Modern Auto Mechanics
By Bill Kuhl http://www.scienceguy.org Special Thanks Dave MacLeod
Increasingly modern vehicles are a marriage of electronics and
mechanical components. Special equipment and skills are needed to
keep these vehicles operating in top shape. Like almost any
profession continuing education will be necessary to keep
current with new technologies.
Vehicle Computer
Modern automobiles may show problems through fault lights that
correspond to fault codes that require electronic equipment to decipher.
Even with the proper test equipment like the Snap-on MODIS device
pictured above the problem can be complicated to diagnose as one
problem can generate multiple codes.
Newer vehicles have plug for diagnostic devices.
Proper adapter is needed to plug diagnostic device.
The Snap-on MODIS device can read engine fault codes and many types
of data. It could even be connected to the vehicle when driven monitoring
air, brakes, etc.
It is very important that students are comfortable reading graphs and be
able to interpret the data because the scales on the graphs are ever
changing.
Sensors communicate with the vehicle computer.
Quote from article by Dale J. Long website:
http://technologyinterface.nmsu.edu/winter99/manufacturing/long/long.html
“Automobile sensors can be classified into three basic areas: drive-train and
vehicle control, driver safety/comfort/information and emissions.
They are used to monitor temperature, gases, voltages/currents, vacuum and
torque to name a few. Twenty years ago, the typical automobile had
approximately five sensors. Today, over fifty sensors are used to control
everything from braking to the fuel delivery
system.” Dale J. Long
The carburetor used on vehicles before fuel injection.
Computer technology has enabled fuel injection systems to almost
completely replace the carburetor system used for many years before that.
By processing the data from a variety of sensors, the fuel-air mixture can be
more precisely controlled for a better operating engine.
Engines should start better, run smoother, are more fuel efficient and less
polluting.
Fuel injector
Electronics in newer cars have replaced the mechanicals parts that wear out
in older cars that had points and a distributor.
Before the new electronic ignition, cars would often require points to be
adjusted or replaced every 10,000 miles or so. Electronic ignition
provides more accurate spark timing which improves the combustion and
emissions.
Distributor and coil seen in this picture.
Relay
Points
Only balancing tires is not enough to ensure that there are not additional issues
with the tires that could be causing steering problems or causing the car to pull
when going driving down the road. Newer testing equipment such as the
StraightTrak Road Force Measurement System in the pictures above can check
for tire conditions such as “conicity”. Conicity can be a manufacturing glitch
where the tire’s tread has cured in a slight cone shape.
The modern method for checking the alignment of an
automobile utilizes electronic camera type sensors and a
computer to give readings for such as camber, toe, and
caster. Newer equipments sets up quicker which allow the
service provider to charge less yet make more money
because of the faster time for the alignment.
Auto mechanics students will increasingly need to be able to work
on radically different types of automotive technology now and in the
future.
The pictures below are of a transaxle from a Toyota Prius hybrid.
Hybrid cars unite a fuel powered engine and an electric motor to
increase fuel efficiency and reduce emissions. This system is
rather complex in that various techniques are employed to
increase efficiency such as charging batteries while braking,
turning off the engine while stopped, and assisting the power to
the wheels with electric power.