AutoCodes – Generic – B3142

B3142 Code - Left Front Unlock Switch Circuit Low

Quick Answer

The switch that failed and generated the Diagnostic Trouble Code (DTC) is wired to either the Driver Door Switch Assembly (DDSA) or the Passenger Front Door Module (PDM). Common causes include Faulty Left Front Power Door Lock Switch, Left Front Power Door Lock Switch harness is open or shorted, Left Front Power Door Lock 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: B3142 indicates Left Front Unlock Switch Circuit Low.
Common causes: Common causes include Faulty Left Front Power Door Lock Switch, Left Front Power Door Lock Switch harness is open or shorted, Left Front Power Door Lock 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 1,025

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 04, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B3142 Description

The switch that failed and generated the Diagnostic Trouble Code (DTC) is wired to either the Driver Door Switch Assembly (DDSA) or the Passenger Front Door Module (PDM). When a door lock switch is activated to the Lock or Unlock function, the DDSA or PDM receives the switch input and sends the information on, via the Serial Data Class 2 communications line, to the Rear Integration Module (RIM), which is the master of all lock operations. If the RIM determines that the message is a valid request and conditions are correct for a door lock function to occur, it sends its OK back to all the door modules to Lock or Unlock the doors. Each door module supplies power and ground to its associated lock actuator to Lock or Unlock the associated door.

OBDII Code B3142 - Left Front Unlock Switch Circuit Low - AutoCodes.com — B3142 Code - Left Front Unlock Switch Circuit Low

What does this mean?

What are the Possible Causes of the DTC B3142?

Faulty Left Front Power Door Lock Switch
Left Front Power Door Lock Switch harness is open or shorted
Left Front Power Door Lock Switch circuit poor electrical connection
Faulty Driver Door Switch Assembly (DDSA)

How to Fix the DTC B3142?

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 B3142 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 B3142 code?

Need more information on how to fix the B3142 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B3142 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B3142 Buick — Left Front Unlock Switch Circuit Low
B3142 Cadillac — Left Front Unlock Switch Circuit Low
B3142 Chevrolet — Left Front Unlock Switch Circuit Low
B3142 GMC — Left Front Unlock Switch Circuit Low

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 B3142 Code

1. What are the common symptoms of OBDII code B3142 (Left Front Unlock Switch Circuit Low)?

The common symptoms of OBDII code B3142 include difficulty unlocking the left front door using the switch, unresponsive left front door unlock function, and potential issues with the central locking system.

2. What are the possible causes of OBDII code B3142?

Possible causes of OBDII code B3142 include a faulty left front unlock switch, damaged wiring or connectors in the circuit, a malfunctioning door control module, or a problem with the central locking system.

3. How can I diagnose the cause of OBDII code B3142?

To diagnose the cause of OBDII code B3142, you can start by inspecting the left front unlock switch and its wiring for any visible damage. You can also use a multimeter to test the switch's functionality and check for continuity in the circuit.

4. What are some repair tips for OBDII code B3142?

Repair tips for OBDII code B3142 may include replacing the left front unlock switch if it is found to be faulty, repairing or replacing damaged wiring or connectors in the circuit, checking and repairing any issues with the door control module, and ensuring proper operation of the central locking system.

5. Can OBDII code B3142 affect other systems in the vehicle?

While OBDII code B3142 specifically relates to the left front unlock switch circuit, it can potentially affect the overall functionality of the central locking system in the vehicle. It is important to address this code promptly to prevent any further issues with door locking and unlocking.

6. Is it safe to continue driving with OBDII code B3142 present?

It is generally safe to continue driving with OBDII code B3142, as it primarily affects the left front door unlock switch circuit. However, it is recommended to address the issue promptly to ensure proper functioning of the door locking system and overall vehicle security.

7. Can OBDII code B3142 be reset without repairs?

While you can clear OBDII codes using a diagnostic scanner, it is not recommended to reset OBDII code B3142 without addressing the underlying issue. Resetting the code without making necessary repairs may lead to recurring problems with the left front door unlock function.

8. How much does it typically cost to repair OBDII code B3142?

The cost of repairing OBDII code B3142 can vary depending on the specific cause of the issue. Costs may include the price of a new left front unlock switch, wiring repairs, labor charges, and any additional components that need to be replaced. It is advisable to consult a professional for an accurate estimate.

9. Can weather conditions affect OBDII code B3142?

Extreme weather conditions, such as moisture or extreme temperatures, can potentially impact the electrical components involved in the left front unlock switch circuit. It is important to ensure proper insulation and protection of these components to prevent weather-related issues leading to OBDII code B3142.

10. How can I prevent OBDII code B3142 from occurring in the future?

To prevent OBDII code B3142 from occurring in the future, you can perform regular maintenance checks on the door unlock switches and related wiring, ensure proper insulation and protection of electrical components, and address any issues with the central locking system promptly.