For 1990-2009 cars

### Diagnostic Instructions

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

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC P0650: Malfunction Indicator Lamp (MIL) Control Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
MIL Voltage Supply | P0650 | P0650 | -- | --
MIL Control | P0650/MIL ON | P0650 | P0650 | --

### Circuit/System Description

The malfunction indicator lamp (MIL) is located on the driver information center (DIC)/clock. Ignition 1 voltage is supplied directly to the MIL. The engine control module (ECM) turns the MIL ON by grounding the MIL control circuit. There should be a steady MIL with the ignition ON and the engine OFF.

### Conditions for Running the DTC

• | The engine is operating.

• | The ignition 1 voltage is between 7.5-16 volts.

• | The DTCs runs continuously once the above conditions are met.

### Conditions for Setting the DTC

The ECM detects the MIL control circuit is open or shorted to ground or voltage.

### Action Taken When the DTC Sets

DTC P0650 is a Type C DTC.

### Conditions for Clearing the DTC

DTC P0650 is a Type C DTC.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Engine idling, command the MIL ON and OFF with a scan tool. The MIL should turn ON and OFF.
2. Observe the DTC information with a scan tool. DTC P0650 should not set.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

### Circuit/System Testing

1. If any other indicators are inoperative on the DIC/clock, refer to Clock Malfunction.
2. Ignition OFF, disconnect the ECM harness connector.

• | MR 140 controller terminal K64

• | MT 34 controller terminal C49

3. Ignition ON, the MIL should not illuminate.

⇒ | If the MIL illuminates, test the MIL control circuit for a short to ground. If the circuit test normal, replace the DIC/clock.

4. Ignition ON, connect a 3A fused jumper wire between the MIL control circuit and ground. The MIL should illuminate.

⇒ | If the MIL does not illuminate, test the MIL control circuit for a short to voltage or an open/high resistance. If the circuit test normal, replace the DIC/clock.

⇒ | If the MIL illuminates, inspect for a poor connection or replace the ECM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Clock Replacement

• | Control Module References for ECM replacement, setup, and programming