AutoCodes – GMC – B3951 2017 GMC Sierra

B3951 2017 GMC Sierra Code - Right Rear Turn Signal Circuit

Quick Answer

Ground is applied at all times to the turn signal/multifunction switch. Common causes include Faulty Right Rear Turn Signal Lamp, Right Rear Turn Signal Lamp harness is open or shorted, Right Rear Turn Signal 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: B3951 2017 GMC Sierra indicates Right Rear Turn Signal Circuit.
Common causes: Common causes include Faulty Right Rear Turn Signal Lamp, Right Rear Turn Signal Lamp harness is open or shorted, Right Rear Turn Signal 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 205

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Basic DIY (1 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 17, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code B3951 2017 GMC Sierra Description

Ground is applied at all times to the turn signal/multifunction switch. The turn signal lamps may only be activated with the ignition switch in the ON or START positions. When the turn signal/multifunction switch is placed in either the TURN RIGHT or TURN LEFT position, ground is applied to the Body Control Module (BCM) through either the right turn or left turn signal switch signal circuit. The BCM responds to the turn signal switch input by applying a pulsating voltage to the front and rear turn signal lamps through there respective control circuits. When a turn signal request is received by the BCM, a serial data message is sent to the instrument cluster requesting the respective turn signal indicator be pulsed ON and OFF. The Diagnostic Trouble Code (DTC) will be set when the BCM detects a short to voltage, short to ground, or an open/high resistance in the right rear turn signal control circuit.

OBDII Code B3951 2017 GMC Sierra - Right Rear Turn Signal Circuit - AutoCodes.com — B3951 2017 GMC Sierra Code - Right Rear Turn Signal Circuit

What does this mean?

What are the Possible Causes of the DTC B3951 2017 GMC Sierra?

Faulty Right Rear Turn Signal Lamp
Right Rear Turn Signal Lamp harness is open or shorted
Right Rear Turn Signal Lamp circuit poor electrical connection

How to Fix the DTC B3951 2017 GMC Sierra?

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

B3951:01 Right Rear Turn Signal Circuit Short to Battery
B3951:02 Right Rear Turn Signal Circuit Short to Ground
B3951:04 Right Rear Turn Signal Circuit Open

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B3951 2017 GMC Sierra 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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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 B3951 2017 GMC Sierra Code

1. What are the common symptoms of OBDII code B3951 in a 2017 GMC Sierra related to the right rear turn signal circuit?

- The common symptoms include the right rear turn signal not working, rapid flashing of the turn signal, or a warning light on the dashboard.

2. What are the possible causes of OBDII code B3951 in a 2017 GMC Sierra for the right rear turn signal circuit?

- Possible causes may include a faulty turn signal bulb, a damaged wiring harness, a defective turn signal switch, or a malfunctioning body control module.

3. How can I diagnose OBDII code B3951 in a 2017 GMC Sierra for the right rear turn signal circuit?

- You can start by visually inspecting the right rear turn signal bulb, checking the wiring for any damage, testing the turn signal switch, and using a diagnostic scanner to read the trouble codes.

4. Can I repair OBDII code B3951 in a 2017 GMC Sierra for the right rear turn signal circuit myself?

- Depending on your skill level and access to tools, you may be able to replace a faulty bulb or repair a damaged wire yourself. For more complex issues, it's recommended to consult a professional mechanic.

5. Is it safe to continue driving with OBDII code B3951 in a 2017 GMC Sierra affecting the right rear turn signal circuit?

- It's not recommended to drive with a malfunctioning turn signal as it can pose a safety hazard to you and other drivers on the road. It's best to address the issue promptly.

6. How much does it typically cost to repair OBDII code B3951 in a 2017 GMC Sierra related to the right rear turn signal circuit?

- The cost of repair can vary depending on the root cause of the issue. Simple fixes like replacing a bulb may be inexpensive, while more complex repairs involving wiring or components can be more costly.

7. Can weather conditions affect OBDII code B3951 in a 2017 GMC Sierra for the right rear turn signal circuit?

- Extreme weather conditions, such as heavy rain or snow, can potentially damage the wiring or connections related to the turn signal circuit, leading to the triggering of this OBDII code.

8. Will resetting the OBDII system clear OBDII code B3951 in a 2017 GMC Sierra for the right rear turn signal circuit?

- Resetting the OBDII system may temporarily clear the code, but if the underlying issue causing the code is not addressed, it is likely to reappear. It's important to diagnose and fix the root cause.

9. Can a dead battery trigger OBDII code B3951 in a 2017 GMC Sierra affecting the right rear turn signal circuit?

- A dead or low battery can sometimes cause electrical issues that may trigger fault codes like B3951. Ensure your battery is in good condition and properly charged.

10. How long does it typically take to repair OBDII code B3951 in a 2017 GMC Sierra for the right rear turn signal circuit?

- The repair time can vary depending on the exact cause of the issue and the complexity of the repair. Simple fixes may take less than an hour, while more involved repairs could take several hours or more.