AutoCodes – Generic – B3125

B3125 Code - Driver Door Only Unlock Circuit

Quick Answer

The Body Control Module (BCM) supplies a 12-volt signal to the lock and unlock signal circuits of the driver and passenger door lock switches. Common causes include Faulty Driver Door Latch Assembly, Driver Door Latch Assembly harness is open or shorted, Driver Door Latch Assembly 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: B3125 indicates Driver Door Only Unlock Circuit.
Common causes: Common causes include Faulty Driver Door Latch Assembly, Driver Door Latch Assembly harness is open or shorted, Driver Door Latch Assembly 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 4,500

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 B3125 Description

The Body Control Module (BCM) supplies a 12-volt signal to the lock and unlock signal circuits of the driver and passenger door lock switches. When the appropriate switch is pressed, a contact within the door lock switch closes providing a ground path for the signal circuit. The BCM will detect the voltage drop in the signal and will command the doors to perform the lock or unlock functions. The BCM may also receive a LOCK or UNLOCK command from the Keyless Entry Control Module.
The BCM, upon receipt of a lock switch lock or unlock signal, will supply voltage to the door lock actuator lock or unlock control circuits. Since the opposite side of the lock actuator is connected to the ground through the other lock actuator control circuit, the doors will then lock or unlock as commanded. The Diagnostic Trouble Code (DTC) sets when the BCM detects a short to ground or open/high resistance on a door latch control circuit.

OBDII Code B3125 - Driver Door Only Unlock Circuit - AutoCodes.com — B3125 Code - Driver Door Only Unlock Circuit

What does this mean?

What are the Possible Causes of the DTC B3125?

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

How to Fix the DTC B3125?

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 B3125 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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Information for Specific Makes

B3125 Buick — Driver Door Only Unlock Circuit
B3125 Cadillac — Driver Door Only Unlock Circuit
B3125 Chevrolet — Driver Door Only Unlock Circuit
B3125 GMC — Driver Door Only Unlock 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 B3125 Code

1. What are the common symptoms of OBDII code B3125 (Driver Door Only Unlock Circuit)?

The common symptoms of OBDII code B3125 include the driver door not unlocking when using the key fob or the interior door unlock button.

2. What are the possible causes of OBDII code B3125 (Driver Door Only Unlock Circuit)?

Possible causes of OBDII code B3125 include a faulty driver door lock actuator, a broken wire in the driver door harness, or a malfunctioning door control module.

3. How can I diagnose the issue related to OBDII code B3125 (Driver Door Only Unlock Circuit)?

Diagnosing the issue related to OBDII code B3125 involves inspecting the driver door lock actuator, checking the wiring in the driver door harness, and testing the door control module for proper functioning.

4. Can I still drive my vehicle with OBDII code B3125 (Driver Door Only Unlock Circuit)?

Yes, you can still drive your vehicle with OBDII code B3125, but you may experience inconvenience in manually unlocking the driver door until the issue is resolved.

5. How can I repair OBDII code B3125 (Driver Door Only Unlock Circuit)?

To repair OBDII code B3125, you may need to replace the faulty driver door lock actuator, repair any broken wires in the driver door harness, or replace the malfunctioning door control module.

6. Are there any DIY tips for fixing OBDII code B3125 (Driver Door Only Unlock Circuit)?

DIY tips for fixing OBDII code B3125 include checking the door lock actuator connections, inspecting the door harness for visible damage, and testing the door control module using a multimeter.

7. Is OBDII code B3125 (Driver Door Only Unlock Circuit) a common issue in certain car models?

OBDII code B3125 related to the driver door only unlock circuit can be a common issue in vehicles that have power door locks and keyless entry systems.

8. Can weather conditions affect OBDII code B3125 (Driver Door Only Unlock Circuit)?

Extreme weather conditions such as heavy rain or snow can potentially cause issues with the driver door lock actuator or wiring, leading to OBDII code B3125.

9. Should I reset the OBDII code B3125 (Driver Door Only Unlock Circuit) after repairing the issue?

After repairing the issue related to OBDII code B3125, it is recommended to reset the code using an OBDII scanner to clear the fault code from the vehicle's memory.

10. How much does it typically cost to fix OBDII code B3125 (Driver Door Only Unlock Circuit)?

The cost to fix OBDII code B3125 can vary depending on the specific cause of the issue, but it may range from $100 to $300 for parts and labor at a repair shop.