Ch. 83 Evaporative Emission Control
Systems
What is the substance used in a vapor canister to absorb volatile organic compounds? -
answer Carbon
Which valve(s) is (are) normally closed? - answerCanister purge valve
All of the following can increase pressure in the evaporative emission control system
except ____. - answerInlet fuel to the fuel pump
Evaporative emission control systems operate on low pressure measured in inches of
water (inch H2O). One PSI is equal to how many inches of water? - answer28
Inadequate purge flow rate will trigger which DTC? - answerP0446
Two technicians are discussing a state emission test. Technician A says that a vent
valve that is not able to close can cause the system to fail the on-board test. Technician
B says that a leaking gas cap can cause a failure of the EVAP test. Which technician is
correct? - answerBoth technicians A & B
Which EVAP valve is subject to rust and corrosion more than all of the others? -
answerVent valve
Before an evaporative emission monitor will run, the fuel level must be where? -
answerbetween 15% and 85% full
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? - answerBoth
technicians A & B
A small 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? - answerEither P0440,
P0441, or P0442
The volume of the upper volume chamber that allows for expansion of the fuel when hot
is between ________ of the volume of the tank. - answer10% and 20%
Systems
What is the substance used in a vapor canister to absorb volatile organic compounds? -
answer Carbon
Which valve(s) is (are) normally closed? - answerCanister purge valve
All of the following can increase pressure in the evaporative emission control system
except ____. - answerInlet fuel to the fuel pump
Evaporative emission control systems operate on low pressure measured in inches of
water (inch H2O). One PSI is equal to how many inches of water? - answer28
Inadequate purge flow rate will trigger which DTC? - answerP0446
Two technicians are discussing a state emission test. Technician A says that a vent
valve that is not able to close can cause the system to fail the on-board test. Technician
B says that a leaking gas cap can cause a failure of the EVAP test. Which technician is
correct? - answerBoth technicians A & B
Which EVAP valve is subject to rust and corrosion more than all of the others? -
answerVent valve
Before an evaporative emission monitor will run, the fuel level must be where? -
answerbetween 15% and 85% full
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? - answerBoth
technicians A & B
A small 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? - answerEither P0440,
P0441, or P0442
The volume of the upper volume chamber that allows for expansion of the fuel when hot
is between ________ of the volume of the tank. - answer10% and 20%
