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.

### Circuit/System Description

The body control module (BCM) calculates the mileage based on the vehicle speed signal circuit from the engine control module (ECM). The BCM then sends a serial data message to the instrument panel cluster (IPC) indicating the value of the odometer. The odometer will display 'error' if an internal BCM memory failure is detected. The odometer displays either miles or kilometers and the desired units can be accessed by pressing the trip/reset switch.

### Reference Information

#### Schematic Reference

Instrument Cluster Schematics

#### Connector End View Reference

Displays and Gages Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Scan Tool Data List

### Circuit/System Testing

1. Ignition OFF, disconnect the DIC switch connector.
2. Test for less than 1 ohm of resistance between the DIC switch ground circuit and ground.

⇒ | If greater than 1 ohm, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Trip Reset Switch parameter is Inactive.

⇒ | If not inactive, test the signal circuit for a short to ground. If the circuit tests normal, replace the IPC.

4. Install a 3-amp fused jumper wire between the signal circuit and ground. Verify the scan tool Trip Reset Switch parameter is Active.

⇒ | If not active, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the IPC.

5. If all circuits test normal, test or replace the DIC switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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

• | Steering Wheel Control Switch Assembly Replacement