AutoCodes – GMC – B3884 GMC

B3884 GMC Code - Center High Mounted Stop Lamp Circuit

Quick Answer

The brake pedal position sensor is used to sense the action of the driver's application of the brake pedal. 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: B3884 GMC indicates Center High Mounted 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 1,212

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 Jun 16, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code B3884 GMC Description

The brake pedal position sensor is used to sense the action of the driver's application of the brake pedal. The brake pedal position sensor provides an analog voltage signal that will increase as the brake pedal is applied. The Body Control Module (BCM) provides a low reference signal and a 5 V reference voltage to the brake pedal position sensor. When the variable signal reaches a voltage threshold indicating the brakes have been applied, the BCM energizes the stop lamp relay by applying a voltage to the stop lamp relay control circuit. When the stop lamp relay is energized, the relay switch contacts close, and battery voltage is applied to the Center High Mounted Stop Lamp (CHMSL) control circuit which illuminates the CHMSL. The Diagnostic Trouble Code (DTC) will be set when the BCM detects a malfunction in the stop lamp relay control circuit.

OBDII Code B3884 GMC - Center High Mounted Stop Lamp Circuit - AutoCodes.com — B3884 GMC Code - Center High Mounted Stop Lamp Circuit

What does this mean?

What are the Possible Causes of the DTC B3884 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 B3884 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

B3884:01 Center High Mounted Stop Lamp Circuit Short to Battery
B3884:02 Center High Mounted Stop Lamp Circuit Short to Ground
B3884:04 Center High Mounted Stop Lamp Circuit Open

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B3884 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 B3884 GMC code?

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Information for Specific GMC Models

B3884 2014 GMC Sierra — Center High Mounted Stop Lamp Circuit
B3884 2015 GMC Sierra — Center High Mounted Stop Lamp Circuit
B3884 2016 GMC Sierra — Center High Mounted Stop Lamp Circuit
B3884 2017 GMC Sierra — Center High Mounted Stop Lamp Circuit
B3884 2018 GMC Sierra — Center High Mounted Stop Lamp 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 B3884 GMC Code

1. What are the common symptoms of OBDII code B3884 GMC?

- The common symptoms of OBDII code B3884 GMC include the center high mounted stop lamp (CHMSL) not illuminating when the brake pedal is pressed.

2. What can cause OBDII code B3884 GMC to be triggered?

- OBDII code B3884 GMC is typically triggered due to a malfunction in the CHMSL circuit, such as a faulty CHMSL bulb, wiring issue, or a defective CHMSL module.

3. How can I diagnose the cause of OBDII code B3884 GMC?

- To diagnose OBDII code B3884 GMC, you can start by checking the CHMSL bulb for any signs of damage or corrosion. Next, inspect the wiring harness for any breaks or shorts. Finally, test the CHMSL module for proper functionality.

4. Can I repair OBDII code B3884 GMC myself?

- If you have experience with automotive electrical systems, you may be able to repair OBDII code B3884 GMC yourself by replacing the faulty CHMSL bulb, repairing any damaged wiring, or replacing the defective CHMSL module.

5. Are there any quick tips to troubleshoot OBDII code B3884 GMC?

- A quick tip to troubleshoot OBDII code B3884 GMC is to visually inspect the CHMSL bulb and wiring first, as these are common areas where issues arise. Additionally, using a multimeter to test for continuity in the circuit can help pinpoint the problem.

6. What are the potential risks of ignoring OBDII code B3884 GMC?

- Ignoring OBDII code B3884 GMC can pose a safety hazard as the CHMSL is an important component for signaling braking to other drivers. It is recommended to address this issue promptly to ensure proper brake light functionality.

7. Can extreme weather conditions affect OBDII code B3884 GMC?

- Extreme weather conditions such as excessive heat or moisture can potentially damage the CHMSL bulb or wiring, leading to the triggering of OBDII code B3884 GMC. It's important to protect the CHMSL components from harsh elements.

8. Is it necessary to reset the OBDII system after repairing OBDII code B3884 GMC?

- After repairing OBDII code B3884 GMC, it is recommended to reset the OBDII system using an OBDII scanner to clear the trouble code. This will ensure that the system recognizes the repairs and monitors the CHMSL circuit properly.

9. Can a loose CHMSL connection cause OBDII code B3884 GMC?

- Yes, a loose or poor connection in the CHMSL circuit can lead to OBDII code B3884 GMC being triggered. Make sure all connections are secure and free of corrosion when troubleshooting this issue.

10. How can I prevent OBDII code B3884 GMC from recurring in the future?

- To prevent OBDII code B3884 GMC from recurring, regularly inspect and maintain the CHMSL components, including the bulb, wiring, and module. Keeping these components in good condition can help avoid future issues with the CHMSL circuit.