AutoCodes – Generic – B3951:04

B3951:04 Code - Right Rear Turn Signal Circuit Open

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: B3951:04 indicates Right Rear Turn Signal Circuit Open.
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 401

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 B3951:04 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 an open/high resistance in the right rear turn signal control circuit.

OBDII Code B3951:04 - Right Rear Turn Signal Circuit Open - AutoCodes.com — B3951:04 Code - Right Rear Turn Signal Circuit Open

What does this mean?

What are the Possible Causes of the DTC B3951:04?

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 B3951:04?

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 B3951:04 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 B3951:04 Code

1. What are the common symptoms of OBDII code B3951:04 (Right Rear Turn Signal Circuit Open)?

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

2. What are the possible causes of the OBDII code B3951:04?

- The code B3951:04 indicates a right rear turn signal circuit open, which could be caused by a damaged wiring harness, a faulty turn signal bulb, a corroded connector, or a problem with the turn signal switch.

3. How can I diagnose the issue related to the OBDII code B3951:04?

- You can start by visually inspecting the right rear turn signal bulb, checking the wiring harness for any damage, testing the turn signal switch, and using a multimeter to check for continuity in the circuit.

4. Is it safe to continue driving with the OBDII code B3951:04 active?

- It is 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.

5. How can I repair the right rear turn signal circuit open issue related to OBDII code B3951:04?

- To repair the issue, you may need to replace the right rear turn signal bulb, repair or replace any damaged wiring, clean or replace corroded connectors, or replace the turn signal switch if necessary.

6. Can a DIY enthusiast fix the OBDII code B3951:04 at home?

- Depending on your level of automotive expertise, you may be able to address the issue at home by following repair guides or tutorials. However, if you are unsure, it's best to consult a professional mechanic.

7. Will resetting the OBDII system clear the B3951:04 code?

- Resetting the OBDII system may temporarily clear the code, but if the underlying issue causing the right rear turn signal circuit open is not fixed, the code is likely to reappear.

8. How much can I expect to pay for professional repairs related to the OBDII code B3951:04?

- The cost of repairs can vary depending on the specific cause of the issue and labor rates in your area. It's advisable to get a diagnostic inspection done to get an accurate estimate.

9. Are there any preventive measures to avoid encountering the OBDII code B3951:04 in the future?

- Regularly checking and maintaining your vehicle's lighting system, including turn signal bulbs and wiring, can help prevent issues like a right rear turn signal circuit open.

10. Can the OBDII code B3951:04 affect other vehicle systems?

- While the code specifically relates to the right rear turn signal circuit, electrical issues in one part of the vehicle can sometimes impact other systems. It's essential to address the problem promptly to prevent any further complications.