Michigan Secretary Of State
2026/2027/2028 Testing Cycle
100 Questions & Answers | Verified Rationales
Guaranteed Pass | Graded A+
,SECTION 1: COMPUTER CONTROL & SENSOR BASICS (24 Questions)
Q1: In automotive computers, this memory contains information that tailors the computer to the
vehicle.
A. Programmable Read Only Memory (PROM)
B. Controllable Access Memory (CAM)
C. Random Access Memory (RAM)
D. None of the above
Answer: A
Rationale: PROM (Programmable Read Only Memory) contains the calibration information
specific to the vehicle, including fuel curves, spark advance tables, and transmission shift points.
RAM is volatile memory used for temporary data storage.
Q2: A vehicle has a code set for the oxygen sensor. Technician A says the oxygen sensor
monitors oxygen content in the exhaust stream. Technician B says the oxygen sensor monitors
oxygen content in the intake air. Who is correct?
A. Technician A only
B. Technician B only
C. Both Technician A and Technician B
D. Neither Technician A nor Technician B
Answer: A
Rationale: The oxygen sensor (O2 sensor) is located in the exhaust stream and monitors the
oxygen content of the exhaust gases to determine whether the air-fuel mixture is rich or lean. The
mass airflow sensor and manifold absolute pressure sensor monitor intake air.
Q3: The PCM is operating in closed loop. Technician A says the PCM is using oxygen sensor
feedback to adjust fuel delivery. Technician B says the PCM is ignoring oxygen sensor feedback.
Who is correct?
A. Technician A only
B. Technician B only
C. Both Technician A and Technician B
D. Neither Technician A nor Technician B
Answer: A
,Rationale: In closed loop operation, the PCM uses oxygen sensor feedback to continuously
adjust the air-fuel mixture to maintain stoichiometric balance (14.7:1). In open loop, the PCM
ignores O2 sensor feedback and uses pre-programmed values.
Q4: A scan tool is being used to check oxygen sensor activity. The O2 sensor voltage is
fluctuating rapidly between 0.1 and 0.9 volts. What does this indicate?
A. The O2 sensor is functioning correctly
B. The O2 sensor is stuck lean
C. The O2 sensor is stuck rich
D. The O2 sensor is contaminated
Answer: A
Rationale: A properly functioning oxygen sensor should rapidly fluctuate between approximately
0.1 and 0.9 volts as the PCM continuously adjusts the air-fuel mixture. A stuck reading indicates
a faulty sensor or circuit.
Q5: The purpose of a knock sensor is to:
A. Detect engine knock and retard ignition timing
B. Detect engine knock and advance ignition timing
C. Measure intake air temperature
D. Monitor exhaust gas recirculation flow
Answer: A
Rationale: The knock sensor detects abnormal combustion (detonation/spark knock) and sends a
signal to the PCM, which retards ignition timing to prevent engine damage.
Q6: A technician is diagnosing a vehicle with a P0335 crankshaft position sensor code.
Technician A says a faulty crank sensor can cause a no-start condition. Technician B says a faulty
crank sensor can cause a misfire. Who is correct?
A. Technician A only
B. Technician B only
C. Both Technician A and Technician B
D. Neither Technician A nor Technician B
Answer: C
, Rationale: The crankshaft position sensor provides the PCM with engine speed and position data.
A faulty sensor can cause a no-start (no spark/no fuel injection) or cause misfires and poor
performance if the signal is intermittent.
Q7: The throttle position sensor (TPS) provides the PCM with information about:
A. Engine speed
B. Throttle blade angle
C. Intake air volume
D. Exhaust oxygen content
Answer: B
Rationale: The TPS is mounted on the throttle body and sends a voltage signal to the PCM that
corresponds to the throttle blade angle, indicating driver demand for acceleration or deceleration.
Q8: A vehicle has a "no start" condition with no spark and no injector pulse. Technician A says a
faulty crankshaft position sensor could be the cause. Technician B says a faulty camshaft position
sensor could be the cause. Who is correct?
A. Technician A only
B. Technician B only
C. Both Technician A and Technician B
D. Neither Technician A nor Technician B
Answer: A
Rationale: A faulty crankshaft position sensor is a primary cause of no spark and no injector
pulse because the PCM relies on the crank signal to determine engine position and trigger
ignition and injection events.
Q9: The PCM uses information from the manifold absolute pressure (MAP) sensor to determine:
A. Engine load
B. Throttle position
C. Exhaust oxygen content
D. Fuel tank pressure
Answer: A
Rationale: The MAP sensor measures intake manifold vacuum/pressure, which the PCM uses to
calculate engine load and adjust fuel delivery and ignition timing accordingly.
2026/2027/2028 Testing Cycle
100 Questions & Answers | Verified Rationales
Guaranteed Pass | Graded A+
,SECTION 1: COMPUTER CONTROL & SENSOR BASICS (24 Questions)
Q1: In automotive computers, this memory contains information that tailors the computer to the
vehicle.
A. Programmable Read Only Memory (PROM)
B. Controllable Access Memory (CAM)
C. Random Access Memory (RAM)
D. None of the above
Answer: A
Rationale: PROM (Programmable Read Only Memory) contains the calibration information
specific to the vehicle, including fuel curves, spark advance tables, and transmission shift points.
RAM is volatile memory used for temporary data storage.
Q2: A vehicle has a code set for the oxygen sensor. Technician A says the oxygen sensor
monitors oxygen content in the exhaust stream. Technician B says the oxygen sensor monitors
oxygen content in the intake air. Who is correct?
A. Technician A only
B. Technician B only
C. Both Technician A and Technician B
D. Neither Technician A nor Technician B
Answer: A
Rationale: The oxygen sensor (O2 sensor) is located in the exhaust stream and monitors the
oxygen content of the exhaust gases to determine whether the air-fuel mixture is rich or lean. The
mass airflow sensor and manifold absolute pressure sensor monitor intake air.
Q3: The PCM is operating in closed loop. Technician A says the PCM is using oxygen sensor
feedback to adjust fuel delivery. Technician B says the PCM is ignoring oxygen sensor feedback.
Who is correct?
A. Technician A only
B. Technician B only
C. Both Technician A and Technician B
D. Neither Technician A nor Technician B
Answer: A
,Rationale: In closed loop operation, the PCM uses oxygen sensor feedback to continuously
adjust the air-fuel mixture to maintain stoichiometric balance (14.7:1). In open loop, the PCM
ignores O2 sensor feedback and uses pre-programmed values.
Q4: A scan tool is being used to check oxygen sensor activity. The O2 sensor voltage is
fluctuating rapidly between 0.1 and 0.9 volts. What does this indicate?
A. The O2 sensor is functioning correctly
B. The O2 sensor is stuck lean
C. The O2 sensor is stuck rich
D. The O2 sensor is contaminated
Answer: A
Rationale: A properly functioning oxygen sensor should rapidly fluctuate between approximately
0.1 and 0.9 volts as the PCM continuously adjusts the air-fuel mixture. A stuck reading indicates
a faulty sensor or circuit.
Q5: The purpose of a knock sensor is to:
A. Detect engine knock and retard ignition timing
B. Detect engine knock and advance ignition timing
C. Measure intake air temperature
D. Monitor exhaust gas recirculation flow
Answer: A
Rationale: The knock sensor detects abnormal combustion (detonation/spark knock) and sends a
signal to the PCM, which retards ignition timing to prevent engine damage.
Q6: A technician is diagnosing a vehicle with a P0335 crankshaft position sensor code.
Technician A says a faulty crank sensor can cause a no-start condition. Technician B says a faulty
crank sensor can cause a misfire. Who is correct?
A. Technician A only
B. Technician B only
C. Both Technician A and Technician B
D. Neither Technician A nor Technician B
Answer: C
, Rationale: The crankshaft position sensor provides the PCM with engine speed and position data.
A faulty sensor can cause a no-start (no spark/no fuel injection) or cause misfires and poor
performance if the signal is intermittent.
Q7: The throttle position sensor (TPS) provides the PCM with information about:
A. Engine speed
B. Throttle blade angle
C. Intake air volume
D. Exhaust oxygen content
Answer: B
Rationale: The TPS is mounted on the throttle body and sends a voltage signal to the PCM that
corresponds to the throttle blade angle, indicating driver demand for acceleration or deceleration.
Q8: A vehicle has a "no start" condition with no spark and no injector pulse. Technician A says a
faulty crankshaft position sensor could be the cause. Technician B says a faulty camshaft position
sensor could be the cause. Who is correct?
A. Technician A only
B. Technician B only
C. Both Technician A and Technician B
D. Neither Technician A nor Technician B
Answer: A
Rationale: A faulty crankshaft position sensor is a primary cause of no spark and no injector
pulse because the PCM relies on the crank signal to determine engine position and trigger
ignition and injection events.
Q9: The PCM uses information from the manifold absolute pressure (MAP) sensor to determine:
A. Engine load
B. Throttle position
C. Exhaust oxygen content
D. Fuel tank pressure
Answer: A
Rationale: The MAP sensor measures intake manifold vacuum/pressure, which the PCM uses to
calculate engine load and adjust fuel delivery and ignition timing accordingly.
