Ignition timing calculations by the PCM are made by monitoring all of the following sensors EXCEPT:
A) The tach reference pulse (CKP/CMP sensors)
B) The manifold absolute pressure (MAP) sensor
C) The coolant temperature (ECT) sensor
D) The intake air temperature (IAT) sensor

Question

Quizplus · Accepted Answer

The intake air temperature (IAT) sensor is not directly involved in ignition timing calculations by the Powertrain Control Module (PCM). The PCM primarily uses the crankshaft position (CKP) and camshaft position (CMP) sensors for determining engine speed and position, the manifold absolute pressure (MAP) sensor for engine load, and the coolant temperature (ECT) sensor for engine temperature, all of which are critical for calculating the correct ignition timing. The IAT sensor mainly influences fuel delivery adjustments rather than ignition timing.

Ignition Timing Calculations by the PCM Are Made by Monitoring