AutoCodes – GMC – B2143 GMC

B2143 GMC Code - Outside Rearview Mirror Reached Limit Of Travel

Quick Answer

Outside rearview mirror switch supplies inputs to Memory Mirror Module (MMM) to drive outside rearview mirrors horizontal and vertical motors. Common causes include Faulty Outside Rearview Mirror Switch, Outside Rearview Mirror Switch harness is open or shorted, Outside Rearview Mirror Switch 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: B2143 GMC indicates Outside Rearview Mirror Reached Limit Of Travel.
Common causes: Common causes include Faulty Outside Rearview Mirror Switch, Outside Rearview Mirror Switch harness is open or shorted, Outside Rearview Mirror Switch 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 630

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 Sep 19, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B2143 GMC Description

Outside rearview mirror switch supplies inputs to Memory Mirror Module (MMM) to drive outside rearview mirrors horizontal and vertical motors. Outside rearview mirror switch must be in either L or R position in order to operate outside rearview mirror. When outside rearview mirror switch is actuated, the battery voltage input signal and the ground input signal is sent to MMM. When MMM recognizes input combination, it moves the appropriate mirror to the requested direction. If MMM does not recognize input combination as a valid input, it ignores combination and does not move outside rearview mirror.

OBDII Code B2143 GMC - Outside Rearview Mirror Reached Limit Of Travel - AutoCodes.com — B2143 GMC Code - Outside Rearview Mirror Reached Limit Of Travel

What does this mean?

What are the Possible Causes of the DTC B2143 GMC?

Faulty Outside Rearview Mirror Switch
Outside Rearview Mirror Switch harness is open or shorted
Outside Rearview Mirror Switch circuit poor electrical connection
Faulty Memory Mirror Module (MMM)

How to Fix the DTC B2143 GMC?

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 B2143 GMC 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 B2143 GMC Code

1. What does the OBDII code B2143 mean on a GMC vehicle?

B2143 indicates that the outside rearview mirror has reached its limit of travel, meaning the mirror's adjustment mechanism has moved to its maximum allowable position.

2. What are the common symptoms of the B2143 code?

Symptoms may include the inability to adjust the side mirror further in one or more directions, unexpected stopping during mirror adjustment, or a stored warning code.

3. What causes the B2143 code to appear?

The code can be caused by a malfunctioning mirror motor, a stuck or obstructed mirror, an electrical issue such as a damaged wiring harness, or a software glitch in the control module.

4. Can I still drive my GMC vehicle with the B2143 code?

Yes, the code does not affect drivability, but it may limit the functionality of the side mirror, which could reduce visibility and safety when driving.

5. How can I diagnose the B2143 code?

Start by inspecting the mirror for physical obstructions, check the wiring and connectors for damage, and use a scan tool to confirm the code and test the mirror adjustment mechanism.

6. Can the B2143 code be fixed without replacing any parts?

In some cases, clearing debris or recalibrating the mirror through the vehicle's settings might resolve the issue without replacing parts.

7. How much does it cost to repair a B2143 code on a GMC vehicle?

The cost varies depending on the issue, ranging from $50 for simple fixes like cleaning or recalibrating to $200-$400 if the mirror motor or control module needs replacement.

8. Can a software update fix the B2143 code?

If the issue is related to a software glitch in the control module, a firmware update from the dealership may resolve the problem.

9. What tools are needed to fix the B2143 code?

A basic OBDII scan tool, multimeter, and potentially a screwdriver or trim removal tool for accessing the mirror assembly may be required for diagnosis and repair.

10. Should I take my vehicle to a professional to fix the B2143 code?

If you are not comfortable diagnosing electrical systems or disassembling the mirror, it is recommended to consult a certified mechanic or dealership for repair.