AutoCodes – Generic – B051A:01

B051A:01 Code - Left Side Assist Step Motor Control Circuit Short to Battery

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:01 indicates Left Side Assist Step Motor Control Circuit Short to Battery.
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 168

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:01 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 a motor control circuit is shorted to battery voltage.

OBDII Code B051A:01 - Left Side Assist Step Motor Control Circuit Short to Battery - AutoCodes.com — B051A:01 Code - Left Side Assist Step Motor Control Circuit Short to Battery

What does this mean?

What are the Possible Causes of the DTC B051A:01?

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:01?

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:01 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:01 Code

1. What does the OBDII code B051A:01 mean?

The code B051A:01 indicates a short to battery in the control circuit of the left side assist step motor.

2. What are the common symptoms of the B051A:01 code?

Symptoms may include the left side assist step not deploying or retracting, or it being stuck in one position.

3. What causes the B051A:01 code?

Common causes include damaged wiring, a short circuit in the control circuit, a faulty left side assist step motor, or issues with the control module.

4. Can I still drive my vehicle with the B051A:01 code?

Yes, the vehicle can still be driven, but the left side assist step may not function properly, potentially causing inconvenience.

5. How can I diagnose the B051A:01 code?

Inspect the wiring and connectors for damage or corrosion, check the assist step motor for faults, and test the control circuit for continuity and shorts.

6. How do I fix the B051A:01 code?

Repair or replace damaged wiring, connectors, or the assist step motor. If necessary, replace the control module.

7. Is the B051A:01 code specific to certain vehicles?

Yes, this code is typically found on vehicles equipped with power assist steps, such as certain trucks or SUVs.

8. How much does it cost to repair the B051A:01 code?

Costs vary depending on the extent of damage, but repairing wiring may cost $100-$300, while replacing the assist step motor could cost $500-$800.

9. Can I reset the B051A:01 code without making repairs?

Clearing the code without addressing the issue may temporarily remove the warning, but the problem will likely return.

10. How do I prevent the B051A:01 code from occurring again?

Regularly inspect the assist step components for wear, clean connectors to prevent corrosion, and address electrical issues promptly.

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