Automotive Engine Performance final exam
UPDATED ACTUAL Questions and
CORRECT Answers
In a GDI system (gasoline direct injection) the injector sprays fuel into the ______. - CORRECT
ANSWER - d.
cylinders (combustion chamber)
Which of the following is NOT an advantage of an electronic spark control system? - CORRECT
ANSWER - b.
It allows lower compression ratio engines to be as efficient as higher compression ratio engines
Waste spark EI systems are being discussed. Technician A says a high-resistance spark plug won't affect
the firing of its companion spark plug. Technician B says improper spark plug torque can't cause an
engine misfire. Who is correct? - CORRECT ANSWER - d. neither A nor B
What is an advantage of EI ignition? - CORRECT ANSWER - d. All of the answers are correct.
Technician A says a plug with a V-notch ground electrode will have two electric arcs jumping across the
spark plug gap each time the spark plug fires. Technician B says a spark plug gap that is too wide requires
higher voltage to jump the gap, which can cause a misfire. Who is correct? - CORRECT
ANSWER - b. B only
OBD II technology is being discussed. Technician A says the OBD II system has the ability to store a
freeze frame (snapshot) of the operating conditions that existed when the fault occurred. Technician B
says vehicle identification must be transmitted automatically to the scan tool. Who is correct? -
CORRECT ANSWER - c. Both A and B
A vehicle with a DTC for an engine coolant temperature out of range code is being tested.The serial data
stream shows the coolant temperature to be 198 degrees Fahrenheit. When the technician tests the
resistance between the ETC terminals, he finds infinite resistance. The specifications call for 20 to 40
ohms at 200 degrees Fahrenheit. After the ECT is replaced and the code is erased, the system runs
normally and the code and MIL illumination do not reoccur. How is this possible? - CORRECT
ANSWER - d.
,When the ECT failed, the PCM substituted a nominal ECT value that allowed the engine to run in limp
home mode; the substituted value was displayed by the scan tool
Two technicians are discussing OBD-II monitor readiness status. Technician A says that the vehicle must
be driven through a drive cycle that includes several minutes of idle, low-speed cruise, medium-speed
cruise, and deceleration before all monitors can be performed. Technician B says all monitors can be
performed in five minutes of fast idling. Who is correct? - CORRECT ANSWER - a. A only
The two types of ignition systems are EI (electronic ignition) and ______. - CORRECT
ANSWER - b. DI (distributor ignition)
Two technicians are discussing testing switch type sensors. Technician A uses an ohmmeter. Technician
B uses a voltmeter. Who is correct? - CORRECT ANSWER - c. both A and B
In EI systems using one ignition coil for every two cylinders, Technician A says two plugs fire at the
same time, with one wasting the spark on the exhaust stroke. Technician B says one plug fires in the
normal direction and the other in reversed polarity. Who is correct? - CORRECT ANSWER - c.
both A and B
A vehicle towed into the shop will crank but won't start. A quick check under the hood reveals that the
spark plugs are not firing and the injectors are not receiving a pulse from the PCM. The technician notices
that the MIL light does not come on when the key is turned to the run position. What should he do next? -
CORRECT ANSWER - a.
Check the PCM's fuses, power wires, and ground wires
Ignition timing is being discussed. Technician A says when the engine idle speed moves away from the
desired idle speed, the PCM will adjust the timing to stabilize the engine speed. Technician B says when a
knock is detected, the PCM retards the timing in fixed steps until the knock disappears. Who is correct? -
CORRECT ANSWER - c. both A and B
Besides the tailpipe, hydrocarbons (HC) can also be emitted from the _______. - CORRECT
ANSWER - d. all of the answers are correct.
While discussing an ignition problem displayed on a scope primary ignition pattern, Technician A says a
worn distributor drive gear can cause an erratic transistor ON signal. Technician Bsays if there are erratic
, voltage spikes at the transistor ON signal, the ignition module may be faulty. Who is correct? -
CORRECT ANSWER - c. Both a and B
Oxygen sensor monitors are being discussed. Technician A says the system monitors the sensor response
time as the system cycles lean-rich-lean. Technician B says that at certain times the monitor varies the
fuel delivery and checks for heated oxygen sensor response. Who is correct? - CORRECT
ANSWER - c. Both A and B
Possible causes for a no-start condition on a coil-over-plug EI engine are being discussed. Technician A
says a faulty crankshaft sensor may prevent the engine from starting. Technician B says a shorted ignition
coil may be the cause. Who is correct? - CORRECT ANSWER - a. A only
The hex size (socket size) used for tightening and loosing the spark plugs is either 5/8 in. or ______. -
CORRECT ANSWER - d. 13/16 in.
Reach, heat range, and air gap are all characteristics that affect the performance of which ignition system
component? - CORRECT ANSWER - c. spark plugs
Which of the following is not a PCM output? - CORRECT ANSWER - b. thermostats
EI systems are being discussed. Technician A says a waste spark system has one coil per cylinder.
Technician B says a coil-on-plug system uses a double-ended coil. Who is correct? - CORRECT
ANSWER - c. both A and B
Which of the following tools cannot be used to test an oxygen sensor? - CORRECT ANSWER - b.
analog voltmeter
Which of the following is not a type of electronic ignition system? - CORRECT ANSWER - a.
DI (distributor ignition)
Coil-over-plug ignition systems are being discussed, Technician Asays COP coils have less time between
each firing cycle, which increases the heat in the coil and can cause premature failure. Technician B says
the COP system allows the ignition timing for each cylinder to be individually changed for maximum
UPDATED ACTUAL Questions and
CORRECT Answers
In a GDI system (gasoline direct injection) the injector sprays fuel into the ______. - CORRECT
ANSWER - d.
cylinders (combustion chamber)
Which of the following is NOT an advantage of an electronic spark control system? - CORRECT
ANSWER - b.
It allows lower compression ratio engines to be as efficient as higher compression ratio engines
Waste spark EI systems are being discussed. Technician A says a high-resistance spark plug won't affect
the firing of its companion spark plug. Technician B says improper spark plug torque can't cause an
engine misfire. Who is correct? - CORRECT ANSWER - d. neither A nor B
What is an advantage of EI ignition? - CORRECT ANSWER - d. All of the answers are correct.
Technician A says a plug with a V-notch ground electrode will have two electric arcs jumping across the
spark plug gap each time the spark plug fires. Technician B says a spark plug gap that is too wide requires
higher voltage to jump the gap, which can cause a misfire. Who is correct? - CORRECT
ANSWER - b. B only
OBD II technology is being discussed. Technician A says the OBD II system has the ability to store a
freeze frame (snapshot) of the operating conditions that existed when the fault occurred. Technician B
says vehicle identification must be transmitted automatically to the scan tool. Who is correct? -
CORRECT ANSWER - c. Both A and B
A vehicle with a DTC for an engine coolant temperature out of range code is being tested.The serial data
stream shows the coolant temperature to be 198 degrees Fahrenheit. When the technician tests the
resistance between the ETC terminals, he finds infinite resistance. The specifications call for 20 to 40
ohms at 200 degrees Fahrenheit. After the ECT is replaced and the code is erased, the system runs
normally and the code and MIL illumination do not reoccur. How is this possible? - CORRECT
ANSWER - d.
,When the ECT failed, the PCM substituted a nominal ECT value that allowed the engine to run in limp
home mode; the substituted value was displayed by the scan tool
Two technicians are discussing OBD-II monitor readiness status. Technician A says that the vehicle must
be driven through a drive cycle that includes several minutes of idle, low-speed cruise, medium-speed
cruise, and deceleration before all monitors can be performed. Technician B says all monitors can be
performed in five minutes of fast idling. Who is correct? - CORRECT ANSWER - a. A only
The two types of ignition systems are EI (electronic ignition) and ______. - CORRECT
ANSWER - b. DI (distributor ignition)
Two technicians are discussing testing switch type sensors. Technician A uses an ohmmeter. Technician
B uses a voltmeter. Who is correct? - CORRECT ANSWER - c. both A and B
In EI systems using one ignition coil for every two cylinders, Technician A says two plugs fire at the
same time, with one wasting the spark on the exhaust stroke. Technician B says one plug fires in the
normal direction and the other in reversed polarity. Who is correct? - CORRECT ANSWER - c.
both A and B
A vehicle towed into the shop will crank but won't start. A quick check under the hood reveals that the
spark plugs are not firing and the injectors are not receiving a pulse from the PCM. The technician notices
that the MIL light does not come on when the key is turned to the run position. What should he do next? -
CORRECT ANSWER - a.
Check the PCM's fuses, power wires, and ground wires
Ignition timing is being discussed. Technician A says when the engine idle speed moves away from the
desired idle speed, the PCM will adjust the timing to stabilize the engine speed. Technician B says when a
knock is detected, the PCM retards the timing in fixed steps until the knock disappears. Who is correct? -
CORRECT ANSWER - c. both A and B
Besides the tailpipe, hydrocarbons (HC) can also be emitted from the _______. - CORRECT
ANSWER - d. all of the answers are correct.
While discussing an ignition problem displayed on a scope primary ignition pattern, Technician A says a
worn distributor drive gear can cause an erratic transistor ON signal. Technician Bsays if there are erratic
, voltage spikes at the transistor ON signal, the ignition module may be faulty. Who is correct? -
CORRECT ANSWER - c. Both a and B
Oxygen sensor monitors are being discussed. Technician A says the system monitors the sensor response
time as the system cycles lean-rich-lean. Technician B says that at certain times the monitor varies the
fuel delivery and checks for heated oxygen sensor response. Who is correct? - CORRECT
ANSWER - c. Both A and B
Possible causes for a no-start condition on a coil-over-plug EI engine are being discussed. Technician A
says a faulty crankshaft sensor may prevent the engine from starting. Technician B says a shorted ignition
coil may be the cause. Who is correct? - CORRECT ANSWER - a. A only
The hex size (socket size) used for tightening and loosing the spark plugs is either 5/8 in. or ______. -
CORRECT ANSWER - d. 13/16 in.
Reach, heat range, and air gap are all characteristics that affect the performance of which ignition system
component? - CORRECT ANSWER - c. spark plugs
Which of the following is not a PCM output? - CORRECT ANSWER - b. thermostats
EI systems are being discussed. Technician A says a waste spark system has one coil per cylinder.
Technician B says a coil-on-plug system uses a double-ended coil. Who is correct? - CORRECT
ANSWER - c. both A and B
Which of the following tools cannot be used to test an oxygen sensor? - CORRECT ANSWER - b.
analog voltmeter
Which of the following is not a type of electronic ignition system? - CORRECT ANSWER - a.
DI (distributor ignition)
Coil-over-plug ignition systems are being discussed, Technician Asays COP coils have less time between
each firing cycle, which increases the heat in the coil and can cause premature failure. Technician B says
the COP system allows the ignition timing for each cylinder to be individually changed for maximum
