AutoCodes – Generic – B3949:02

B3949:02 Code - Right Front Turn Signal Circuit Short to Ground

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: B3949:02 indicates Right Front Turn Signal Circuit Short to Ground.
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 225

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 B3949:02 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 ground in the right front turn signal control circuit.

OBDII Code B3949:02 - Right Front Turn Signal Circuit Short to Ground - AutoCodes.com — B3949:02 Code - Right Front Turn Signal Circuit Short to Ground

What does this mean?

What are the Possible Causes of the DTC B3949:02?

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 B3949:02?

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 B3949:02 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 B3949:02 Code

1. What does the OBDII code B3949:02 mean?

The code B3949:02 indicates a Right Front Turn Signal Circuit Short to Ground, meaning there is an electrical issue causing the circuit to improperly connect to ground.

2. What are the symptoms of code B3949:02?

Common symptoms include the right front turn signal not working, rapid flashing of other turn signal lights, or a dashboard warning related to the turn signal system.

3. What causes the B3949:02 code?

The code is typically caused by damaged wiring, a corroded or shorted bulb socket, or a faulty turn signal bulb in the right front signal circuit.

4. Can a faulty turn signal bulb trigger code B3949:02?

Yes, a damaged or shorted turn signal bulb can cause this code by creating an unintended ground connection in the circuit.

5. How can I diagnose the B3949:02 code?

Start by inspecting the right front turn signal bulb, socket, and wiring for visible damage, corrosion, or exposed wires that might be causing a short to ground.

6. Is it safe to drive with code B3949:02?

While the car may still be operable, driving with a malfunctioning turn signal can be unsafe and may violate traffic laws. Prompt repair is recommended.

7. How do I fix code B3949:02?

Repair typically involves replacing a damaged turn signal bulb or socket, repairing or replacing damaged wiring, and ensuring proper insulation to prevent grounding issues.

8. Can a damaged bulb socket cause code B3949:02?

Yes, a corroded or shorted bulb socket can create a direct ground connection, triggering the B3949:02 code.

9. Do I need special tools to fix code B3949:02?

Basic tools like a multimeter to check for continuity and electrical shorts are helpful, but most repairs involve simple bulb or wiring replacements.

10. Will clearing the code without repairs fix the issue?

No, clearing the code without addressing the underlying cause will not resolve the issue. The code will likely reappear until the electrical problem is fixed.