running smoothly, you will have to be alerted when there is a problem with the oil
pressure. By having a fully functional pressure sensor, you will be able to get this information easily.
For the most part, you will not give your oil pressure sensor any thought until there are repair issues.
The location and important role that this part plays in your engine is a big reason why allowing a
professional to replace the oil pressure sensor would be a good idea.
Here are some of the things that you will notice when your oil pressure sensor is going out:
The Oil Pressure light is on
The oil pressure gauge is erratic
The Check Engine light is on
As soon as you begin to notice that these symptoms are showing up, you will have to take the time to get
the appropriate repairs.
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THROTTLE BODY TEMPERATURE SENSOR
Fig. 3.13.5
The throttle body is an important part of your vehicle and should be monitored regularly. The throttle
body temp sensor is a sensor that is mounted on the throttle body. It monitors the temperature of the
throttle body and then sends the information directly to the engine control module. From there, the
module figures out the best fuel flow for the engine. As for failure, there are a few signs to watch for
that can point to a faulty throttle body temp sensor. Let’s take a look:
When your engine is hot you may have a problem getting the engine started. This can be
intermittent rather than every single time the engine is hot.
When you are idling, you may have issues with stalling since the air and fuel mixture will be off.
This can begin as intermittent and then become more common as the part continues to fail. Take
this as an early warning sign to get it into the mechanic and checked out.
The engine may also give you issues when you accelerate, which is not only frustrating but
dangerous. Again it goes back to the improper mixture of fuel and air. In order for your engine to
perform at its peak level it needs the right mixture.
The throttle body temp sensor is a key component in making sure your engine receives the perfect
combination of fuel and air. Without that right combination the engine won’t be able to run as
effectively and efficiently as it is meant to
SPEEDOMETER SENSOR
While a mechanical speedometer will use a speedometer cable attached to the driveshaft and
transmission, that’s not the case with an electronic speedometer, such as is used in most modern
vehicles. These use a speedometer sensor. It’s mounted to the transmission, but there is no cable that
connects it to the back of the speedometer housing. Instead, it sends a series of pulses to the car’s
computer, which interprets those signals, and then displays them as the speed at which you’re traveling.
Each vehicle requires a specific speedometer sensor calibrated for its unique specifications. In addition,
the speedometer sensor is in use at all times when your car is on the road. If you’re moving, the sensor is
sending signals to the computer. The good news is that mechanical failure isn’t a problem (it’s an
electronic component). The bad news is that electronic components can still fail early.
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Damage to the wiring harness, exposure to caustic fluids, and many other things can cause problems
with the sensor. Debris can also build up around the base of the sensor, which actually mounts inside the
transmission housing. If your speedometer sensor fails, your speedometer itself will be unreliable. It
might not work at all in a worst-case scenario. Knowing a few common symptoms to watch for can help
make this situation easier to deal with. They include:
Speedometer doesn’t work, Speedometer is inaccurate (reading too high or too low), Speedometer
needle bounces, or digital readout changes randomly, Check Engine light is on, Cruise control doesn’t
work
TOP DEAD CENTER SENSOR
The top dead center (TDC) sensor is the point from which the firing order is determined and the ignition
system measurements are taken. The measurements are normally defined as before top dead center and
after top dead center. The TDC is meant to be a reference point that tells the spark plugs when it should
fire and ignite the fuel in the combustion chamber.
Over time, the sensor can go bad due to becoming old, wearing out, cracking or starting to corrode
because of the harsh operating environment. If the sensor goes bad, the engine control module will not
receive the correct signal and the spark may be sent to the wrong cylinder at the wrong time. This can
cause your vehicle to have issues running, or it may cause the engine to not run at all. Two of the biggest
signs your TDC sensor is bad is the Check Engine Light will come on and your vehicle will not start.
Since the TDC sensor can go bad over time, it is important that you can recognize the symptoms that
indicate it needs to be replaced.
Signs that point towards the top dead center sensor going bad include: The Check Engine Light
comes on, your vehicle misfires or runs poorly while idling or driving, the engine will not run at all,
causing you vehicle not to turn on, Backfiring from the exhaust system
3.12
SPARK PLUG
Spark plugs are an integral part of your vehicles motor as they provide the much needed spark that
ignites the air and fuel mixture within the cylinders. This continuous ignition is what keeps your car
moving on the road.
If spark plugs are not checked with regular services, cleaned or changed when necessary, they can cause
problems to occur with the vehicles engine. Below are six signs for when to change your spark plugs:
When to change spark plugs:
1.Engine has a rough idle
2. Having trouble starting your car?
3. Your engine misfires
4. Engine surging
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5. High fuel consumption
6. Lack of acceleration
3.13
FUEL INJECTOR
Fig. 3.14
Fuel injectors, as their name implies, are responsible for getting fuel into the engine. Fuel injection
systems either work via a throttle body containing as few as 2 injectors, or go straight into the port with
one injector per cylinder. The injectors themselves spray gas into the combustion chamber like a spray
bottle, allowing the gas to mix with air before ignition. The fuel is then ignited and the engine keeps on
moving. If the injectors become dirty or clogged, the engine cannot run as smoothly.
The Role of Fuel Injectors
Fuel injectors play a very important role in the engine's fuel delivery system in that they deliver the
exact amount of gasoline that the engine needs, even as the requirements shift quickly and constantly.
An injector is a valve with electronic controls that receives signals from the engine control unit. A gas
pump delivers pressurized gasoline into the fuel injectors and the engine control unit tells the fuel
injectors to open a valve to let the pressurized gas pass through an atomizing nozzle. The fuel injectors
thereby spray a fine gasoline mist into the engine's intake manifold, which then delivers it to the
engine for combustion with the oxygen that the engine is receiving. This mist makes for more efficient
burning of the gas in combustion than if it were in droplet form. The more gasoline that the engine
requests, the longer the valves in the fuel injectors stay open. Pulse width describes the amount of
time that the valves stay open.
Common Problems
This section lists the most common problems that are associated with fuel injectors. Some problems
are easy to correct, while others require replacement of the fuel injectors. They include:
Dirty Fuel Injectors, Clogged Fuel Injectors, Fuel Injector Does Not Open, Fuel Injector Does Not
Close, Fuel Injector Leaks
Symptoms That Can Signify a Problem
The table below describes the various symptoms that can signify a possible problem with fuel
injectors. It also associates the problems detailed above with these symptoms.
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Symptoms
Inconsistent Engine
Power
Description
Associated Problems
An inconsistent fuel supply can cause
the engine to rev high and low, with the Dirty fuel injector
RPM gauge fluctuating.
Dirty fuel injector
Misfiring Engine
Uneven Engine Idling
Fuel Scent
When the fuel supply is inadequate
upon ignition, the engine might misfire. Clogged fuel injector
An 8 to 10 percent reduction in one fuel
injector can cause this to occur.
Fuel injector does not
open
An engine should idle smoothly, but an
uneven fuel supply will cause idling
disturbances.
Leaking fuel from a faulty fuel injector
will create a strong gasoline smell.
Dirty fuel injector
Fuel injector does not
close
Fuel injector leaks
Diminished Gas
Mileage
A fuel injector that delivers drops of
gasoline instead of a mist will make for
inefficient use of the gas, reducing the
car's gas mileage.
Fuel injector does not
close
Fuel injector leaks
Table 1
Being able to observe these symptoms is an important aspect of realizing that there is a problem with a
car, and being able to associate these symptoms with specific fuel injector problems will help car
owners to resolve the issues with their injectors quickly.
3.14
CYLINDER HEAD GASKET
Understanding why a relatively inexpensive head gasket costs so much to replace means first realizing
what it sits between. In the engine block are pistons that travel up and down in cylinder bores. The
pistons are connected to rods, which in turn are connected to a spinning crankshaft from which the
vehicle takes its power. Bolted to the top of the engine is the cylinder head. Inside the cylinder head are
valves that open and close to let air and fuel into the cylinders and expel the spent exhaust gas.
The head gasket is compressed between the engine block and the cylinder head. The head gasket seals in
the internal combustion process and also keeps coolant and oil from mixing together as the two fluids
travel from the engine block to the cylinder head. Head gaskets themselves are not very expensive. What
ends up costing big money is getting to it. Head gasket repairs mean undertaking the major operation of
removing an engine's head.
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3.15 HYBRID ELECTRIC VEHICLES
Fig. 3.15
Hybrid electric vehicles (HEVs) combine the benefits of gasoline engines and electric motors. They can
be designed to meet different goals, such as better fuel economy or more power.
Most hybrids use several advanced technologies:
Regenerative Braking. Regenerative braking recaptures energy normally lost during coasting or
braking. It uses the forward motion of the wheels to turn the motor. This generates electricity and
helps slow the vehicle.
Electric Motor Drive/Assist. The electric motor provides power to assist the engine in
accelerating, passing, or hill climbing. This allows a smaller, more-efficient engine to be used. In
some hybrids, the electric motor alone propels the vehicle at low speeds, where gasoline engines
are least efficient.
Automatic Start/Stop. Automatically shuts off the engine when the vehicle comes to a stop and
restarts it when the accelerator is pressed. This reduces wasted energy from idling.
Fig. 3.16
The batteries in modern hybrids are designed to last for at least 100,000 miles. Some might even make it
to 150,000 or more. If you're the original owner of a hybrid vehicle, chances are you won't ever have to
replace the battery pack because it just wears out.
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That said, hybrid batteries aren't immune to the laws of nature. Just like any other car part, they can
unexpectedly fail. That's why automakers provide lengthy warranties. The battery pack in the Toyota
Prius and Toyota Camry is guaranteed for 100,000 miles. Honda and Ford stand behind theirs for 80,000
miles. It's safe to say that replacement is a rare event.
A pair might be replaced if the launch scanner indicates the exact pair that is damaged or that loses
voltage excessively as this might prevent the entire pack from working.
V
Fig. 3.17
3.16
SIX STEP APPROACH
At this stage it is important to emphasize the need to be methodical. A simple but effective approach is
diagnostic work know as six step approach.
This six-step approach maybe, recognized as an organized approach to problem solving in general. As
quoted here it may be seen that certain steps are recursive. That is to say it may be necessary to previous
steps as one proceeds to solution.
The six steps are:
1. Collect evidence;
2. Diagnose the vehicle using an auto scanner;
3. Locate the fault (using the fault codes if available);
4. Find the cause of the fault and remedy it;
5. Rectify the fault (if different from 4)
6. Test the system to verify that repair is correct and clear the fault codes.
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CHAPTER 4
ON-BOARD DIAGNOSTICS (OBD) SYSTEM
What Is the On-Board Diagnostics (OBD) System?
Fig. 4.1
Your car contains a vast number of different systems, all of which must work in harmony to ensure
proper operation. There must be a way to monitor your ignition and emissions systems and the OnBoard Diagnostics (OBD) is a computer that keeps tabs on what’s going on with your vehicle.
What the OBD system does
Simply stated, the OBD system is an on-board computer that communicates with other systems,
including the ECU, TCU and more. It monitors the performance of your ignition system, engine
performance, transmission operation, emissions system operation and more. Based on feedback from
sensors around the vehicle, the OBD system determines if everything is working properly, or if
something is beginning to go wrong. It’s advanced enough to warn drivers before a serious problem
occurs, often at the first symptom of a failing component.
When the OBD system identifies an issue, it turns on a warning light in the dash (generally, the Check
Engine Light), and then stores a trouble code (called a DTC, or diagnostic trouble code). A mechanic
can connect a scan tool to the OBD II connector under the dash and read this code. This provides the
information needed to begin the diagnostic process. Note that reading a code does not necessarily mean
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that the mechanic knows immediately what has gone wrong, but that the mechanic has a place to begin
looking.
As a note, the OBD system also determines whether your car will pass emissions testing. If the Check
Engine Light is on, your car won’t pass the test. There’s also a chance that it won’t pass even if the
Check Engine Light is not on.
DO ALL VEHICLES HAVE OBD SYSTEM?
Today’s cars are equipped with sophisticated technology. The OBD system (on-board diagnostics) is
actually advanced enough to monitor several critical systems on your vehicle and warn you when
something starts to go wrong, which can prevent serious damage in the long run.
Not all cars have an OBD system
OBD has been around for a long time, but not all vehicles have this system. OBD I, the first version, was
introduced as early as the 1960s, but it wasn’t mandatory on all cars. Some automakers included it from
the beginning, but others didn’t adopt it until later on.
OBD II came along later, but it was not made mandatory until 1996. From that point onward, all
vehicles sold in the US were required to have an OBD II system. This meant that all vehicles had the
same type of connector located somewhere under the dash, and that most of the trouble codes were
standardized. Note that not all trouble codes are standard or open for access. Some are automakerspecific and cannot be read without an advanced scan tool (a consumer-grade code reader will not do
this).
OBD II also surpassed OBD I in other ways. For instance, OBD I systems would only turn on the Check
Engine Light after a failure. OBD II systems are able to monitor gradual deterioration of a system and
turn on the Check Engine Light before a failure.
Unlike OBD I, which was a general monitoring system for vehicles, OBD II systems are highly focused
on emissions and related systems. While the OBD II system also monitors engine and transmission
performance, emissions control is the primary reason it was instituted.
How Can I Tell If The OBD System Is Working?
Today’s cars are far more sophisticated than they once were, and they require a computer to monitor and
manage the various systems so that everything works together properly. This also gives you the means
to determine if there’s something going wrong with your car. The OBD II system (On Board
Diagnostic) is a system that allows a mechanic to communicate with your car’s computer and pull
trouble codes in many situations. These codes tell the mechanic where the trouble is, but not necessarily
what the actual problem is.
How to tell if the OBD is working?
Determining if your OBD system is working is actually very simple.
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Start with the engine off. Turn the key to "on," and then run so that the engine cranks. Watch the dash
during this time. The Check Engine Light should flash on, and stay on for a brief period. It should then
turn off. The brief flash on is the signal that the system is up and running, and ready to monitor your
vehicle during operation.
If the Check Engine Light comes on and stays on, then there’s a trouble code (DTC) stored in the
computer that indicates a fault somewhere in the engine, the transmission or the emissions system. This
code should be checked by a mechanic so that an accurate repair can be made.
If the Check Engine Light does not flash and turn off (or if it never comes on at all), it’s a sign that there
is something wrong with the system, and it must be checked by a professional mechanic.
Your vehicle will not pass annual testing without an operable OBD system, and you will also have no
way of knowing if something is wrong with the vehicle.
OBD-II Codes Explained
OBD-II codes consist of a number of parts. Here is a sample OBD2 code: P0171
Here is a breakdown of what each digit of the code means:
First Character - System
The first character identifies the system related to the trouble code.
P = Powertrain
B = Body
C = Chassis
U = Undefined
Second Digit - Code Type
The second digit identifies whether the code is a generic code (same on all OBD-II equipped vehicles),
or a manufacturer specific code.
0 = Generic (this is the digit zero -- not the letter "O")
1 = Enhanced (manufacturer specific)
Third Digit - Sub-System
The third digit denotes the type of sub-system that pertains to the code
1 = Emission Management (Fuel or Air)
2 = Injector Circuit (Fuel or Air)
3 = Ignition or Misfire
4 = Emission Control
5 = Vehicle Speed & Idle Control
6 = Computer & Output Circuit
7 = Transmission
8 = Transmission
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9 = SAE Reserved
0 = SAE Reserved
Fourth and Fifth Digits
These digits, along with the others, are variable, and relate to a particular problem.
NOTE: A list of all standard diagnostic trouble codes (DTC's) that are used by some manufacturers to
identify vehicle problems can be found at ‘REFERENCE 4’
Launch X431 IV Scanner
This is the type of auto scanner that we used in the firm I carried out my internship
Fig. 4.2
Launch X431 IV car list:
Acura, Changan, Daweoo, Gaz, Hafei, Huachen, Jiao, Lexus, Xiali, Xinkai, Benz, Fiat, Holden, Maruti,
Opel, Peugeot, Saab, Ssangyong, Tata, Changhe, Flyer, GMSA, Infiniti, Mahindra, Perodua, Proton,
Qirui, Tlisuzu, Zhongshun, EOBD2, Euro ford, GM, Jaguar, Renault, Smart, Sprinter, USA Ford, VAZ,
VW, Changcheng, Dacia, Ford, Hao Qing, Jinlong, Liuwei, Rover, Zhong Tai, Zhong Xing, Bx fiat,
HM, Isuzu, Jacty, JP Isuzu, Mazda, Seat, Skoda, Suzuki, BMW, Daihatsu, Mitsubishi, Porsche, Toyota,
Volvo, Audi, Chrysler, Citroen, Hyundai, Kia, Lancia, Landrover, Nissan, Romeo and Subaru
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CHAPTER 5
4.2 OBSERVATIONS AND CONTRIBUTIONS
OBSERVATIONS
As a student my first observation was the cognition of the difference between the school environment
and the labor market, as it is a different ball game entirely.
I also observed that safety was paramount and it could easy be seen as the primary goal of every staff of
the company and not only the technicians. As safety equipment and instructions were always put in
place or made available at strategic locations within the company. workshop to the service desks to the
customer care centers to the offices to the receptions.
Neatness was also a key attribute as even though the job is usually seen as a dirty job, technicians were
always admonished to be as neat as possible in their dressing and in carrying out their duties. This was
further encouraged by rewarding technicians that could fully adhere to this
- The hospitality shown to customers was of another level as customers were treated with so much
care and respect. From provision of free breakfast and lunch, to a brief internal training, to free
medical checkup the customers were always made to feel at ease.
- Communication played a vital role in the successful execution of jobs, from among personnel in a
section to departments communicating with other departments present in the company and also
customers with company’s personnel. Good flow of information was required and as a result most
jobs that were returned or problematic, come about as a result of poor communication between
parties.
4.2 CONTRIBUTIONS
My contributions were shown in my work done and services given as a Diagnosing / Mechanical
technician in the establishment, which was basically diagnosing and repair of mechanical components of
automobiles. I was able to maximize the job efficiency and work output in my section, because after a
couple of months my section supervisor gave me the access to work directly with the spare parts and
material store department, thereby speeding up the job completion process, as he wasn’t always around
to attend due to official reasons. I was also able to revive the job registration process as it was slightly
overlooked prior to my attachment because of the magnitude of work in the section, but after
successfully reviving it, it became useful in double-checking the vehicles that came into the section and
technicians that worked on them
Also, I introduced a pump mechanism of refilling the differential fluid which runs out during the
changing of a wheel bearing and hub assembly
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CHAPTER 6
CONCLUSION AND RECOMMENDATION
5.0 CONCLUSION
My 6months industrial attachment as a junior technician at Autogenius Royal Motors was a huge
success and a great time of acquisition of knowledge and skills. Through my training I was able to
appreciate my chosen course of study even more, because I had the opportunity to blend the theoretical
knowledge acquired from school with the practical hands-on application of knowledge gained here to
perform very important tasks that contributed in a way to my productivity in the company.
My training here has given me a broader view to the importance and relevance of Mechanical Engineers
in the immediate society and the world as a whole, as I now look forward to impacting it positively after
graduation. I have also been able to improve my communication and presentation skills and thereby
developed good relationship with my fellow colleagues at work. I have also been able to appreciate the
connection between my course of study and other disciplines in producing a successful result.
5.1 RECOMMENDATION
I use this means to make the following recommendations concerning the training of students in
Industrial Attachments
i. I would like to recommend that the Engineering curriculum in the University of Benin be adjusted
such as would provide going on industrial attachments for a longer period of time as opposed to 6
months or making the program to occur twice throughout an engineering degree program.
ii. Allowances should be paid to students during their programme just like NYSC and not after. This
would help them a great deal to handle some financial problems during their training course.
5.2 CHALLENGES ENCOUNTERED DURING PERIOD OF TRAINING
I wasn’t given transportation or feeding money during my training period at the company, which means
I had to feed and transport myself. Also I wasn’t allowed to drive cars after repair. So I could not do
active test using Diagnostic machines on my own. And I was not allowed to go out to repair car. I was
restricted to the workshop.
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REFERENCES
1. Taylor, C. F.: The Internal Combustion Engine in Theory and Practice, vol. I, p. 506, MIT Press.
2. Society of Automotive Engineers (1998). Automotive Engineering Handbook. Warren dale, PA:
Society of Automotive Engineers, Inc.
3. SIWES. (2008). Retrieved January 2015, from ITF: http://odich.com/itfnig/siwes.php
4. Paul Dempsey. (November 5, 2007). 4th Edition: Troubleshooting and Repair of Diesel Engines
5. wikipedia.com/automobile/dictionary
6. 1998 NAPA Institute of Automotive Technology. Introduction to OBD II
7. http://www.obd-codes.com/trouble_codes/
8. Charles Fayette Taylor, 1995, The Internal Combustion Engine in Theory and Practice: Volume 1 & 2
9. Willard W. Pulkrabek : Engineering Fundamentals of the Internal Combustion Engine
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