AutoCodes – Chevrolet – B3128 Chevrolet

B3128 Chevrolet Code - Left Front/Driver Door Unlock Circuit High

Quick Answer

The outputs to the door lock actuators are controlled by the Body Control Module (BCM). Common causes include Faulty Inoperative Door Lock Actuator, Inoperative Door Lock Actuator harness is open or shorted, Inoperative Door Lock Actuator 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: B3128 Chevrolet indicates Left Front/Driver Door Unlock Circuit High.
Common causes: Common causes include Faulty Inoperative Door Lock Actuator, Inoperative Door Lock Actuator harness is open or shorted, Inoperative Door Lock Actuator 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 2,779

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code B3128 Chevrolet Description

The outputs to the door lock actuators are controlled by the Body Control Module (BCM). When the BCM receives a lock input from a door lock switch, or a keyless entry transmitter, it applies battery positive voltage to the door lock actuator lock control circuit, a ground to the door lock actuator unlock control, and the driver door lock actuator unlock control circuits. When the BCM receives an unlock input from a door lock switch, it applies battery positive voltage to the door lock actuator unlock control, the driver door lock actuator unlock control circuits, and a ground to the door lock actuator lock control circuit. When the BCM receives an single Unlock input from a keyless entry transmitter, it applies battery positive voltage to the driver door lock actuator unlock control circuit and a ground to the door lock actuator lock control circuit to unlock the driver door. A second Unlock input from the transmitter applies battery positive voltage to the door lock actuator unlock control circuit, and a ground to the door lock actuator lock control circuit to unlock the passenger doors.

OBDII Code B3128 Chevrolet - Left Front/Driver Door Unlock Circuit High - AutoCodes.com — B3128 Chevrolet Code - Left Front/Driver Door Unlock Circuit High

What does this mean?

What are the Possible Causes of the DTC B3128 Chevrolet?

Faulty Inoperative Door Lock Actuator
Inoperative Door Lock Actuator harness is open or shorted
Inoperative Door Lock Actuator circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B3128 Chevrolet?

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 B3128 Chevrolet 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 B3128 Chevrolet code?

Need more information on how to fix the B3128 Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B3128 Chevrolet 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 B3128 Chevrolet Code

1. What are the common symptoms of OBDII code B3128 Chevrolet (Left Front/Driver Door Unlock Circuit High)?

The common symptoms include the inability to unlock the left front/driver door using the remote keyless entry or interior door switch.

2. What can cause the OBDII code B3128 Chevrolet to trigger?

The code B3128 can be triggered by a malfunction in the left front/driver door unlock circuit, such as a wiring issue, faulty door lock actuator, or a problem with the door control module.

3. How can I diagnose the cause of OBDII code B3128 Chevrolet?

You can diagnose the cause of the code B3128 by inspecting the wiring harness, checking the door lock actuator for proper operation, and using a scan tool to communicate with the door control module for any error codes.

4. What are some possible repair tips for fixing OBDII code B3128 Chevrolet?

Repair tips for fixing the code B3128 may include repairing or replacing damaged wiring, replacing the faulty door lock actuator, or reprogramming the door control module if necessary.

5. Can OBDII code B3128 Chevrolet affect other vehicle systems?

While the code B3128 specifically relates to the left front/driver door unlock circuit, it could potentially affect other systems connected to the door control module, such as interior lighting and security features.

6. Is it safe to continue driving with OBDII code B3128 Chevrolet present?

It is generally safe to continue driving with the code B3128 present, but it is recommended to address the issue promptly to ensure proper operation of the left front/driver door lock and unlock functions.

7. How much does it typically cost to repair OBDII code B3128 Chevrolet?

The cost to repair the code B3128 can vary depending on the exact cause of the issue, but it may range from $100 to $300 for parts and labor.

8. Can I reset OBDII code B3128 Chevrolet without fixing the underlying issue?

While you can clear the code temporarily, it will likely return until the underlying issue with the left front/driver door unlock circuit is addressed and repaired.

9. Are there any preventive measures to avoid OBDII code B3128 Chevrolet in the future?

To prevent the recurrence of the code B3128, regular inspection of the door lock system and immediate repair of any wiring issues or component failures is recommended.

10. Can a DIY enthusiast fix OBDII code B3128 Chevrolet at home?

Depending on your skill level and access to tools, DIY enthusiasts may be able to diagnose and repair the code B3128 at home, especially for simpler tasks like checking wiring connections or replacing the door lock actuator.