P0650

DTC P0650

DTC DESCRIPTOR

DTC P0650
Malfunction Indicator Lamp (MIL) Control Circuit

DIAGNOSTIC FAULT INFORMATION






IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

CIRCUIT/SYSTEM DESCRIPTION
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 engine control module (ECM) performs a self test for the MIL lamp and its circuitry by commanding the MIL ON and OFF every time the engine is started. The ECM monitors the MIL control circuit for conditions that are incorrect for the commanded states of the MIL.

CONDITIONS FOR RUNNING THE DTC
- The MIL lamp must be commanded ON.
- DTC P0650 runs continuously when the ignition is ON.

CONDITIONS FOR SETTING THE DTC
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 3 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.

CIRCUIT/SYSTEM VERIFICATION
Turn ON the ignition, command the MIL ON and OFF with a scan tool.
- The MIL lamp should turn ON and OFF when commanded ON and OFF.

CIRCUIT/SYSTEM TESTING
1. Inspect the fuse that supplies voltage to the MIL.
- If the fuse is open test all spiced ignition 1 voltage circuits and components for a short to ground.
2. With the ignition ON, and the ECM harness disconnected, the MIL should be OFF.
- If the MIL is ON, test the MIL control circuit for a short to ground, or a faulty IPC.
3. With the ignition ON, the ECM harness disconnected, connect a fused 3-amp jumper wire to the MIL control circuit. Connecting and disconnecting the other end of the fused jumper wire to a ground will allow the MIL to turn ON and OFF.
- If the MIL turns ON and OFF when the jumper is connected and disconnected from a ground, replace the ECM.
- If the fuse in the 3-amp fused jumper opens, test the MIL control circuit for a short to voltage.
- If the MIL does not illuminate, test the MIL control and the MIL supply voltage circuits for an open.

REPAIR INSTRUCTIONS

IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM and IPC replacement, setup, and programming.