Chapter 24: Engine Performance
systems Exam Actual Questions and
Answers 2026
Which sensor is used for misfire monitoring on OBD II systems? -
correct answer ✅Crankshaft position sensor
DTCs that will not affect emissions will never -
correct answer ✅illuminate the MIL.
An active or current DTC represents a fault that was detected and
occurred during -
correct answer ✅two trips.
There are some DTCs that will set in -
correct answer ✅one trip.
A computer is not capable of -
correct answer ✅control the vehicle's operating conditions
Which of the following memory circuits is used to store trouble
codes and other temporary information? -
correct answer ✅Random access memory
, Chapter 24: Engine Performance
systems Exam Actual Questions and
Answers 2026
Technician A says that the oxygen sensor provides the major input
during the open-loop mode. Technician B says that the coolant
temperature sensor input is not used during open-loop mode
operation. Who is correct? -
correct answer ✅Neither A nor B
While discussing OBD II systems: Technician A says that the PCM
illuminates the MIL if a defect causes emission levels to exceed 2.5
times the emission standards for that model year vehicle.
Technician B says that if a misfire condition threatens engine or
catalyst damage, the PCM flashes the MIL. Who is correct? -
correct answer ✅Technician B
While discussing the catalyst efficiency monitor: Technician A says
that if the catalytic converter is not reducing emissions properly,
the voltage frequency increases on the downstream HO2S.
Technician B says that if a fault occurs in the catalyst monitor
system on three drive cycles, the MIL will be illuminated. Who is
correct? -
correct answer ✅Both A and B
systems Exam Actual Questions and
Answers 2026
Which sensor is used for misfire monitoring on OBD II systems? -
correct answer ✅Crankshaft position sensor
DTCs that will not affect emissions will never -
correct answer ✅illuminate the MIL.
An active or current DTC represents a fault that was detected and
occurred during -
correct answer ✅two trips.
There are some DTCs that will set in -
correct answer ✅one trip.
A computer is not capable of -
correct answer ✅control the vehicle's operating conditions
Which of the following memory circuits is used to store trouble
codes and other temporary information? -
correct answer ✅Random access memory
, Chapter 24: Engine Performance
systems Exam Actual Questions and
Answers 2026
Technician A says that the oxygen sensor provides the major input
during the open-loop mode. Technician B says that the coolant
temperature sensor input is not used during open-loop mode
operation. Who is correct? -
correct answer ✅Neither A nor B
While discussing OBD II systems: Technician A says that the PCM
illuminates the MIL if a defect causes emission levels to exceed 2.5
times the emission standards for that model year vehicle.
Technician B says that if a misfire condition threatens engine or
catalyst damage, the PCM flashes the MIL. Who is correct? -
correct answer ✅Technician B
While discussing the catalyst efficiency monitor: Technician A says
that if the catalytic converter is not reducing emissions properly,
the voltage frequency increases on the downstream HO2S.
Technician B says that if a fault occurs in the catalyst monitor
system on three drive cycles, the MIL will be illuminated. Who is
correct? -
correct answer ✅Both A and B
