Automotive Engine Performance Post Test Review
2023;Modules 1 through 5 for AEP Review with complete
solution
Magnetic pulse generators are commonly used to send data to the computer about:
The 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?
Both A and B
When the pressure in the intake manifold increases the fuel pressure regulator on a port
fuel injection system:
Increases fuel pressure.
Technician A says a P0300 is considered a generic DTC.
Technician B says a P1300 is considered a manufacturer specific DTC.
Both A and B
The vent valve in an evaporative emissions system may be:
Opened 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?
Both 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.
Technician B only.
The purpose of the PCV system is to:
Control 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?
Both 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?
Technician 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?
Both A and B.
The acceptable amount of ethanol mixed with conventional gasoline is:
Up to 10%.
, True or False:
Long term fuel trim will change in an attempt to keep short term fuel trim near 0.
True
Short-term fuel trim (STFT) adds or subtracts fuel to correct for:
Small or temporary changes and changes in the O2 sensor signal.
Which of the following is false concerning variable valve timing engines?
They 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?
Neither A or B.
Which of the following is a pre-combustion emission control?
EVAP
If the pressure is increased on a gas in an enclosed container, the temperature of the
gas will:
Increase.
Oxides of nitrogen (NOx) are formed when combustion temperatures reach more than:
2,500 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?
Neither 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?
Technician 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?
Technician A.
Technician A say canister purging occurs only when conditions are correct.
technician B says modern purge valves are computer controlled. Who is correct?
Both 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?
Technician A.
A V6 engine requires how many spark events (spark plug firings) per crankshaft
revolution?
3.
Excessive CO emissions may be caused by:
Rich 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
2023;Modules 1 through 5 for AEP Review with complete
solution
Magnetic pulse generators are commonly used to send data to the computer about:
The 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?
Both A and B
When the pressure in the intake manifold increases the fuel pressure regulator on a port
fuel injection system:
Increases fuel pressure.
Technician A says a P0300 is considered a generic DTC.
Technician B says a P1300 is considered a manufacturer specific DTC.
Both A and B
The vent valve in an evaporative emissions system may be:
Opened 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?
Both 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.
Technician B only.
The purpose of the PCV system is to:
Control 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?
Both 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?
Technician 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?
Both A and B.
The acceptable amount of ethanol mixed with conventional gasoline is:
Up to 10%.
, True or False:
Long term fuel trim will change in an attempt to keep short term fuel trim near 0.
True
Short-term fuel trim (STFT) adds or subtracts fuel to correct for:
Small or temporary changes and changes in the O2 sensor signal.
Which of the following is false concerning variable valve timing engines?
They 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?
Neither A or B.
Which of the following is a pre-combustion emission control?
EVAP
If the pressure is increased on a gas in an enclosed container, the temperature of the
gas will:
Increase.
Oxides of nitrogen (NOx) are formed when combustion temperatures reach more than:
2,500 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?
Neither 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?
Technician 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?
Technician A.
Technician A say canister purging occurs only when conditions are correct.
technician B says modern purge valves are computer controlled. Who is correct?
Both 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?
Technician A.
A V6 engine requires how many spark events (spark plug firings) per crankshaft
revolution?
3.
Excessive CO emissions may be caused by:
Rich 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
