AutoCodes – GMC – B2151 GMC

B2151 GMC 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: B2151 GMC 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 614

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 B2151 GMC 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 B2151 GMC - Outside Rearview Mirror Position Sensor Input Voltage High - AutoCodes.com — B2151 GMC Code - Outside Rearview Mirror Position Sensor Input Voltage High

What does this mean?

What are the Possible Causes of the DTC B2151 GMC?

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 B2151 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 B2151 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 B2151 GMC Code

1. What are the common symptoms of OBDII code B2151 GMC (Outside Rearview Mirror Position Sensor Input Voltage High)?

- The common symptoms include malfunctioning power mirrors, erratic mirror movement, and possibly a warning light on the dashboard.

2. What are the possible causes of OBDII code B2151 GMC?

- The possible causes include a faulty outside rearview mirror position sensor, damaged wiring or connectors in the mirror system, or a problem with the mirror control module.

3. How can I diagnose the issue related to code B2151 GMC?

- You can diagnose the issue by conducting a visual inspection of the mirror system, checking for damaged wires or connectors, and using a scan tool to read the trouble codes and sensor data.

4. Can I still drive my vehicle with OBDII code B2151 GMC?

- It is generally safe to drive the vehicle with this code, but it is recommended to address the issue promptly to avoid any inconvenience or safety concerns related to malfunctioning mirrors.

5. Is it possible to reset OBDII code B2151 GMC without repairing the issue?

- Resetting the code without addressing the underlying problem will likely result in the code reappearing once the issue is detected again by the vehicle's system.

6. Are there any DIY repair tips for fixing OBDII code B2151 GMC?

- DIY repair tips may include checking and repairing any damaged wiring or connectors in the mirror system, and replacing the outside rearview mirror position sensor if necessary.

7. How much does it typically cost to repair OBDII code B2151 GMC at a mechanic or dealership?

- The cost of repairing this code can vary depending on the specific cause of the issue, but it may range from $100 to $300 for parts and labor.

8. Can extreme weather conditions affect the occurrence of OBDII code B2151 GMC?

- Extreme weather conditions, especially moisture and temperature fluctuations, can potentially impact the performance of the mirror system and contribute to the triggering of this code.

9. Will fixing OBDII code B2151 GMC improve my vehicle's overall performance?

- While fixing this specific code may not directly impact the overall performance of the vehicle, it will ensure proper functionality of the outside rearview mirror system for convenience and safety.

10. How long does it typically take to repair OBDII code B2151 GMC?

- The repair time for this code can vary based on the extent of the issue and the availability of parts, but it may take anywhere from half an hour to a few hours to complete the repair.