B2545

DTC B2545

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptor
DTC B2545 01
- Backup Lamps Circuit Short to Battery

DTC B2545 06
- Backup Lamps Circuit Short to Ground or Open




Circuit/System Description

The backup lamp relay is controlled by the body control module (BCM). The BCM provides ground to the backup lamp relay control circuit in order to turn ON the backup lamp relay. When the backup lamp relay control circuit opens, becomes shorted to voltage, or becomes shorted to ground without being commanded ON by the BCM, DTC B2545 is set.


Conditions for Running the DTC

The ignition switch is in the ON position.


Conditions for Setting the DTC

B2545 01

Will set if there is a short to voltage in the backup lamp relay control circuit.

B2545 06

Will set if there is an open or short to ground in the backup lamp relay control circuit.


Action Taken When the DTC Sets

* If the backup lamp relay control circuit is shorted to ground, the backup lamps are always ON when the ignition is ON.
* If the backup lamp relay control circuit is open, the backup lamps are inoperative.



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 (Exterior Lights Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Exterior Lighting Systems Description and Operation (Exterior Lighting Systems Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information


Circuit/System Testing

1. Ignition OFF, disconnect the BU/LP relay.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit of the BU/LP relay and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Connect a test lamp between the B+ circuit of the BU/LP relay and the control circuit of the BU/LP relay.
4. Command the backup lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.


• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, replace the BU/LP relay.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming