Ignition voltage is supplied to the malfunction indicator lamp (MIL). The engine control module (ECM) turns the MIL ON by grounding the MIL control circuit.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, the MIL should turn ON and OFF when commanded with a scan tool.

1. Ignition ON, verify that the P16 Instrument Panel Cluster (IPC) warning indicators are illuminated.

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If the P16 Instrument Panel Cluster (IPC) warning indicators are not illuminated, test the P16 Instrument Panel Cluster (IPC) ignition circuit terminal 31 for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, replace the P16 Instrument Panel Cluster (IPC).

2. Ignition OFF, disconnect connector X1 at the K20 Engine Control Module (ECM).
3. Ignition ON, verify that the MIL is not illuminated.

⇒	If the MIL is illuminated, inspect the MIL control circuit K20 Engine Control Module (ECM) terminal X1-1 circuit for a short to ground. If the circuit tests normal, replace the P16 Instrument Panel Cluster (IPC).

4. Ignition ON, verify that the MIL illuminates with a 3 A fused jumper between the MIL control circuit (ECM) terminal 1 (X1) and ground

⇒	If the MIL does not illuminate, test the MIL control (ECM) terminal 1 (X1) circuit for a short to voltage or an open / high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.