On GM OBD II vehicles, the PCM tests EGR operation by turning EGR on and off and monitoring which of the following sensors?
A) MAP sensor
B) TPS
C) ECT sensor
D) VSS

Question

Quizplus · Accepted Answer

The PCM tests EGR operation by monitoring the MAP (Manifold Absolute Pressure) sensor. When the EGR valve is opened, the intake manifold vacuum changes, which is detected by the MAP sensor. This change in vacuum helps the PCM determine if the EGR system is operating correctly.

On GM OBD II Vehicles, the PCM Tests EGR Operation