Test Bank for Automotive
Electrical and Engine
Performance
Magnetic pulse generators are commonly used to send data to the computer about: - ANSWERSThe
speed of the monitored component.
Technician A says pulse width modulation (PWM) is measured in a length of time, not a percentage
of a cycle. Technician B says that the cooling fan relay is usually controlled by the PCM through
PWM. Who is correct? - ANSWERSBoth A and B
When the pressure in the intake manifold increases the fuel pressure regulator on a port fuel
injection system: - ANSWERSIncreases fuel pressure.
Technician A says a P0300 is considered a generic DTC.
Technician B says a P1300 is considered a manufacturer specific DTC. - ANSWERSBoth A and B
The vent valve in an evaporative emissions system may be: - ANSWERSOpened to allow fresh air
through the charcoal canister and closed with the purge valve open while the PCM monitors the fuel
tank pressure sensor for vacuum.
Technician A says the computer may activate a circuit by completing the path to ground. Technician
B says the computer may activate a circuit by completing the path to power. Who is correct? -
ANSWERSBoth A and B.
Technician A states that non-contact type hall-effect sensors wear out very quickly.
Technician B states that some throttle position sensors are non-contact. - ANSWERSTechnician B
only.
The purpose of the PCV system is to: - ANSWERSControl emissions, relieve the engine's crankcase of
pressure and vapors, and reduce the formation of oil sludge.
Technician A says the crankshaft position sensor can be a Hall-effect switch.
Technician B says the crankshaft position sensor can be a magnetic pulse generator.
,Who is correct? - ANSWERSBoth A and B.
Technician A says both the fuel injector and spark plug are turned off when a cylinder is deactivated
on a variable displacement engine. Technician B says the spark plug may foul if is allowed to become
too cool during cylinder deactivation. Who is correct? - ANSWERSTechnician B.
Technician A says that ion-sensing ignition systems are based on the coil on plug system.
Technician B say that the ion-sensing ignition system uses the spark plug itself as a sensor. Who is
correct? - ANSWERSBoth A and B.
The acceptable amount of ethanol mixed with conventional gasoline is: - ANSWERSUp to 10%.
True or False:
Long term fuel trim will change in an attempt to keep short term fuel trim near 0. - ANSWERSTrue
Short-term fuel trim (STFT) adds or subtracts fuel to correct for: - ANSWERSSmall or temporary
changes and changes in the O2 sensor signal.
Which of the following is false concerning variable valve timing engines? - ANSWERSThey utilize the
camshaft (CMP) and crankshaft (CKP) sensors to determine the amount of advance or retard.
Technician A says Mode 5 contains the tests for non-continuously monitored systems. Technician B
says Mode 6 contains the oxygen sensor monitoring tests. Who is correct? - ANSWERSNeither A or B.
Which of the following is a pre-combustion emission control? - ANSWERSEVAP
If the pressure is increased on a gas in an enclosed container, the temperature of the gas will: -
ANSWERSIncrease.
Oxides of nitrogen (NOx) are formed when combustion temperatures reach more than: -
ANSWERS2,500 degrees F.
,The output voltage of a downstream O2 sensor is fluctuating when the engine is at operating
temperature. Technician A says the catalytic converter is working efficiently. Technician B says the
O2 sensor may need to be replaced. Who is correct? - ANSWERSNeither A and B.
Spark plugs are being discussed: Technician A says iridium spark plugs should not have the gap
checked by the technician. Technician B says platinum spark plugs should not have the electrode
filed. Who is correct? - ANSWERSTechnician B.
Technician A says a rich air-fuel mixture may be the result of higher-than-normal fuel pressure.
Technician B says higher-than-normal fuel pressure causes a lean air-fuel ratio. Who is correct? -
ANSWERSTechnician A.
Technician A say canister purging occurs only when conditions are correct.
technician B says modern purge valves are computer controlled. Who is correct? - ANSWERSBoth A
and B.
While discussing direct fuel injection (DFI), Technician A says the DFI injector may require a special
tool to remove it from the cylinder head. Technician B says the DFI high-pressure fuel line from the
high-pressure pump to the fuel rail can be reused only twice before replacement. Who is correct? -
ANSWERSTechnician A.
A V6 engine requires how many spark events (spark plug firings) per crankshaft revolution? -
ANSWERS3.
Excessive CO emissions may be caused by: - ANSWERSRich air-fuel mixtures.
Technician A says a speed density EFI system is one in which the computer calculates the amount of
air entering the engine. Technician B says that to determine the air entering the engine in a speed-
density system, the computer uses the TPS and ECT signals. Who is correct? - ANSWERSTechnician A.
Twenty inches of vacuum would be equivalent to how much pressure absolute? - ANSWERS5 psia.
A waste spark ignition system equipped vehicle has a no-spark condition. Technician A says the
crankshaft position sensor may be defective. Technician B says the ignition module may be defective.
Who is correct? - ANSWERSBoth A and B.
, True or False:
If dwell time is to short, the coil and module can overheat. - ANSWERSTrue
Technician A says a quad driver has four independently controllable outputs. Technician B says some
output driver modules may control up seven independent outputs. Who is correct? - ANSWERSBoth
A and B.
While discussing primary and secondary ignition circuits, Technician A says that the primary circuit
controls the secondary circuit.
Technician B says that the primary circuit also controls ignition timing in the secondary circuit. Who
is correct? - ANSWERSBoth A and B.
Variable cam timing is used to allow high overlap at: - ANSWERSHigh RPM.
To help isolate a clogged or dirty injector: - ANSWERSPerform an injector balance test.
The signal that alerts the misfire monitor that a misfire may be occurring is provided by the: -
ANSWERSThe crankshaft position sensor.
All CAN protocol messages contain all of the following information except: - ANSWERSOther
modules acknowledge the message.
Technician A says any induction air leak after the MAF sensor can cause a poor running condition.
Technician B says an air leak after the MAF sensor results in un-metered air. Who is correct? -
ANSWERSBoth A and B.
True or False:
Feedback circuits only refer to O2 sensor information. - ANSWERSFalse.
Which of the following is not part of comprehensive component monitoring? - ANSWERSCatalyst
Efficiency.
The ignition switch, primary coil winding, and module are all components of: - ANSWERSThe primary
ignition circuit.
Electrical and Engine
Performance
Magnetic pulse generators are commonly used to send data to the computer about: - ANSWERSThe
speed of the monitored component.
Technician A says pulse width modulation (PWM) is measured in a length of time, not a percentage
of a cycle. Technician B says that the cooling fan relay is usually controlled by the PCM through
PWM. Who is correct? - ANSWERSBoth A and B
When the pressure in the intake manifold increases the fuel pressure regulator on a port fuel
injection system: - ANSWERSIncreases fuel pressure.
Technician A says a P0300 is considered a generic DTC.
Technician B says a P1300 is considered a manufacturer specific DTC. - ANSWERSBoth A and B
The vent valve in an evaporative emissions system may be: - ANSWERSOpened to allow fresh air
through the charcoal canister and closed with the purge valve open while the PCM monitors the fuel
tank pressure sensor for vacuum.
Technician A says the computer may activate a circuit by completing the path to ground. Technician
B says the computer may activate a circuit by completing the path to power. Who is correct? -
ANSWERSBoth A and B.
Technician A states that non-contact type hall-effect sensors wear out very quickly.
Technician B states that some throttle position sensors are non-contact. - ANSWERSTechnician B
only.
The purpose of the PCV system is to: - ANSWERSControl emissions, relieve the engine's crankcase of
pressure and vapors, and reduce the formation of oil sludge.
Technician A says the crankshaft position sensor can be a Hall-effect switch.
Technician B says the crankshaft position sensor can be a magnetic pulse generator.
,Who is correct? - ANSWERSBoth A and B.
Technician A says both the fuel injector and spark plug are turned off when a cylinder is deactivated
on a variable displacement engine. Technician B says the spark plug may foul if is allowed to become
too cool during cylinder deactivation. Who is correct? - ANSWERSTechnician B.
Technician A says that ion-sensing ignition systems are based on the coil on plug system.
Technician B say that the ion-sensing ignition system uses the spark plug itself as a sensor. Who is
correct? - ANSWERSBoth A and B.
The acceptable amount of ethanol mixed with conventional gasoline is: - ANSWERSUp to 10%.
True or False:
Long term fuel trim will change in an attempt to keep short term fuel trim near 0. - ANSWERSTrue
Short-term fuel trim (STFT) adds or subtracts fuel to correct for: - ANSWERSSmall or temporary
changes and changes in the O2 sensor signal.
Which of the following is false concerning variable valve timing engines? - ANSWERSThey utilize the
camshaft (CMP) and crankshaft (CKP) sensors to determine the amount of advance or retard.
Technician A says Mode 5 contains the tests for non-continuously monitored systems. Technician B
says Mode 6 contains the oxygen sensor monitoring tests. Who is correct? - ANSWERSNeither A or B.
Which of the following is a pre-combustion emission control? - ANSWERSEVAP
If the pressure is increased on a gas in an enclosed container, the temperature of the gas will: -
ANSWERSIncrease.
Oxides of nitrogen (NOx) are formed when combustion temperatures reach more than: -
ANSWERS2,500 degrees F.
,The output voltage of a downstream O2 sensor is fluctuating when the engine is at operating
temperature. Technician A says the catalytic converter is working efficiently. Technician B says the
O2 sensor may need to be replaced. Who is correct? - ANSWERSNeither A and B.
Spark plugs are being discussed: Technician A says iridium spark plugs should not have the gap
checked by the technician. Technician B says platinum spark plugs should not have the electrode
filed. Who is correct? - ANSWERSTechnician B.
Technician A says a rich air-fuel mixture may be the result of higher-than-normal fuel pressure.
Technician B says higher-than-normal fuel pressure causes a lean air-fuel ratio. Who is correct? -
ANSWERSTechnician A.
Technician A say canister purging occurs only when conditions are correct.
technician B says modern purge valves are computer controlled. Who is correct? - ANSWERSBoth A
and B.
While discussing direct fuel injection (DFI), Technician A says the DFI injector may require a special
tool to remove it from the cylinder head. Technician B says the DFI high-pressure fuel line from the
high-pressure pump to the fuel rail can be reused only twice before replacement. Who is correct? -
ANSWERSTechnician A.
A V6 engine requires how many spark events (spark plug firings) per crankshaft revolution? -
ANSWERS3.
Excessive CO emissions may be caused by: - ANSWERSRich air-fuel mixtures.
Technician A says a speed density EFI system is one in which the computer calculates the amount of
air entering the engine. Technician B says that to determine the air entering the engine in a speed-
density system, the computer uses the TPS and ECT signals. Who is correct? - ANSWERSTechnician A.
Twenty inches of vacuum would be equivalent to how much pressure absolute? - ANSWERS5 psia.
A waste spark ignition system equipped vehicle has a no-spark condition. Technician A says the
crankshaft position sensor may be defective. Technician B says the ignition module may be defective.
Who is correct? - ANSWERSBoth A and B.
, True or False:
If dwell time is to short, the coil and module can overheat. - ANSWERSTrue
Technician A says a quad driver has four independently controllable outputs. Technician B says some
output driver modules may control up seven independent outputs. Who is correct? - ANSWERSBoth
A and B.
While discussing primary and secondary ignition circuits, Technician A says that the primary circuit
controls the secondary circuit.
Technician B says that the primary circuit also controls ignition timing in the secondary circuit. Who
is correct? - ANSWERSBoth A and B.
Variable cam timing is used to allow high overlap at: - ANSWERSHigh RPM.
To help isolate a clogged or dirty injector: - ANSWERSPerform an injector balance test.
The signal that alerts the misfire monitor that a misfire may be occurring is provided by the: -
ANSWERSThe crankshaft position sensor.
All CAN protocol messages contain all of the following information except: - ANSWERSOther
modules acknowledge the message.
Technician A says any induction air leak after the MAF sensor can cause a poor running condition.
Technician B says an air leak after the MAF sensor results in un-metered air. Who is correct? -
ANSWERSBoth A and B.
True or False:
Feedback circuits only refer to O2 sensor information. - ANSWERSFalse.
Which of the following is not part of comprehensive component monitoring? - ANSWERSCatalyst
Efficiency.
The ignition switch, primary coil winding, and module are all components of: - ANSWERSThe primary
ignition circuit.
