• | 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 | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Backup Lamps Voltage Supply | B2545 00 | 1 | 2 | -- |
|
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 relay control circuit to the BCK/UP lamp relay in the underhood fuse block, inside rearview mirror, and rearview camera module. The BCK/UP lamp relay then illuminates the backup lamps.
• | The ignition is ON. |
• | The backup lamps must be commanded ON. |
The BCM detects a short to ground on the backup lamp relay control circuit when the backup lamps are being commanded ON.
The backup lamps do not illuminate.
• | The conditions for setting the DTC are no longer present. |
• | A history DTC clears after 100 malfunction-free ignition cycles. |
• | The BCM receives the clear code command from the scan tool. |
Lighting Systems Connector End Views
Ignition ON, activate the Backup Lamps output control on the scan tool. The Backup Lamps parameter in the data list should display On and the backup lamps should illuminate.
⇒ | If the circuit exhibits a ground signal, repair the short to ground in the control circuit. |
⇒ | If the circuit now exhibits a ground signal of 20 ohms or less, replace the inside rearview mirror. |
⇒ | If the circuit now exhibits a ground signal of 20 ohms or less, replace the underhood fuse block. |
⇒ | If the circuit now exhibits a ground signal of 20 ohms or less, replace the rearview camera module. |
⇒ | If the circuit does not exhibit a ground, replace the BCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
For BCM replacement, setup, and programming refer to Control Module References .