B3950 2018 GMC Sierra Code - Left Rear Turn Signal Circuit
Quick Answer
The B3950 diagnostic trouble code (DTC) for the 2018 GMC Sierra specifically refers to an issue with the left rear turn signal circuit. Common causes include Faulty turn signal bulb, Damaged wiring harness, Defective turn signal switch. 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
- B3950 2018 GMC Sierra indicates Left Rear Turn Signal Circuit.
- Common causes
- Common causes include Faulty turn signal bulb, Damaged wiring harness, Defective turn signal switch.
- 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 B3950 2018 GMC Sierra Description
The B3950 diagnostic trouble code (DTC) for the 2018 GMC Sierra specifically refers to an issue with the left rear turn signal circuit. This code indicates that there is a malfunction or fault in the electrical system that controls the left rear turn signal on the vehicle. The turn signal circuit is a crucial component of the vehicle's lighting system, responsible for indicating to other drivers on the road when the vehicle is turning or changing lanes. When this circuit is not functioning properly, it can pose a safety hazard as it affects the visibility of the vehicle to other drivers.
Common Causes of B3950 2018 GMC Sierra
- Faulty turn signal bulb
- Damaged wiring harness
- Defective turn signal switch
- Blown fuse or relay in the turn signal circuit
- Corrosion or poor connection in the electrical system
Symptoms of B3950 2018 GMC Sierra
- Left rear turn signal not illuminating
- Rapid or erratic flashing of the left rear turn signal
- Left rear turn signal staying on constantly
- Turn signal indicator on the dashboard flashing rapidly
How to Fix B3950 2018 GMC Sierra
- Begin by visually inspecting the left rear turn signal bulb for any signs of damage or burnout. Replace the bulb if necessary.
- Check the wiring harness for any visible damage or corrosion. Repair or replace the wiring as needed.
- Test the turn signal switch for proper functionality. Replace the switch if it is faulty.
- Inspect the fuses and relays related to the turn signal circuit. Replace any blown fuses or faulty relays.
- Ensure all connections in the left rear turn signal circuit are secure and free of corrosion.
Cost to Fix B3950 2018 GMC Sierra
The cost of repairing the left rear turn signal circuit can vary depending on the specific cause of the issue and the labor rates in your area. On average, the parts for this repair, including a new turn signal bulb, wiring harness, turn signal switch, fuses, and relays, can range from $50 to $200. Labor costs can add an additional $100 to $300, depending on the complexity of the repair and the hourly rates of the auto repair shop. Overall, the total cost for resolving the B3950 code for the left rear turn signal circuit could range from $150 to $500. It is advisable to obtain quotes from multiple repair shops to ensure you are getting a fair price for the repair.
Tech Notes for B3950 2018 GMC Sierra
B3950:02 Left Rear Turn Signal Circuit Short to Ground
B3950:04 Left Rear Turn Signal Circuit Open
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Frequently Asked Questions about B3950 2018 GMC Sierra Code
1. What are the common symptoms of OBDII code B3950 in a 2018 GMC Sierra related to the Left Rear Turn Signal Circuit?
The common symptoms include the left rear turn signal not working, fast blinking of the turn signal indicator on the dashboard, or a warning message displayed on the instrument cluster.
2. What are the possible causes of OBDII code B3950 in a 2018 GMC Sierra?
Possible causes of this code could be a faulty left rear turn signal bulb, a damaged wiring harness, a malfunctioning turn signal switch, or a problem with the body control module.
3. How can I diagnose the issue with the Left Rear Turn Signal Circuit in a 2018 GMC Sierra?
You can start by visually inspecting the left rear turn signal bulb and its connection. Check for any visible damage to the wiring harness. Using a multimeter, test the continuity of the circuit and check for any voltage drops.
4. Can I repair OBDII code B3950 in a 2018 GMC Sierra on my own?
Depending on your level of automotive experience, you may be able to replace a faulty bulb or repair a damaged wire on your own. However, more complex issues involving the electrical system or modules may require professional diagnosis and repair.
5. What are some tips for fixing OBDII code B3950 in a 2018 GMC Sierra?
Ensure you use the correct replacement bulb for the left rear turn signal. Properly secure any repaired wiring connections to prevent future issues. Clear the trouble codes after completing the repair to reset the system.
6. Is it safe to drive my 2018 GMC Sierra with OBDII code B3950 related to the Left Rear Turn Signal Circuit?
It is not recommended to drive the vehicle with a malfunctioning turn signal, as it compromises road safety. Other drivers may not be able to anticipate your turns or lane changes, increasing the risk of accidents.
7. How much does it typically cost to repair OBDII code B3950 in a 2018 GMC Sierra?
The cost of repair can vary depending on the specific issue causing the code. Replacing a turn signal bulb is relatively inexpensive, while repairing or replacing a damaged wiring harness or module can be more costly. Consult a mechanic for an accurate estimate.
8. Can extreme weather conditions affect the Left Rear Turn Signal Circuit in a 2018 GMC Sierra?
Yes, extreme weather conditions such as heavy rain or snow can cause water damage to the wiring harness or connectors, leading to electrical issues and triggering OBDII code B3950. It's essential to protect the electrical components from exposure to harsh elements.
9. Will resetting the vehicle's battery clear OBDII code B3950 in a 2018 GMC Sierra?
Resetting the battery may temporarily clear the code, but it will likely reappear if the underlying issue with the Left Rear Turn Signal Circuit is not addressed. It's important to diagnose and repair the root cause of the problem to prevent the code from returning.
10. How can I prevent OBDII code B3950 from recurring in my 2018 GMC Sierra in the future?
Regularly inspect and maintain the vehicle's lighting system, including the turn signals, to ensure they are functioning properly. Address any issues promptly to prevent further damage to the electrical components and avoid triggering the code again.
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