AUTOMOTIVE ENGINE PERFORMANCE POST TEST
REVIEW
Magnetic pulse generators are commonly used to send data to the computer about: -
Answers - 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? - Answers - Both A and B
When the pressure in the intake manifold increases the fuel pressure regulator on a port
fuel injection system: - Answers - Increases fuel pressure.
Technician A says a P0300 is considered a generic DTC.
Technician B says a P1300 is considered a manufacturer specific DTC. - Answers -
Both A and B
The vent valve in an evaporative emissions system may be: - Answers - 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? - Answers - 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. - Answers -
Technician B only.
The purpose of the PCV system is to: - Answers - 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? - Answers - 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? -
Answers - 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? - Answers - Both A and B.
The acceptable amount of ethanol mixed with conventional gasoline is: - Answers - Up
to 10%.
True or False:
Long term fuel trim will change in an attempt to keep short term fuel trim near 0. -
Answers - True
Short-term fuel trim (STFT) adds or subtracts fuel to correct for: - Answers - Small or
temporary changes and changes in the O2 sensor signal.
Which of the following is false concerning variable valve timing engines? - Answers -
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? - Answers - Neither A or B.
Which of the following is a pre-combustion emission control? - Answers - EVAP
If the pressure is increased on a gas in an enclosed container, the temperature of the
gas will: - Answers - Increase.
Oxides of nitrogen (NOx) are formed when combustion temperatures reach more than: -
Answers - 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? - Answers -
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? - Answers - 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? - Answers - 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? -
Answers - Both A and B.
REVIEW
Magnetic pulse generators are commonly used to send data to the computer about: -
Answers - 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? - Answers - Both A and B
When the pressure in the intake manifold increases the fuel pressure regulator on a port
fuel injection system: - Answers - Increases fuel pressure.
Technician A says a P0300 is considered a generic DTC.
Technician B says a P1300 is considered a manufacturer specific DTC. - Answers -
Both A and B
The vent valve in an evaporative emissions system may be: - Answers - 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? - Answers - 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. - Answers -
Technician B only.
The purpose of the PCV system is to: - Answers - 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? - Answers - 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? -
Answers - 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? - Answers - Both A and B.
The acceptable amount of ethanol mixed with conventional gasoline is: - Answers - Up
to 10%.
True or False:
Long term fuel trim will change in an attempt to keep short term fuel trim near 0. -
Answers - True
Short-term fuel trim (STFT) adds or subtracts fuel to correct for: - Answers - Small or
temporary changes and changes in the O2 sensor signal.
Which of the following is false concerning variable valve timing engines? - Answers -
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? - Answers - Neither A or B.
Which of the following is a pre-combustion emission control? - Answers - EVAP
If the pressure is increased on a gas in an enclosed container, the temperature of the
gas will: - Answers - Increase.
Oxides of nitrogen (NOx) are formed when combustion temperatures reach more than: -
Answers - 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? - Answers -
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? - Answers - 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? - Answers - 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? -
Answers - Both A and B.
