Michigan Secretary Of State
2026/2027/2028 Testing Cycle
100 Questions & Answers | Verified Rationales
Guaranteed Pass | Graded A+
,SECTION 1: ELECTRONIC CONTROLS (29 Questions)
Q1: A technician is checking the oxygen sensor during closed loop operation. The voltage is
fluctuating between 0.45 and 0.50 volts and does not vary. What does this indicate?
A. The sensor is functioning correctly
B. The sensor is sluggish and probably faulty
C. The sensor is stuck lean
D. The sensor is stuck rich
Answer: B
Rationale: A properly functioning O2 sensor should rapidly fluctuate between 0.1 and 0.9 volts.
A reading that stays near 0.45–0.50 volts (midpoint) with little variation indicates a sluggish or
contaminated sensor that is not responding to changes in exhaust oxygen content.
Q2: Technician A says the PCM uses the manifold absolute pressure (MAP) sensor to measure
engine load. Technician B says the PCM uses the MAP sensor to calculate fuel delivery. 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 MAP sensor measures intake manifold pressure/vacuum, which the PCM uses to
determine engine load and calculate the proper fuel delivery and ignition timing.
Q3: A vehicle has a P0101 code set. Technician A says this indicates a mass airflow sensor
performance problem. Technician B says this indicates a manifold absolute pressure sensor
problem. 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: P0101 is defined as "Mass Air Flow Circuit Range/Performance." The code
specifically relates to the MAF sensor and its circuit, not the MAP sensor.
Q4: A technician is testing a throttle position sensor. The voltage reading jumps erratically when
the throttle is slowly opened. What does this indicate?
A. The TPS is functioning correctly
B. The TPS has a dead spot or erratic signal
C. The PCM is faulty
D. The throttle cable is binding
Answer: B
Rationale: An erratic or jumpy TPS signal indicates a worn resistive element or dirty contacts
inside the sensor. The TPS should be replaced.
Q5: Technician A says a Hall-effect sensor produces a digital square wave signal. Technician B
says a variable reluctance sensor produces an analog AC voltage signal. 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: Hall-effect sensors produce a digital square wave (on/off) signal, while variable
reluctance sensors produce an analog AC voltage waveform whose amplitude and frequency
increase with speed.
Q6: A vehicle has a P0335 code set. Technician A says this indicates a crankshaft position sensor
circuit malfunction. Technician B says the engine may have a no-start condition. 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: P0335 is the crankshaft position sensor circuit code. When this sensor fails, the PCM
has no engine position reference, resulting in no spark and no fuel injector pulse — a no-start
condition.
Q7: Technician A says the PCM uses the engine coolant temperature (ECT) sensor to determine
fuel enrichment during cold start. Technician B says the PCM uses the intake air temperature
(IAT) sensor to determine fuel enrichment during cold start. 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: Both sensors provide critical input during cold start. The ECT tells the PCM the
engine is cold and needs enrichment, while the IAT helps the PCM calculate air density for
proper fuel delivery.
Q8: A technician is checking the reference voltage at the throttle position sensor. The
specification is 5.0 volts. The meter reads 5.0 volts. What should the technician do next?
A. Replace the TPS
B. Check the signal voltage at closed throttle and wide open throttle
C. Replace the PCM
D. Adjust the throttle cable
Answer: B
Rationale: With correct reference voltage confirmed, the next step is to check the TPS signal
voltage across the full range of throttle movement to verify smooth operation.
Q9: A vehicle has a P0135 code set (O2 Sensor Heater Circuit Malfunction, Bank 1 Sensor 1).
What is the most likely cause?
A. Faulty oxygen sensor heater element
B. Faulty oxygen sensor signal wire
C. Faulty PCM
D. Vacuum leak
Answer: A
2026/2027/2028 Testing Cycle
100 Questions & Answers | Verified Rationales
Guaranteed Pass | Graded A+
,SECTION 1: ELECTRONIC CONTROLS (29 Questions)
Q1: A technician is checking the oxygen sensor during closed loop operation. The voltage is
fluctuating between 0.45 and 0.50 volts and does not vary. What does this indicate?
A. The sensor is functioning correctly
B. The sensor is sluggish and probably faulty
C. The sensor is stuck lean
D. The sensor is stuck rich
Answer: B
Rationale: A properly functioning O2 sensor should rapidly fluctuate between 0.1 and 0.9 volts.
A reading that stays near 0.45–0.50 volts (midpoint) with little variation indicates a sluggish or
contaminated sensor that is not responding to changes in exhaust oxygen content.
Q2: Technician A says the PCM uses the manifold absolute pressure (MAP) sensor to measure
engine load. Technician B says the PCM uses the MAP sensor to calculate fuel delivery. 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 MAP sensor measures intake manifold pressure/vacuum, which the PCM uses to
determine engine load and calculate the proper fuel delivery and ignition timing.
Q3: A vehicle has a P0101 code set. Technician A says this indicates a mass airflow sensor
performance problem. Technician B says this indicates a manifold absolute pressure sensor
problem. 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: P0101 is defined as "Mass Air Flow Circuit Range/Performance." The code
specifically relates to the MAF sensor and its circuit, not the MAP sensor.
Q4: A technician is testing a throttle position sensor. The voltage reading jumps erratically when
the throttle is slowly opened. What does this indicate?
A. The TPS is functioning correctly
B. The TPS has a dead spot or erratic signal
C. The PCM is faulty
D. The throttle cable is binding
Answer: B
Rationale: An erratic or jumpy TPS signal indicates a worn resistive element or dirty contacts
inside the sensor. The TPS should be replaced.
Q5: Technician A says a Hall-effect sensor produces a digital square wave signal. Technician B
says a variable reluctance sensor produces an analog AC voltage signal. 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: Hall-effect sensors produce a digital square wave (on/off) signal, while variable
reluctance sensors produce an analog AC voltage waveform whose amplitude and frequency
increase with speed.
Q6: A vehicle has a P0335 code set. Technician A says this indicates a crankshaft position sensor
circuit malfunction. Technician B says the engine may have a no-start condition. 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: P0335 is the crankshaft position sensor circuit code. When this sensor fails, the PCM
has no engine position reference, resulting in no spark and no fuel injector pulse — a no-start
condition.
Q7: Technician A says the PCM uses the engine coolant temperature (ECT) sensor to determine
fuel enrichment during cold start. Technician B says the PCM uses the intake air temperature
(IAT) sensor to determine fuel enrichment during cold start. 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: Both sensors provide critical input during cold start. The ECT tells the PCM the
engine is cold and needs enrichment, while the IAT helps the PCM calculate air density for
proper fuel delivery.
Q8: A technician is checking the reference voltage at the throttle position sensor. The
specification is 5.0 volts. The meter reads 5.0 volts. What should the technician do next?
A. Replace the TPS
B. Check the signal voltage at closed throttle and wide open throttle
C. Replace the PCM
D. Adjust the throttle cable
Answer: B
Rationale: With correct reference voltage confirmed, the next step is to check the TPS signal
voltage across the full range of throttle movement to verify smooth operation.
Q9: A vehicle has a P0135 code set (O2 Sensor Heater Circuit Malfunction, Bank 1 Sensor 1).
What is the most likely cause?
A. Faulty oxygen sensor heater element
B. Faulty oxygen sensor signal wire
C. Faulty PCM
D. Vacuum leak
Answer: A
