AutoCodes – Generic – B3949

B3949 Code - Right Front Turn Signal Circuit

Quick Answer

Ground is applied at all times to the turn signal/multifunction switch. Common causes include Faulty Right Front Turn Signal Lamp, Right Front Turn Signal Lamp harness is open or shorted, Right Front 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: B3949 indicates Right Front Turn Signal Circuit.
Common causes: Common causes include Faulty Right Front Turn Signal Lamp, Right Front Turn Signal Lamp harness is open or shorted, Right Front 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 2,041

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 17, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B3949 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 left front turn signal control circuit.

OBDII Code B3949 - Right Front Turn Signal Circuit - AutoCodes.com — B3949 Code - Right Front Turn Signal Circuit

What does this mean?

What are the Possible Causes of the DTC B3949?

Faulty Right Front Turn Signal Lamp
Right Front Turn Signal Lamp harness is open or shorted
Right Front Turn Signal Lamp circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B3949?

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 B3949 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 B3949 code?

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Need Help with the Code?

Get the B3949 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B3949 Buick — Right Front Turn Signal Circuit
B3949 Cadillac — Right Front Turn Signal Circuit
B3949 Chevrolet — Right Front Turn Signal Circuit
B3949 GMC — Right Front Turn Signal Circuit
B3949 Pontiac — Right Front Turn Signal Circuit
B3949 Saturn — Right Front Turn Signal 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 B3949 Code

1. What are the common symptoms of OBDII code B3949 (Right Front Turn Signal Circuit)?

The common symptoms of code B3949 include the right front turn signal not working, fast blinking of the turn signal indicator, or a warning light on the dashboard.

2. What are the possible causes of OBDII code B3949?

The possible causes of code B3949 can be a faulty turn signal bulb, damaged wiring harness, a malfunctioning turn signal switch, or a faulty body control module.

3. How can I diagnose the issue related to OBDII code B3949?

To diagnose the issue related to code B3949, you can start by visually inspecting the right front turn signal bulb, checking the wiring for any damage, and using a multimeter to test for continuity in the circuit.

4. Can a DIY enthusiast repair OBDII code B3949 at home?

Yes, depending on the cause of the issue, DIY enthusiasts can repair code B3949 at home by replacing the faulty turn signal bulb, repairing damaged wiring, or replacing a defective turn signal switch.

5. Is it safe to continue driving with OBDII code B3949 triggered?

It is not recommended to drive with code B3949 triggered as it can affect the functionality of the right front turn signal, compromising your safety and potentially leading to a traffic violation.

6. How much does it typically cost to repair OBDII code B3949 at a repair shop?

The cost of repairing code B3949 at a repair shop can vary depending on the exact cause of the issue, but it may range from $50 to $200 for parts and labor.

7. Are there any preventative maintenance tips to avoid OBDII code B3949 in the future?

To prevent OBDII code B3949 in the future, it's advisable to regularly check and replace turn signal bulbs, inspect wiring for damage, and address any turn signal issues promptly.

8. Can extreme weather conditions affect the triggering of OBDII code B3949?

Yes, extreme weather conditions like heavy rain or snow can potentially cause water damage to the turn signal components, leading to issues that trigger code B3949.

9. Will resetting the OBDII system clear code B3949?

Resetting the OBDII system may temporarily clear code B3949, but if the underlying issue is not addressed and repaired, the code is likely to reappear once the problem is detected again.

10. How important is it to address OBDII code B3949 promptly?

It is crucial to address OBDII code B3949 promptly to ensure the proper functioning of the right front turn signal, maintain road safety, and avoid potential legal consequences for driving with a faulty turn signal.