OBJECTIVES
After studying Chapter 26, the reader will be able to:
1. Prepare for the ASE Engine Performance (A8)
certification test content area “D” (Emission
Control Systems).
2. Describe the purpose and function of the
evaporative emission control system.
3. Discuss how the evaporative emission control
system is tested under OBD-II regulations.
4. Explain methods for diagnosing and testing faults
in the evaporative emission control system.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
NEED FOR EVAPORATIVE EMISSION CONTROL
• The purpose of the evaporative (EVAP) emission control
system is to trap and hold gasoline vapors.
• The charcoal canister is part of an entire system of hoses
and valves.
• Before the early 1970s, most gasoline fumes were simply
vented to the atmosphere.
• The purpose of the EVAP system is to trap gasoline
vapors—volatile organic compounds, or VOCs—that
would otherwise escape into the atmosphere.
• These vapors are instead routed into a charcoal canister,
from where they go to the intake airflow so they are burned
in the engine.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
NEED FOR EVAPORATIVE EMISSION CONTROL
Common Components
• Most EVAP fuel tank filler
caps have pressurevacuum relief built into
them.
• When pressure or vacuum
exceeds a calibrated value,
the valve opens.
• Once the pressure or
vacuum has been relieved,
the valve closes.
FIGURE 26-1 A typical bayonet-type gas cap.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
VAPOR CANISTER STORAGE
• The canister is located
under the hood or
underneath the vehicle, and
is filled with activated
charcoal granules that can
hold up to one-third of their
own weight in fuel vapors.
• A vent line connects the
canister to the fuel tank.
FIGURE 26-2 Charcoal canister as
mounted under the hood (Jeep). Not all
charcoal canisters are this accessible; in
fact, most are hidden under the hood or in
other locations on the vehicle.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
VAPOR CANISTER STORAGE
FIGURE 26-3 The evaporative emission control system includes all of the lines,
hoses, and valves, plus the charcoal canister.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
VAPOR PURGING
• During engine operation, stored vapors are drawn
from the canister into the engine through a hose
connected to the throttle body or the air cleaner.
• This “purging” process mixes HC vapors from the
canister with the existing air-fuel charge.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
VAPOR PURGING
Computer-Controlled Purge
• Canister purging on engines with electronic fuel
management systems is regulated by the
powertrain control module (PCM).
• Control of this function is particularly important
because the additional fuel vapors sent through the
purge line can upset the air–fuel ratio provided by a
fuel-injection system.
• Since air–fuel ratio adjustments are made many
times per second, it is critical that vapor purging is
controlled just as precisely.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
VAPOR PURGING
Computer-Controlled Purge
FIGURE 26-4 A typical evaporative
emission control system. Note that when
the computer turns on the canister purge
solenoid valve, manifold vacuum draws any
stored vapors from the canister into the
engine. Manifold vacuum also is applied to
the pressure control valve. When this valve
opens, fumes from the fuel tank are drawn
into the charcoal canister and eventually
into the engine. When the solenoid valve is
turned off (or the engine stops and there is
no manifold vacuum), the pressure control
valve is spring-loaded shut to keep vapors
inside the fuel tank from escaping to the
atmosphere.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
EVAPORATIVE SYSTEM PRESSURE
• Pressures can build inside the fuel system and are
usually measured in units of inches of water,
abbreviated in. H2O. (28 inches of water equals one
PSI).
• Pressure buildup is a function of:
–
–
–
–
–
–
Fuel evaporation rates (volatility)
Gas tank size (fuel surface area and volume)
Fuel level (liquid versus vapor)
Fuel slosh (driving conditions)
Temperature (ambient, in-tank, close to the tank)
Returned fuel from the rail
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
NONENHANCED EVAPORATIVE CONTROL
SYSTEMS
• Nonenhanced evaporative
systems use either a
canister purge solenoid or a
vapor management valve to
control purge vapor.
FIGURE 26-5 A typical OBD-II EVAP
system which uses fuel tank pressure
and purge flow sensors to detect leaks
and measure purge flow. The purge
flow sensor is similar to a mass air flow
sensor and measures the amount of
flow into the engine.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
ENHANCED EVAPORATIVE CONTROL SYSTEM
• All vehicles built after 1995 have enhanced
evaporative systems that have the ability to detect
purge flow and system leakage.
• If either of these two functions fails, the system is
required to set a diagnostic trouble code and turn
on the MIL light to warn the driver of the failure.
• Vent Valve
• Purge Valve
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
ENHANCED EVAPORATIVE CONTROL SYSTEM
FIGURE 26-6 The vapor
management valve (VMV)
and the canister purge
valve (CPV) are both PCM
controlled and check for
proper flow through the
evaporative control system.
The fuel tank pressure
(FTP) sensor monitors
vapor pressure inside the
fuel tank.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
ONBOARD REFUELING VAPOR RECOVERY
• The primary feature of most ORVR systems is the
restricted tank filler tube, which is about 1 inch (25
mm) in diameter.
• This reduced filler tube creates an aspiration effect,
which tends to draw outside air into the filler tube.
• During refueling, the fuel tank is vented to the
charcoal canister, which captures the gas fumes:
with air flowing into the filler tube, no vapors can
escape to the atmosphere.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
STATE INSPECTION EVAP TESTS
• In some states, a periodic
inspection and test of the
fuel system are mandated
along with a dynamometer
test.
• The emissions inspection
includes tests on the
vehicle before and during
the dynamometer test.
FIGURE 26-7 A gas cap being testing by
an inspector at an inspection station.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
DIAGNOSING THE EVAP SYSTEM
• Before vehicle emissions testing began in many
parts of the country, little service work was done on
the evaporative emission system.
• Common engine-performance problems that can be
caused by a fault in this system include:
– Poor fuel economy
– Poor performance
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
DIAGNOSING THE EVAP SYSTEM
FIGURE 26-8 A typical purge
flow tester connected in
series between the intake
manifold (or control solenoid)
and the charcoal canister.
Most working systems should
be capable of flowing at least
1 L/min. Some vehicles must
be test driven because their
computers only purge after a
certain road speed has been
achieved.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
LOCATING LEAKS IN THE SYSTEM
• Leaks in the evaporative emission control system will cause
the malfunction check gas cap indication light to come on in
some vehicles.
FIGURE 26-9 Some vehicles will display a message if an evaporative control
system leak is detected that could be the result of a loose gas cap.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
LOCATING LEAKS IN THE SYSTEM
• There are two methods that can be used to check
for leaks in the evaporative system.
– Smoke machine testing.
– Nitrogen gas pressurization.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
LOCATING LEAKS IN THE SYSTEM
FIGURE 26-10 (a) A typical EVAP diagnostic tester. (b) A smoke test shows a
leaking gas cap.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
LOCATING LEAKS IN THE SYSTEM
FIGURE 26-11 An emission tester that uses nitrogen to pressurize the fuel system.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
EVAPORATIVE SYSTEM MONITOR
• The EVAP system monitor
tests for purge volume and
leaks.
• Most applications purge the
charcoal canister by
venting the vapors into the
intake manifold during
cruise.
• To do this, the PCM
typically opens a solenoidoperated purge valve
installed in the purge line
leading to the intake
manifold.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
FIGURE 26-12 Typical evaporative system
showing the valves and the normal
position.
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
EVAPORATIVE SYSTEM MONITOR
Engine Off Natural Vacuum
• System integrity (leakage) can also be checked
after the engine is shut off.
– The premise is that a warm evaporative system will cool
down after the engine is shut off and the vehicle is stable.
• A slight vacuum will be created in the gas tank
during this cooldown period.
– If a specific level of vacuum is reached and maintained,
the system is said to have integrity (no leakage).
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
GENERAL MOTORS ENHANCED EVAP
• The PCM will run the EVAP monitor when the
following enable criteria are met.
• Typical enable criteria include:
–
–
–
–
–
–
–
Cold start
BARO greater than 70 kPa (20.7 in. Hg or 10.2 PSI)
IAT between 39°F and 86°F at engine start-up
ECT between 39°F and 86°F at engine start-up
ECT and IAT within 39°F of each other at engine start-up
Fuel level within 15% to 85%
TP sensor between 9% and 35%
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
GENERAL MOTORS ENHANCED EVAP
Running the EVAP Monitor
• There are four tests which are performed during a
typical GM EVAP monitor.
• A DTC is assigned to each test.
–
–
–
–
Weak Vacuum Test (P0440—large leak).
Small Leak Test (P0442—small leak).
Excess Vacuum Test (P0446).
Purge Solenoid Leak Test (P1442).
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
ALWAYS TIGHTEN “THREE CLICKS”
FIGURE 26-13 Some newer Fords use a fuel system that does not use a cap.
Carefully check the opening for dirt or debris if an evaporative system DTC is
set.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
FORD ENHANCED EVAP
• The PCM will run the EVAP monitor when the
following enable criteria are met.
– Cold start
– Inlet air temperature between 40°F and 100°F
– 6- to 8-hour engine soak timer must expire
• A PCM reset (without turning the ignition off) will
bypass the 6- to 8-hour engine soak timer.
–
–
–
–
Altitude less than 8,000 feet
Fuel level within 15% to 85% (40% min for 0.020 in. leak)
40 to 65 mph steady cruise
30-minute time limit for the monitor to run
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
FORD ENHANCED EVAP
Typical Ford Strategy
•
•
•
•
•
Phase 0—Initial Vacuum Pulldown.
Phase 1—Vacuum Stabilization.
Phase 2—Vacuum Hold and Decay.
Phase 3—Vacuum Release.
Phase 4—Vapor Generation.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
KEEP THE FUEL TANK PROPERLY FILLED
FIGURE 26-14 The fuel level
must be above 15% and below
85% before the EVAP monitor
will run on most vehicles.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
LEAK DETECTION PUMP SYSTEM
• Many Chrysler and some
other brands of vehicles
use a leak detection pump
(LDP) as part of the
evaporative control system
diagnosis equipment.
FIGURE 26-15 A leak detection pump
(LDP) used on some Chrysler vehicles
to pressurize (slightly) the fuel system
to check for leaks.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
LEAK DETECTION PUMP SYSTEM
Pump Period
• The time between LDP solenoid off and LDP switch
close is called the pump period.
• This time period is inversely proportional to the size
of the leak.
• The shorter the pump period, the larger the leak.
• The longer the pump period, the smaller the leak.
– EVAP large leak (>0.080): less than 0.9 seconds
– EVAP medium leak (0.040 to 0.080): 0.9 to 1.2 seconds
– EVAP small leak (0.020 to 0.040): 1.2 to 6 seconds
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
EVAP SYSTEM-RELATED DIAGNOSTIC TROUBLE
CODES (DTCs)
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
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SUMMARY
1. The purpose of the evaporative emission (EVAP)
control system is to reduce the release of volatile
organic compounds (VOC) into the atmosphere.
2. A carbon (charcoal) canister is used to trap and
hold gasoline vapors until they can be purged and
run into the engine to be burned.
3. Pressures inside the EVAP system are low and are
measured in inches of water (1 PSI = 28 in. H2O).
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
SUMMARY
4. A typical EVAP system uses a canister
purge valve, which is normally closed, and a
canister vent valve, which is normally open.
5. OBD-II regulation requires that the
evaporative emission control system be
checked for leakage and proper purge flow
rates.
6. External leaks can best be located by
pressurizing the fuel system with lowpressure smoke.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
REVIEW QUESTIONS
1. What components are used in a typical
evaporative emission control system?
2. How does the computer control the purging of the
vapor canister?
3. What is the difference between an enhanced and
nonenhanced evaporative control system?
4. How is a flow gauge used to diagnose the
evaporative emission control system?
5. What are the parameters (enable criteria) that
must be met for the evaporative system monitor to
run?
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
1. What is the substance used in a vapor canister to
absorb volatile organic compounds?
a)
b)
c)
d)
Desiccant
Organic absorber
Pleated paper
Carbon
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
1. What is the substance used in a vapor canister to
absorb volatile organic compounds?
a)
b)
c)
d)
Desiccant
Organic absorber
Pleated paper
Carbon
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
2. Which valve(s) is (are) normally closed?
a)
b)
c)
d)
Canister purge valve
Canister vent valve
Both canister purge and canister vent valve
Neither canister purge nor canister vent valve
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
2. Which valve(s) is (are) normally closed?
a)
b)
c)
d)
Canister purge valve
Canister vent valve
Both canister purge and canister vent valve
Neither canister purge nor canister vent valve
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
3. All of the following can increase the pressure in the
evaporative emission control system except _____
a)
b)
c)
d)
Fuel temperature
Returned fuel from the fuel-injection system
Inlet fuel to the fuel pump
RVP of the fuel
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
3. All of the following can increase the pressure in the
evaporative emission control system except _____
a)
b)
c)
d)
Fuel temperature
Returned fuel from the fuel-injection system
Inlet fuel to the fuel pump
RVP of the fuel
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
4. Evaporative emission control systems operate on
low pressure measured in inches of water (in.
H2O). One PSI is equal to how many inches of
water?
a)
b)
c)
d)
1
10
18
28
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
4. Evaporative emission control systems operate on
low pressure measured in inches of water (in.
H2O). One PSI is equal to how many inches of
water?
a)
b)
c)
d)
1
10
18
28
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
5. Inadequate purge flow rate will trigger which DTC?
a)
b)
c)
d)
P0440
P0441
P0300
P0301
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
5. Inadequate purge flow rate will trigger which DTC?
a)
b)
c)
d)
P0440
P0441
P0300
P0301
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
6. Two technicians are discussing a P0442 DTC.
Technician A says that it can be caused by a
leaking EVAP line. Technician B says that a
leaking gas cap can cause a failure of the EVAP
test. Which technician is correct?
a)
b)
c)
d)
Technician A only
Technician B only
Both Technicians A and B
Neither Technician A nor B
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
6. Two technicians are discussing a P0442 DTC.
Technician A says that it can be caused by a
leaking EVAP line. Technician B says that a
leaking gas cap can cause a failure of the EVAP
test. Which technician is correct?
a)
b)
c)
d)
Technician A only
Technician B only
Both Technicians A and B
Neither Technician A nor B
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
7. A flow gauge is being used to check for proper
canister pump flow rate. What is the specification
used by most emission test sites?
a)
b)
c)
d)
10 liters per minute
5 liters per minute
1 liter in 4 minutes
0.5 liter per hour
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
7. A flow gauge is being used to check for proper
canister pump flow rate. What is the specification
used by most emission test sites?
a)
b)
c)
d)
10 liters per minute
5 liters per minute
1 liter in 4 minutes
0.5 liter per hour
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
8. Before an evaporative emission monitor will run,
the fuel level must be where?
a)
b)
c)
d)
At least 75% full
Over 25%
Between 15% and 85%
The level of the fuel in the tank is not needed to run the
monitor test
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
8. Before an evaporative emission monitor will run,
the fuel level must be where?
a)
b)
c)
d)
At least 75% full
Over 25%
Between 15% and 85%
The level of the fuel in the tank is not needed to run the
monitor test
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
9. Technician A says that low pressure smoke
installed in the fuel system can be used to check
for leaks. Technician B says that nitrogen under
low pressure can be installed in the fuel system to
check for leaks. Which technician is correct?
a)
b)
c)
d)
Technician A only
Technician B only
Both Technicians A and B
Neither Technician A nor B
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
9. Technician A says that low pressure smoke
installed in the fuel system can be used to check
for leaks. Technician B says that nitrogen under
low pressure can be installed in the fuel system to
check for leaks. Which technician is correct?
a)
b)
c)
d)
Technician A only
Technician B only
Both Technicians A and B
Neither Technician A nor B
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
10. A large leak is detected by the evaporative
emission control system monitor that could be
caused by a loose gas cap. Which DTC will likely
be set?
a)
b)
c)
d)
P0440
P0442
P0446
Either P0440 or P0442
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
10. A large leak is detected by the evaporative
emission control system monitor that could be
caused by a loose gas cap. Which DTC will likely
be set?
a)
b)
c)
d)
P0440
P0442
P0446
Either P0440 or P0442
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458