Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

The malfunction indicator lamp (MIL) is located on the instrument panel cluster (IPC).

The MIL informs the driver that an emission system fault has occurred and that the engine control system requires service. The control module monitors the MIL control circuit for conditions that are incorrect for the commanded states of the MIL.

DTC P0650 runs continuously when the ignition is ON.

The control module detects that the commanded state of the MIL driver and the actual state of the control circuit do not match for more than one second.

DTC P0650 is a Type B DTCs.

DTC P0650 is a Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

Scan Tool Reference

DTC Type Reference

Turn ON the ignition, then command the MIL ON and OFF with a scan tool. The MIL should turn ON and OFF when commanded.

1. Turn OFF the ignition.
2. Disconnect the engine control module (ECM).
3. Turn ON the ignition with the engine OFF.

⇒	If the MIL is still ON, test the MIL control circuit for a short to ground.

⇒	If the MIL control circuit tested OK and the MIL stayed ON, replace the IPC.

⇒	If the MIL control circuit tested OK and the MIL went out when the ECM was disconnected, replace the ECM.

4. Measure for 12 volts from the MIL ignition voltage circuit in the IPC harness connector to a ground.

⇒	If there is less than 12 volts, test the MIL ignition voltage circuit for an open, or a short to ground and an open fuse.

5. Remove the fuse that supplies voltage to the MIL.
6. Measure for less than one volt from the MIL control circuit in the ECM harness connector to a good ground.

⇒	If there is more than one volt, test the MIL control circuit for a short to voltage.

7. Install the fuse that supplies voltage to the MIL.
8. The MIL should illuminate with a 3A fused jumper wire connected between the MIL control circuit in the ECM harness connector and a good ground.

⇒	If the MIL does not illuminate, test the MIL control circuit for an open or high resistance.

⇒	If the MIL control circuit tests OK, replace the IPC.

⇒	If the MIL does illuminate, but does not when commanded ON with a scan tool, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.