Circuit Description
There should always be a steady malfunction indicator lamp (MIL) when the ignition switch is in the ON position and the engine is not running. System voltage is applied to the indicator bulb and the instrument panel cluster (IPC) provides a path to ground. Once the engine starts, the IPC turns OFF the MIL. When an engine control system malfunction occurs, the PCM sends a message over the controller area network (CAN) to the body control module (BCM) requesting the MIL. The BCM then sends a message to the IPC over class 2 requesting MIL illumination.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | |||
1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | |
Observe the instrument panel cluster (IPC) assembly operation. Do all other functions of the IPC function normally? | Go to Step 3 | Go to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gages and Console | |
3 | Replace the IPC. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console. Did you complete the replacement? | Go to Step 4 | -- |
4 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
