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
DTC P0650 01: Malfunction Indicator Lamp (MIL) Control Circuit Short to Battery
DTC P0650 02: Malfunction Indicator Lamp (MIL) Control Circuit Short to Ground
DTC P0650 04: Malfunction Indicator Lamp (MIL) Control Circuit Open Circuit
DTC P0650 54: Malfunction Indicator Lamp (MIL) Control Circuit Temperature High

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
MIL Voltage Supply | P0650, P0650 02 | P0650, P0650 04 | -- | --
MIL Control | P0650, P0650 02 | P0650, P0650 04 | P0650, P0650 01 | --

### 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) monitors the MIL control circuit for conditions that are incorrect for the commanded state of the MIL. For example, a failure condition exists if the ECM detects low voltage when the MIL is commanded OFF, or high voltage when the MIL is commanded ON.

### Conditions for Running the DTC

• | The ignition is ON.

• | The ignition voltage is between 8.5-16.5 volts.

• | DTC P0650 runs continuously once the above conditions are met .

### Conditions for Setting the DTC

#### P0650 01

The ECM detects a short to voltage on the circuit that controls the MIL.

#### P0650 02

The ECM detects a short to ground on the circuit that controls the MIL.

#### P0650 04

The ECM detects an open on the circuit that controls the MIL.

#### P0650 54

The ECM detects that the internal output driver is over temperature.

### 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

#### Connector End View Reference

• | Engine Control Module Connector End Views

• | Engine Controls Connector End Views

#### 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

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Output Controls

### Circuit/System Verification

Ignition ON, command the MIL ON and OFF with a scan tool. The MIL should turn ON and OFF as commanded.

### Circuit/System Testing

1. If any other IPC indicators or gages are inoperative, refer to Symptoms - Instrument Panel, Gages and Console .
2. Ignition OFF, disconnect the ECM harness connectors. Ignition ON, the MIL should not illuminate.

⇒ | If the MIL is illuminated, test the MIL control circuit for a short to ground. If the circuit tests normal, replace the IPC.

3. 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 IPC/bulb.

4. If all circuits/connections test normal, replace the ECM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Instrument Cluster Replacement or Instrument Cluster Bulb Replacement

• | Control Module References for engine control module replacement, setup, and programming