AutoCodes – Buick – B2140 Buick

B2140 Buick 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: B2140 Buick 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 508

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 B2140 Buick 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 B2140 Buick - Outside Rearview Mirror Reached Limit Of Travel - AutoCodes.com — B2140 Buick Code - Outside Rearview Mirror Reached Limit Of Travel

What does this mean?

What are the Possible Causes of the DTC B2140 Buick?

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 B2140 Buick?

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 B2140 Buick 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 B2140 Buick Code

1. What does the OBDII code B2140 mean on a Buick?

B2140 indicates that the outside rearview mirror has reached its limit of travel, meaning the mirror cannot adjust further in one or more directions.

2. What are the common symptoms of the B2140 code on a Buick?

Symptoms include limited or no movement of the outside rearview mirror, unusual clicking noises when adjusting the mirror, or the mirror being stuck in one position.

3. What causes the B2140 code to appear?

The code is typically caused by a malfunction in the mirror adjustment motor, a mechanical obstruction, damaged wiring, or a faulty mirror control module.

4. Can I still drive my Buick with the B2140 code active?

Yes, you can drive the vehicle, but the inability to adjust the mirror properly may affect visibility and safety while driving.

5. How can I diagnose the B2140 code on my Buick?

Start by inspecting the mirror for physical obstructions or damage, check the wiring and connectors for corrosion or breaks, and use a diagnostic scanner to confirm the code and test the mirror motor.

6. What is the most common fix for the B2140 code?

The most common fix is replacing the faulty mirror adjustment motor or addressing wiring issues that prevent proper function.

7. How much does it cost to repair the B2140 code on a Buick?

Repair costs can range from $100 to $300, depending on whether the issue is a faulty motor, wiring repair, or module replacement.

8. Can a blown fuse cause the B2140 code on a Buick?

While uncommon, a blown fuse related to the mirror adjustment system can interfere with its operation and trigger the code. Checking the fuse box is a good starting point.

9. Will clearing the B2140 code with a scanner fix the problem?

Clearing the code will reset the warning temporarily, but if the underlying issue isnâ€™t resolved, the code will likely return.

10. Can I fix the B2140 code on my Buick myself?

If you have basic mechanical skills, you may be able to fix simple issues like removing obstructions or repairing wiring. For motor or module replacement, professional assistance is recommended.