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 powertrain control module (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 number below refers to the step number 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 - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
Observe the instrument panel cluster (IPC) assembly operation. Do all other functions of the IPC function normally? | Go to Step 3 | Go to Symptoms - Instrument Panel, Gages and Console 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 |
