AutoCodes – Chevrolet – B3950 Chevrolet

B3950 Chevrolet Code - Left Rear Turn Signal Circuit

Quick Answer

Ground is applied at all times to the turn signal/multifunction switch. Common causes include Faulty Left Rear Turn Signal Lamp, Left Rear Turn Signal Lamp harness is open or shorted, Left 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: B3950 Chevrolet indicates Left Rear Turn Signal Circuit.
Common causes: Common causes include Faulty Left Rear Turn Signal Lamp, Left Rear Turn Signal Lamp harness is open or shorted, Left 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 10,138

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 B3950 Chevrolet 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 left rear turn signal control circuit.

OBDII Code B3950 Chevrolet - Left Rear Turn Signal Circuit - AutoCodes.com — B3950 Chevrolet Code - Left Rear Turn Signal Circuit

What does this mean?

What are the Possible Causes of the DTC B3950 Chevrolet?

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

How to Fix the DTC B3950 Chevrolet?

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

B3950:01 Left Rear Turn Signal Circuit Short to Battery
B3950:02 Left Rear Turn Signal Circuit Short to Ground
B3950:04 Left Rear Turn Signal Circuit Open

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B3950 Chevrolet 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 B3950 Chevrolet code?

Need more information on how to fix the B3950 Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B3950 Chevrolet code diagnosed by a professional: Find a repair shop in your area

Information for Specific Chevrolet Models

B3950 2014 Chevrolet Silverado — Left Rear Turn Signal Circuit
B3950 2015 Chevrolet Silverado — Left Rear Turn Signal Circuit
B3950 2016 Chevrolet Silverado — Left Rear Turn Signal Circuit
B3950 2017 Chevrolet Silverado — Left Rear Turn Signal Circuit
B3950 2018 Chevrolet Silverado — Left Rear 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 B3950 Chevrolet Code

1. What are the common symptoms of OBDII code B3950 in a Chevrolet related to the Left Rear Turn Signal Circuit?

The common symptoms include the left rear turn signal not functioning properly, such as blinking rapidly or not illuminating at all.

2. What are the possible causes of OBDII code B3950 in a Chevrolet related to the Left Rear Turn Signal Circuit?

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

3. How can I diagnose the issue with the Left Rear Turn Signal Circuit in my Chevrolet when OBDII code B3950 is triggered?

You can start by visually inspecting the left rear turn signal bulb and the wiring connections. Testing the turn signal switch and using a multimeter to check for continuity in the circuit can help pinpoint the problem.

4. Are there any quick repair tips for resolving OBDII code B3950 in a Chevrolet related to the Left Rear Turn Signal Circuit?

If the issue is with the bulb, replacing it with a new one may solve the problem. Also, checking and repairing any damaged wiring or connectors can help restore the turn signal function.

5. Can a DIY enthusiast without advanced automotive skills fix OBDII code B3950 in a Chevrolet related to the Left Rear Turn Signal Circuit?

Yes, simple tasks like replacing a bulb or repairing a broken wire can often be done by DIY enthusiasts with basic tools and some guidance from repair manuals or online resources.

6. Is it safe to continue driving my Chevrolet when OBDII code B3950 is present, affecting the Left Rear Turn Signal Circuit?

It is not recommended to drive with a malfunctioning turn signal, as it can compromise the safety of your vehicle and increase the risk of accidents. Promptly addressing the issue is crucial.

7. How much should I expect to pay for professional repairs of OBDII code B3950 in a Chevrolet related to the Left Rear Turn Signal Circuit?

The cost of repairs can vary depending on the exact cause of the issue and the labor rates in your area. It's advisable to get estimates from certified mechanics or dealerships.

8. Will resetting the OBDII code B3950 in my Chevrolet resolve the Left Rear Turn Signal Circuit problem permanently?

Resetting the code may temporarily turn off the warning light, but it will not fix the underlying issue causing the Left Rear Turn Signal Circuit malfunction. Proper diagnosis and repair are necessary for a permanent solution.

9. Can extreme weather conditions or environmental factors trigger OBDII code B3950 in a Chevrolet related to the Left Rear Turn Signal Circuit?

While not a common cause, exposure to moisture, corrosion, or physical damage due to environmental factors can contribute to turn signal circuit problems. Regular vehicle maintenance can help prevent such issues.

10. Are there any recalls or service bulletins related to OBDII code B3950 in Chevrolet vehicles concerning the Left Rear Turn Signal Circuit?

It's advisable to check with Chevrolet dealerships or online databases for any relevant recalls or service bulletins addressing issues with the Left Rear Turn Signal Circuit that may be associated with OBDII code B3950.