AutoCodes – Generic – B051A

B051A Code - Left Side Assist Step Motor Control Circuit

Quick Answer

The Assist Step Control (ASC) Module controls the running board actuators to extend or retract the running boards. Common causes include Faulty Left Side Assist Step Motor, Left Side Assist Step Motor harness is open or shorted, Left Side Assist Step Motor circuit poor electrical connection. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means: B051A indicates Left Side Assist Step Motor Control Circuit.
Common causes: Common causes include Faulty Left Side Assist Step Motor, Left Side Assist Step Motor harness is open or shorted, Left Side Assist Step Motor circuit poor electrical connection.
Severity: Low - monitor the vehicle and repair when practical.
Can I drive?: The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

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Code Popularity 1,596

How popular is this code, among other codes? Low

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Nov 13, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code B051A Description

The Assist Step Control (ASC) Module controls the running board actuators to extend or retract the running boards. Each actuator consists of an electric motor and a potentiometer. The module supplies a low reference and 10-volt reference source voltage to the potentiometer. The ASC control module monitors the voltage drop across the potentiometer on the position signal circuit. When the actuator shaft rotates, the voltage on the position signal circuit changes. The ASC control module supplies the actuator motor with a 12-volt control circuit and a ground control circuit. The ASC module controls the direction of the actuator by changing the polarity of the control circuits.

OBDII Code B051A - Left Side Assist Step Motor Control Circuit - AutoCodes.com — B051A Code - Left Side Assist Step Motor Control Circuit

What does this mean?

What are the Possible Causes of the DTC B051A?

Faulty Left Side Assist Step Motor
Left Side Assist Step Motor harness is open or shorted
Left Side Assist Step Motor circuit poor electrical connection
Faulty Assist Step Control (ASC) Module

How to Fix the DTC B051A?

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

B051A:0B Left Side Assist Step Motor Control Circuit Current Above Threshold
B051A:01 Left Side Assist Step Motor Control Circuit Short to Battery
B051A:02 Left Side Assist Step Motor Control Circuit Short to Ground
B051A:04 Left Side Assist Step Motor Control Circuit Open Circuit

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B051A 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

B051A Buick — Left Side Assist Step Motor Control Circuit
B051A Cadillac — Left Side Assist Step Motor Control Circuit
B051A Chevrolet — Left Side Assist Step Motor Control Circuit
B051A GMC — Left Side Assist Step Motor Control 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 B051A Code

1. What are common symptoms of OBDII code B051A (Left Side Assist Step Motor Control Circuit)?

- Common symptoms include malfunctioning left side assist step, inability to extend or retract the step, and illuminated warning lights on the dashboard.

2. What are possible causes of OBDII code B051A?

- The code B051A can be triggered by a faulty left side assist step motor, damaged wiring or connectors in the control circuit, or a malfunctioning control module.

3. How can I diagnose the cause of OBDII code B051A?

- Diagnose the code by checking the left side assist step motor for proper operation, inspecting the wiring and connectors for damage, and using a scan tool to read the control module data.

4. Is it safe to drive with OBDII code B051A present?

- It is generally safe to drive with this code, but it is recommended to address the issue promptly to ensure the proper operation of the left side assist step.

5. Can I repair OBDII code B051A on my own?

- Repairing OBDII code B051A may require specialized tools and knowledge, so it is recommended to consult a professional mechanic for accurate diagnosis and repair.

6. How much does it typically cost to repair OBDII code B051A?

- The cost of repairing OBDII code B051A can vary depending on the exact cause of the issue, but it may involve replacing the left side assist step motor, repairing wiring, or reprogramming the control module.

7. Are there any preventive maintenance tips to avoid OBDII code B051A?

- Regularly inspecting and maintaining the left side assist step system, including checking for any signs of damage or malfunction, can help prevent OBDII code B051A from occurring.

8. Can OBDII code B051A affect other vehicle systems?

- While OBDII code B051A specifically relates to the left side assist step motor control circuit, it may cause issues with related systems such as the power running boards or vehicle stability control.

9. How urgent is it to address OBDII code B051A?

- While OBDII code B051A may not pose an immediate safety risk, it is recommended to address the issue promptly to ensure the proper functioning of the left side assist step and related systems.

10. Can resetting the OBDII system clear code B051A?

- Resetting the OBDII system may temporarily clear the code B051A, but if the underlying issue is not addressed, the code is likely to reappear. It is best to diagnose and repair the root cause of the code.