AutoCodes – Generic – B3140

B3140 Code - Driver Door Unlock Switch Circuit

Quick Answer

The Body Control Module (BCM) monitors the voltage level of the door lock and door unlock signal circuits. Common causes include Faulty Driver Door Unlock Switch, Driver Door Unlock Switch harness is open or shorted, Driver Door Unlock 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: B3140 indicates Driver Door Unlock Switch Circuit.
Common causes: Common causes include Faulty Driver Door Unlock Switch, Driver Door Unlock Switch harness is open or shorted, Driver Door Unlock 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 2,187

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 11, 2023

Description
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
FAQs
Comments
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Code B3140 Description

The Body Control Module (BCM) monitors the voltage level of the door lock and door unlock signal circuits. When the driver door lock switch is in the open position, the voltage level in the signal circuit will be near 12 V. When the driver door lock switch is pressed to the lock or unlock position, the voltage level in the appropriate signal circuit will drop to 0 V and the BCM will detect the voltage drop and command the door latches to perform the requested lock or unlock command. The Diagnostic Trouble Code (DTC) will be set when the BCM detects a short to ground in the switch circuit.

OBDII Code B3140 - Driver Door Unlock Switch Circuit - AutoCodes.com — B3140 Code - Driver Door Unlock Switch Circuit

What does this mean?

What are the Possible Causes of the DTC B3140?

Faulty Driver Door Unlock Switch
Driver Door Unlock Switch harness is open or shorted
Driver Door Unlock Switch circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B3140?

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

User Submitted Video

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B3140 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 B3140 code?

Need more information on how to fix the B3140 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B3140 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B3140 Buick — Driver Door Unlock Switch Circuit
B3140 Cadillac — Driver Door Unlock Switch Circuit
B3140 Chevrolet — Driver Door Unlock Switch Circuit
B3140 GMC — Driver Door Unlock Switch 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 B3140 Code

1. What are the common symptoms of OBDII code B3140 related to the driver door unlock switch circuit?

- The common symptoms include the inability to unlock the driver door using the switch, erratic behavior of the door lock system, or the door not unlocking at all.

2. What are the possible causes of OBDII code B3140 related to the driver door unlock switch circuit?

- The code B3140 can be caused by a malfunctioning driver door unlock switch, damaged wiring or connectors in the circuit, or a faulty door lock actuator.

3. How can I diagnose the issue causing OBDII code B3140 related to the driver door unlock switch circuit?

- You can start by checking the driver door unlock switch for proper functionality, inspecting the wiring and connectors for any damage, and testing the door lock actuator for proper operation.

4. What are some repair tips for fixing OBDII code B3140 related to the driver door unlock switch circuit?

- Repair tips include repairing or replacing the driver door unlock switch if faulty, repairing any damaged wiring or connectors, and replacing the door lock actuator if necessary.

5. Can OBDII code B3140 related to the driver door unlock switch circuit be fixed without professional help?

- Depending on your level of automotive repair experience, you may be able to fix the issue yourself by following diagnostic procedures and repair tips. However, if you are unsure, it's recommended to seek professional help.

6. Is it safe to continue driving with OBDII code B3140 related to the driver door unlock switch circuit?

- While the code itself may not affect the drivability of the vehicle, it can lead to inconvenience and potential safety issues if the driver door cannot be unlocked properly. It's best to address the issue promptly.

7. Can a faulty driver door unlock switch cause other related issues in the vehicle?

- Yes, a faulty driver door unlock switch can potentially cause issues with the entire door lock system, affecting the security and convenience of accessing the vehicle.

8. Are there any preventive measures to avoid OBDII code B3140 related to the driver door unlock switch circuit?

- Regularly inspecting and maintaining the driver door unlock switch, wiring, and connectors can help prevent issues that may trigger OBDII code B3140.

9. How much does it typically cost to repair OBDII code B3140 related to the driver door unlock switch circuit?

- The cost of repair can vary depending on the specific cause of the issue, parts needed, and labor costs. It's recommended to get a diagnostic from a professional to determine the exact cost.

10. Can resetting the OBDII system clear OBDII code B3140 related to the driver door unlock switch circuit?

- Resetting the OBDII system may temporarily clear the code, but it will likely reappear if the underlying issue causing OBDII code B3140 is not addressed and fixed.