AutoCodes – Chevrolet – B3948 2014 Chevrolet Silverado

B3948 2014 Chevrolet Silverado Code - Left Front Turn Signal Circuit

Quick Answer

Ground is applied at all times to the turn signal/multifunction switch. Common causes include Faulty Left Front Turn Signal Lamp, Left Front Turn Signal Lamp harness is open or shorted, Left 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: B3948 2014 Chevrolet Silverado indicates Left Front Turn Signal Circuit.
Common causes: Common causes include Faulty Left Front Turn Signal Lamp, Left Front Turn Signal Lamp harness is open or shorted, Left 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 183

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 B3948 2014 Chevrolet Silverado 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 B3948 2014 Chevrolet Silverado - Left Front Turn Signal Circuit - AutoCodes.com — B3948 2014 Chevrolet Silverado Code - Left Front Turn Signal Circuit

What does this mean?

What are the Possible Causes of the DTC B3948 2014 Chevrolet Silverado?

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

How to Fix the DTC B3948 2014 Chevrolet Silverado?

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 B3948 2014 Chevrolet Silverado 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 B3948 2014 Chevrolet Silverado code?

Need more information on how to fix the B3948 2014 Chevrolet Silverado code? Get Access to Factory Service Manuals

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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 B3948 2014 Chevrolet Silverado Code

1. What does OBDII code B3948 mean on a 2014 Chevrolet Silverado?

Code B3948 indicates an issue with the Left Front Turn Signal Circuit, typically involving a malfunction or interruption in the electrical connection.

2. What are the common symptoms of code B3948 in a 2014 Chevy Silverado?

Symptoms may include the left front turn signal not functioning, rapid or irregular blinking, or a dashboard warning light for turn signal failure.

3. What can cause code B3948 in a Chevrolet Silverado?

Common causes include a burned-out turn signal bulb, damaged wiring, corroded connectors, or a faulty turn signal socket.

4. How can I diagnose the B3948 code on my Silverado?

Start by visually inspecting the left front turn signal bulb, socket, and wiring for damage. Use a multimeter to check for proper voltage and continuity in the circuit.

5. Can a bad bulb trigger code B3948 on a 2014 Chevy Silverado?

Yes, a burned-out or improperly installed bulb can interrupt the circuit and trigger this code.

6. How do I fix code B3948 in my Silverado?

Replace the left front turn signal bulb if it's burned out, repair or replace damaged wiring, clean corroded connectors, or replace the turn signal socket if necessary.

7. Will code B3948 cause other electrical issues in my Silverado?

Typically, this code only affects the left front turn signal circuit, but unresolved issues may lead to broader electrical problems over time.

8. How much does it cost to repair a B3948 code on a Chevrolet Silverado?

Costs vary depending on the issue, but replacing a bulb or socket is relatively inexpensive, while wiring repairs may cost more if extensive damage exists.

9. Can I still drive my Silverado with code B3948 active?

You can drive the vehicle, but a malfunctioning turn signal is a safety hazard and may be illegal in some areas, so prompt repairs are recommended.

10. Do I need special tools to fix the B3948 code in my Silverado?

Basic tools like a screwdriver, multimeter, and electrical cleaner are sufficient for most repairs, but advanced diagnostics may require specialized equipment.