AutoCodes – Generic – B2149

B2149 Code - Outside Rearview Mirror Position Sensor Input Voltage High

Quick Answer

The Memory Mirror Module (MMM) receives inputs from mirror position sensors during these functions: memory recall, memory seat and easy exit. Common causes include Faulty Outside Rearview Mirror Motor, Outside Rearview Mirror Motor harness is open or shorted, Outside Rearview Mirror Motor 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: B2149 indicates Outside Rearview Mirror Position Sensor Input Voltage High.
Common causes: Common causes include Faulty Outside Rearview Mirror Motor, Outside Rearview Mirror Motor harness is open or shorted, Outside Rearview Mirror Motor 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 3,638

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 B2149 Description

The Memory Mirror Module (MMM) receives inputs from mirror position sensors during these functions: memory recall, memory seat and easy exit. Potentiometers in position sensors vary in resistance as motors move outside rearview mirror. MMM receives a variable voltage input depending on resistance of the potentiometer. During memory set, MMM records voltage across mirrors. During memory recall, MMM moves mirror motors until the voltage across each potentiometer matches recorded the voltage. During normal operation, mirror position sensors are checked against out-of-range limits. Outside rearview mirrors horizontal and vertical position sensor input voltage is 4.75 volts or more.

OBDII Code B2149 - Outside Rearview Mirror Position Sensor Input Voltage High - AutoCodes.com — B2149 Code - Outside Rearview Mirror Position Sensor Input Voltage High

What does this mean?

What are the Possible Causes of the DTC B2149?

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

How to Fix the DTC B2149?

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 B2149 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.

Need more information about the B2149 code?

Need more information on how to fix the B2149 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B2149 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B2149 Buick — Outside Rearview Mirror Position Sensor Input Voltage High
B2149 Cadillac — Outside Rearview Mirror Position Sensor Input Voltage High
B2149 Chevrolet — Outside Rearview Mirror Position Sensor Input Voltage High
B2149 GMC — Outside Rearview Mirror Position Sensor Input Voltage High

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 B2149 Code

1. What does the OBDII code B2149 mean?

The B2149 code indicates that the input voltage from the outside rearview mirror position sensor is higher than the expected range.

2. What are the common symptoms of the B2149 code?

Symptoms may include unresponsive or erratic mirror adjustments, stored fault codes in the vehicleâ€™s system, and possibly a malfunction indicator light (MIL) on the dashboard.

3. What causes the B2149 code to appear?

Common causes include a faulty position sensor in the side mirror, damaged wiring, loose or corroded electrical connections, or a malfunction in the mirror control module.

4. How can I diagnose the B2149 code?

Use an OBDII scanner to confirm the code, inspect the mirror position sensor and wiring for visible damage, and check for proper voltage and continuity in the circuit.

5. Can I still drive with the B2149 code active?

Yes, you can usually drive with this code active, but the mirror adjustment function may not work properly, which could impact visibility and safety.

6. How do I fix the B2149 code?

Repairs may involve replacing the faulty mirror position sensor, repairing damaged wiring or connectors, or replacing the mirror control module if necessary.

7. Is the B2149 code specific to certain vehicle makes or models?

No, the B2149 code is a generic OBDII code, but its exact meaning and diagnostic steps may vary slightly depending on the vehicle's manufacturer.

8. How much does it cost to repair a B2149 code issue?

The cost can range from $50 to $300 or more, depending on whether the issue is a simple wiring fix or requires replacing the mirror position sensor or control module.

9. Can I clear the B2149 code without fixing the problem?

Clearing the code with an OBDII scanner may turn off the warning temporarily, but the issue will likely return if the underlying problem is not resolved.

10. What tools are needed to troubleshoot the B2149 code?

A multimeter, an OBDII scanner, and basic hand tools are typically needed to diagnose and repair this code effectively.