The most likely cause is a internally failed PCM.
I listed possible causes below.
Engine Control Module (ECM)
Instrument Panel Cluster (IPC) Malfunction
Malfunction Indicator Lamp (MIL) Control Circuit Open or High Resistance
Malfunction Indicator Lamp (MIL) Control Circuit Short to Voltage
Malfunction Indicator Lamp (MIL) Ignition Voltage Circuit Open or Short to Ground
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.
CONDITIONS FOR RUNNING THE DTC
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 1 second.
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.
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 1 volt from the MIL control circuit in the ECM harness connector to a good ground.
- If there is more than 1 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 3-amp 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.
IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure. See: All Diagnostic Trouble Codes ( DTC ) > Verification Tests
Control Module References for ECM replacement, setup, and programming
Monday, November 12th, 2018 AT 8:39 AM