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 B2545 00: Backup Lamps Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Back Up Lamps Control | B2545 00 | 1 | 2 | --
1. Backup Lamps Inoperative 2. Backup Lamps Always On

### Circuit/System Description

When the PRNDL is placed in the REVERSE position, a signal is sent to the body control module (BCM). The BCM then applies voltage through the backup lamps control circuit to the back up lamps. The back up lamps are grounded through G401.

### Conditions for Running the DTC

• | The ignition is ON.

• | The back up lamps must be commanded ON.

### Conditions for Setting the DTC

The BCM detects a short to ground on the back up lamp control circuit when the back up lamps are being commanded ON.

### Action Taken When the DTC Sets

The back up lamps do not illuminate.

### Conditions for Clearing the DTC

• | The conditions for setting the DTC are no longer present.

• | A history DTC clears after 100 malfunction-free ignition cycles.

### Reference Information

#### Schematic Reference

Exterior Lights Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Exterior Lighting Systems Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

Ignition ON, command the Backup Lamps ON with a scan tool. The Backup Lamps parameter should display On and the backup lamps should illuminate.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the left back up lamp.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal listed below and B+:

• | RPO WDA -- terminal 1

• | RPO Z88 -- terminal 2

• | RPO W49 -- terminal A

⇒ | If the test lamp illuminates, test the control circuit for a short to ground.

3. If all circuits test normal, replace the BCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming