AutoCodes – GMC – B3445 GMC

B3445 GMC Code - Stop Lamp Circuit

Quick Answer

Battery voltage for the Center High Mounted Stop Lamp (CHMSL) is applied from the CHMSL/Back-up Fuse in the rear electrical center to the Body Control Module (BCM). Common causes include Faulty Center High Mounted Stop Lamp, Center High Mounted Stop Lamp harness is open or shorted, Center High Mounted Stop Lamp circuit poor electrical connection. 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: B3445 GMC indicates Stop Lamp Circuit.
Common causes: Common causes include Faulty Center High Mounted Stop Lamp, Center High Mounted Stop Lamp harness is open or shorted, Center High Mounted Stop Lamp circuit poor electrical connection.
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 1,563

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 Mar 08, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B3445 GMC Description

Battery voltage for the Center High Mounted Stop Lamp (CHMSL) is applied from the CHMSL/Back-up Fuse in the rear electrical center to the Body Control Module (BCM). When the brake pedal is applied, a signal is applied to the BCM. The BCM then applies a voltage to the CHMSL voltage supply circuit to the CHMSL. The Diagnostic Trouble Code (DTC) sets when the BCM detects a short to ground on the CHMSL voltage supply circuit when the stop lamps are being commanded ON.

OBDII Code B3445 GMC - Stop Lamp Circuit - AutoCodes.com — B3445 GMC Code - Stop Lamp Circuit

What does this mean?

What are the Possible Causes of the DTC B3445 GMC?

Faulty Center High Mounted Stop Lamp
Center High Mounted Stop Lamp harness is open or shorted
Center High Mounted Stop Lamp circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B3445 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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B3445 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.

Need more information about the B3445 GMC code?

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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 B3445 GMC Code

1. What does OBDII code B3445 GMC indicate?

The B3445 code for GMC vehicles refers to a Stop Lamp Circuit issue.

2. What are the common symptoms associated with OBDII code B3445 GMC?

Common symptoms of B3445 code include malfunctioning brake lights, illuminated brake warning light on the dashboard, and potentially impaired brake performance.

3. What are the possible causes of OBDII code B3445 GMC?

Possible causes of the B3445 code include a faulty brake light switch, damaged wiring or connectors in the stop lamp circuit, or a defective brake light control module.

4. How can I diagnose the OBDII code B3445 GMC?

Diagnosing the B3445 code involves inspecting the brake light switch, checking the wiring and connectors in the stop lamp circuit for damage, and testing the brake light control module for proper functioning.

5. Can I continue driving with the OBDII code B3445 GMC?

It is not recommended to continue driving with the B3445 code as it can affect the proper functioning of your brake lights, potentially compromising safety on the road.

6. How do I repair OBDII code B3445 GMC?

To repair the B3445 code, you may need to replace the faulty brake light switch, repair any damaged wiring or connectors in the stop lamp circuit, or replace the brake light control module if necessary.

7. Is it possible to reset the OBDII code B3445 GMC without repairs?

Resetting the B3445 code without addressing the underlying issue may temporarily turn off the warning light, but the problem will likely reoccur. It is best to diagnose and repair the issue to prevent further complications.

8. Can a DIY enthusiast fix the OBDII code B3445 GMC at home?

Depending on your automotive repair skills and access to tools, some DIY enthusiasts may be able to address the B3445 code by replacing the brake light switch or repairing damaged wiring. For complex issues, professional assistance may be needed.

9. Are there any safety implications of ignoring the OBDII code B3445 GMC?

Ignoring the B3445 code can pose safety risks as it may lead to non-functioning brake lights, which are essential for signaling your braking intentions to other drivers on the road. It is important to address the issue promptly.

10. How much can I expect to spend on repairing OBDII code B3445 GMC?

The cost of repairing the B3445 code can vary depending on the specific cause of the issue, labor rates in your area, and whether you choose to address the problem yourself or seek professional help. It is advisable to obtain a diagnosis from a mechanic for an accurate estimate.