AutoCodes – Saturn – B3840 Saturn

B3840 Saturn Code - Park Lamp Signal Circuit Low

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: B3840 Saturn indicates Park Lamp Signal Circuit Low.
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 569

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
FAQs
Comments
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Code B3840 Saturn 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 an open or a short to ground in the park lamp supply voltage circuit with the headlamp switch in either the PARK position or the HEAD position.

OBDII Code B3840 Saturn - Park Lamp Signal Circuit Low - AutoCodes.com — B3840 Saturn Code - Park Lamp Signal Circuit Low

What does this mean?

What are the Possible Causes of the DTC B3840 Saturn?

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 B3840 Saturn?

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 B3840 Saturn 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 B3840 Saturn code?

Need more information on how to fix the B3840 Saturn code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B3840 Saturn code diagnosed by a professional: Find a repair shop in your area

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 B3840 Saturn Code

1. What are common symptoms of OBDII code B3840 in a Saturn related to the Park Lamp Signal Circuit Low?

- Common symptoms include dim or non-functional park lamps, warning lights on the dashboard, and potential issues with other exterior lighting.

2. What are possible causes of the Park Lamp Signal Circuit Low OBDII code in a Saturn?

- Causes can include faulty wiring or connectors in the park lamp circuit, a defective park lamp switch, or a malfunctioning body control module.

3. How can I diagnose the Park Lamp Signal Circuit Low code in my Saturn?

- Use a diagnostic scanner to read the OBDII code, inspect the park lamp wiring and connectors for damage, and test the park lamp switch and body control module for proper functionality.

4. Can I still drive my Saturn with the B3840 OBDII code?

- It is generally safe to drive the vehicle with this code, but it is important to address the underlying issue promptly to ensure proper lighting function for safety.

5. How do I repair the Park Lamp Signal Circuit Low code in my Saturn?

- Repair methods can include repairing or replacing damaged wiring, cleaning or replacing connectors, replacing the park lamp switch, or reprogramming the body control module.

6. Are there any DIY tips for fixing the B3840 code in a Saturn?

- DIY enthusiasts with automotive experience can start by checking fuses related to the park lamps, inspecting the wiring visually for any obvious issues, and testing the park lamp switch for continuity.

7. Can a faulty body control module cause the B3840 code in a Saturn?

- Yes, a malfunctioning body control module can result in the Park Lamp Signal Circuit Low code due to its role in controlling various vehicle lighting functions.

8. Will resetting the OBDII code make the issue go away permanently?

- Resetting the code may temporarily clear the warning lights, but if the underlying issue causing the B3840 code is not fixed, the code will likely reappear.

9. How much does it typically cost to repair the Park Lamp Signal Circuit Low code in a Saturn?

- The cost of repair can vary depending on the specific cause of the issue, but it may range from $100 to $300 for parts and labor.

10. Is it necessary to visit a mechanic for the B3840 OBDII code, or can I fix it myself?

- While some DIY enthusiasts may be able to diagnose and repair the issue themselves, others may prefer to consult a qualified mechanic for a thorough inspection and professional repair.