AutoCodes – Generic – B051A:0B

B051A:0B Code - Left Side Assist Step Motor Control Circuit Current Above Threshold

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:0B indicates Left Side Assist Step Motor Control Circuit Current Above Threshold.
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 226

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:0B 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. The Diagnostic Trouble Code (DTC) will be set when the motor control circuits are shorted together.

OBDII Code B051A:0B - Left Side Assist Step Motor Control Circuit Current Above Threshold - AutoCodes.com — B051A:0B Code - Left Side Assist Step Motor Control Circuit Current Above Threshold

What does this mean?

What are the Possible Causes of the DTC B051A:0B?

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:0B?

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:0B 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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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:0B Code

1. What does the OBDII code B051A:0B mean?

The code B051A:0B indicates that the left side assist step motor control circuit has a current above the acceptable threshold, suggesting an electrical issue with the motor or its circuit.

2. What are the common symptoms of the B051A:0B code?

Symptoms may include the left side assist step not deploying or retracting properly, intermittent operation, or complete failure to respond.

3. What causes the B051A:0B code to appear?

Common causes include a short circuit, damaged assist step motor, corroded or loose wiring connections, or a malfunctioning control module.

4. Can I still drive with the B051A:0B code active?

Yes, you can still drive the vehicle, but the left side assist step may not function. This could pose a safety or convenience issue when entering or exiting the vehicle.

5. How do I diagnose the B051A:0B code?

Start by visually inspecting the wiring and connectors for damage or corrosion. Then, test the assist step motor and control circuit for proper voltage and continuity.

6. How can I fix the B051A:0B code?

Repairs may include replacing a damaged assist step motor, repairing or replacing faulty wiring, cleaning corroded connectors, or reprogramming or replacing the control module.

7. How much does it cost to repair the B051A:0B code?

Repair costs vary depending on the issue but typically range from $100 to $500, depending on whether the motor, wiring, or control module needs replacement.

8. Can a blown fuse trigger the B051A:0B code?

While a blown fuse itself may not directly cause the code, it could be a symptom of an electrical short in the assist step motor circuit.

9. Does the B051A:0B code only affect certain vehicles?

This code is specific to vehicles equipped with motorized assist steps and may appear in brands or models that offer this feature, such as certain trucks or SUVs.

10. Will clearing the code fix the B051A:0B issue?

Clearing the code will temporarily remove it, but the underlying issue must be repaired to prevent the code from returning.