AutoCodes – Buick – B3806 Buick

B3806 Buick Code - High Beam and Headlamp Flash Select Circuit Malfunction

Quick Answer

When the turn signal/multifunction switch is momentarily placed in the flash-to-pass position, ground is applied to the Body Control Module (BCM) through the flash-to-pass signal circuit. Common causes include Faulty Turn Signal/Multifunction Switch, Turn Signal/Multifunction Switch harness is open or shorted, Turn Signal/Multifunction Switch 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: B3806 Buick indicates High Beam and Headlamp Flash Select Circuit Malfunction.
Common causes: Common causes include Faulty Turn Signal/Multifunction Switch, Turn Signal/Multifunction Switch harness is open or shorted, Turn Signal/Multifunction Switch 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 547

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 14, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B3806 Buick Description

When the turn signal/multifunction switch is momentarily placed in the flash-to-pass position, ground is applied to the Body Control Module (BCM) through the flash-to-pass signal circuit. The BCM responds to the flash-to-pass request by applying ground to the high-beam relay control circuit which energizes the high-beam relay. With the high beam relay energized, the switch contacts close allowing battery voltage to flow through the high beam fuses to the high beam control circuits illuminating the high beam headlamps. The high beam headlamps will only illuminate for as long as the flash-to-pass switch is activated. The Diagnostic Trouble Code (DTC) sets when the BCM detects a short to ground in the turn signal/multifunction switch flash to pass signal circuit.

OBDII Code B3806 Buick - High Beam and Headlamp Flash Select Circuit Malfunction - AutoCodes.com — B3806 Buick Code - High Beam and Headlamp Flash Select Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC B3806 Buick?

Faulty Turn Signal/Multifunction Switch
Turn Signal/Multifunction Switch harness is open or shorted
Turn Signal/Multifunction Switch circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B3806 Buick?

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 B3806 Buick 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 B3806 Buick Code

1. What are the common symptoms of OBDII code B3806 Buick (High Beam and Headlamp Flash Select Circuit Malfunction)?

The common symptoms include high beam headlights not working, inability to switch between high and low beams, and the headlamp flash function not functioning properly.

2. What are the possible causes of OBDII code B3806 Buick?

Possible causes include a faulty headlamp flash select switch, wiring issues in the high beam circuit, a malfunctioning high beam relay, or a problem with the body control module.

3. How can I diagnose OBDII code B3806 Buick?

Diagnosing this code typically involves checking the headlamp flash select switch for proper operation, inspecting the wiring and connectors in the high beam circuit, testing the high beam relay, and scanning the body control module for any related trouble codes.

4. Can I still drive my vehicle with OBDII code B3806 Buick?

It is generally safe to drive with this code as long as your low beam headlights are working properly. However, it is recommended to address the issue promptly to ensure your high beam headlights are functioning correctly for optimal visibility at night.

5. How can I repair OBDII code B3806 Buick?

Repairing this code may involve replacing the headlamp flash select switch, repairing any damaged wiring or connectors in the high beam circuit, replacing a faulty high beam relay, or addressing any issues with the body control module as needed.

6. Is it possible to reset OBDII code B3806 Buick?

Resetting the code may temporarily turn off the warning light, but it is recommended to diagnose and repair the underlying issue causing the malfunction before resetting the code to prevent it from recurring.

7. Can a DIY enthusiast fix OBDII code B3806 Buick?

Depending on your skill level and access to tools, some DIY enthusiasts may be able to diagnose and repair this code. However, if you are not experienced with automotive electrical systems, it is best to consult a professional mechanic for assistance.

8. Will OBDII code B3806 Buick affect my vehicle's performance?

This code is related to the high beam and headlamp flash select circuit, so it should not significantly impact your vehicle's overall performance. However, it can affect your visibility at night if the high beams are not functioning correctly.

9. How much does it typically cost to repair OBDII code B3806 Buick?

The cost of repairing this code can vary depending on the specific cause of the malfunction and the labor rates in your area. It is advisable to get a diagnostic from a mechanic to receive an accurate estimate for the repair.

10. How can I prevent OBDII code B3806 Buick from occurring again in the future?

To prevent this code from recurring, it is essential to address any underlying issues promptly, perform regular maintenance on your vehicle's lighting system, and avoid overloading the electrical circuits by using proper wattage bulbs.