AutoCodes – GMC – B2545 GMC

B2545 GMC Code - Backup Lamps Circuit

Quick Answer

The backup lamp relay is always supplied with battery voltage. Common causes include Blown Backup Lamp Fuse, Faulty Body Control Module (BCM), Body Control Module harness is open or shorted. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: B2545 GMC indicates Backup Lamps Circuit.
Common causes: Common causes include Blown Backup Lamp Fuse, Faulty Body Control Module (BCM), Body Control Module harness is open or shorted.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 2,974

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on May 24, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code B2545 GMC Description

The backup lamp relay is always supplied with battery voltage. With the engine running and the transmission in the reverse position, the Transmission Control Module (TCM) sends a serial data message to the Body Control Module (BCM). The message indicates that the gear selector is in the reverse position. The BCM energizes the backup lamp relay by applying battery voltage to the backup lamp relay control circuit. When the backup lamp relay is energized, the relay switch contacts close, and battery voltage is applied through the backup lamp fuses to the backup lamp control circuits which illuminate the backup lamps. Once the driver moves the gear selector out of the reverse position, a message is sent by the TCM via serial data requesting the BCM to remove the battery voltage from the backup lamp relay control circuit. The engine must be running for the backup lamps to operate. The Diagnostic Trouble Code (DTC) will be set when the BCM detects a problem with the backup lamps relay control circuit.

OBDII Code B2545 GMC - Backup Lamps Circuit - AutoCodes.com — B2545 GMC Code - Backup Lamps Circuit

What does this mean?

What are the Possible Causes of the DTC B2545 GMC?

Blown Backup Lamp Fuse
Faulty Body Control Module (BCM)
Body Control Module harness is open or shorted
Body Control Module circuit poor electrical connection

How to Fix the DTC B2545 GMC?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

B2545:01 Backup Lamps Circuit Short to Battery
B2545:02 Backup Lamps Circuit Short to Ground
B2545:02 Backup Lamps Circuit Open

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B2545 GMC code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Information for Specific GMC Models

B2545 2014 GMC Sierra — Backup Lamps Circuit
B2545 2015 GMC Sierra — Backup Lamps Circuit
B2545 2016 GMC Sierra — Backup Lamps Circuit
B2545 2017 GMC Sierra — Backup Lamps Circuit
B2545 2018 GMC Sierra — Backup Lamps Circuit

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about B2545 GMC Code

1. What are the common symptoms of OBDII code B2545 GMC related to the Backup Lamps Circuit?

- The common symptoms include inoperative backup lamps, flickering backup lamps, or backup lamps staying on continuously.

2. What are the possible causes of OBDII code B2545 GMC for the Backup Lamps Circuit?

- Possible causes may include a faulty backup lamp switch, damaged wiring or connectors in the circuit, a blown fuse, or a malfunctioning body control module.

3. How can I diagnose the issue causing OBDII code B2545 GMC for the Backup Lamps Circuit?

- You can start by checking the backup lamp fuse, inspecting the wiring and connectors for any damage, testing the backup lamp switch, and scanning the body control module for fault codes.

4. Can I repair OBDII code B2545 GMC related to the Backup Lamps Circuit myself?

- Depending on your level of automotive repair experience, you may be able to repair this issue yourself by replacing the faulty backup lamp switch, repairing damaged wiring, or addressing any other identified issues.

5. Is it safe to drive with OBDII code B2545 GMC triggered for the Backup Lamps Circuit?

- While driving with backup lamps not functioning may pose safety risks, it is generally safe to drive with this code as long as you remain cautious and aware of your surroundings when reversing.

6. How important are backup lamps, and why should I address OBDII code B2545 GMC for the Backup Lamps Circuit promptly?

- Backup lamps are crucial for visibility when reversing, especially in low-light conditions. It is recommended to address this code promptly to ensure your safety and the safety of others on the road.

7. Can weather conditions affect the operation of backup lamps and trigger OBDII code B2545 GMC for the Backup Lamps Circuit?

- Extreme weather conditions, such as moisture or extreme temperatures, can potentially impact the operation of backup lamps and contribute to triggering this OBDII code. Inspecting and protecting the wiring can help prevent weather-related issues.

8. Are there any specific tools I need to diagnose OBDII code B2545 GMC for the Backup Lamps Circuit?

- Basic automotive tools such as a multimeter, wiring diagram for your vehicle, and a scan tool capable of reading body control module codes may be helpful in diagnosing this issue.

9. How can I prevent OBDII code B2545 GMC related to the Backup Lamps Circuit from recurring?

- To prevent this code from recurring, regularly inspect the backup lamp circuit for any signs of damage, ensure proper connections, and promptly address any issues with the backup lamp system.

10. Is resetting the OBDII system sufficient to clear code B2545 GMC for the Backup Lamps Circuit?

- While resetting the OBDII system may temporarily clear the code, it is essential to diagnose and address the underlying issue triggering the code to prevent it from reoccurring.