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?
A)A only
B)B only
C)both A and B
D)neither A nor B

Question

Quizplus · Accepted Answer

Both Technician A and Technician B are correct. The PCM (Powertrain Control Module) adjusts the ignition timing to stabilize engine idle speed and retards timing in response to knock detection to prevent engine damage.

Ignition Timing Is Being Discussed