Test Description

WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

2 - This step checks whether there is communication between PCM and a scan tool device. If PCM is unable to provide serial data to the scan tool, there will be no MIL control.
3 - If other Instrument Panel Cluster (IPC) functions are not working correctly check for an open GAUGE fuse or for a lack of power and ground to IPC.
4 - This step checks for an open MIL control circuit or for an internal PCM failure.
5 - An open fuse determines if a voltage is constantly being applied to the control circuit.

MIL Illumination

MIL will illuminate with ignition switch in RUN position and engine not running.
MIL will turn OFF when engine is started.
MIL will remain illuminated if self-diagnostic system has detected a malfunction.
MIL may turn OFF if malfunction is not present.
If MIL is illuminated and then the engine stalls, MIL will remain illuminated so long as the ignition switch is in RUN position.
If MIL is not illuminated and engine stalls, MIL will not illuminate until the ignition switch is cycled OFF, then to RUN position.

Perform the Diagnostic System Check - Engine Controls, when the following conditions are present:

MIL does not illuminate when ignition switch is turned to RUN position. See MIL OPERATION .
MIL remains illuminated while engine is running.
MIL is flashing while engine is running.
A driveability symptom is determined.