AutoCodes – Buick – B3841 Buick

B3841 Buick Code - Park Lamp Signal Circuit High

Quick Answer

The Body Control Module (BCM) monitors the activity of the park lamp relay switch with the headlamp switch in either the PARK position or the HEAD position. Common causes include Faulty Park Lamp Relay, Park Lamp Relay harness is open or shorted, Park Lamp Relay 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: B3841 Buick indicates Park Lamp Signal Circuit High.
Common causes: Common causes include Faulty Park Lamp Relay, Park Lamp Relay harness is open or shorted, Park Lamp Relay 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 709

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 Mar 23, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code B3841 Buick Description

The Body Control Module (BCM) monitors the activity of the park lamp relay switch with the headlamp switch in either the PARK position or the HEAD position. The Diagnostic Trouble Code (DTC) sets when the BCM detects a short to voltage in the park lamp supply voltage circuit when the headlamp switch is in the OFF position.

OBDII Code B3841 Buick - Park Lamp Signal Circuit High - AutoCodes.com — B3841 Buick Code - Park Lamp Signal Circuit High

What does this mean?

What are the Possible Causes of the DTC B3841 Buick?

Faulty Park Lamp Relay
Park Lamp Relay harness is open or shorted
Park Lamp Relay circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B3841 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 B3841 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.