AutoCodes – Chevrolet – B127C Chevrolet

B127C Chevrolet Code - Microphone 2 Input Signal Circuit

Quick Answer

The active noise cancellation system uses three microphones in the vehicle headliner: one above each front seating position, and one above the rear seat. Common causes include Faulty Radio Volume Compensator Interior Noise Microphone, Radio Volume Compensator Interior Noise Microphone harness is open or shorted, Radio Volume Compensator Interior Noise Microphone 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: B127C Chevrolet indicates Microphone 2 Input Signal Circuit.
Common causes: Common causes include Faulty Radio Volume Compensator Interior Noise Microphone, Radio Volume Compensator Interior Noise Microphone harness is open or shorted, Radio Volume Compensator Interior Noise Microphone 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 1,720

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 29, 2024

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code B127C Chevrolet Description

The active noise cancellation system uses three microphones in the vehicle headliner: one above each front seating position, and one above the rear seat. The Audio Amplifier provides a bias voltage to each microphone (+) and (-) signal circuit for the operation of the microphone. The microphones monitor the vehicle cabin for undesirable engine sounds. The Audio Amplifier uses the microphone inputs and an engine RPM signal to determine the frequency of the undesirable sound. The Diagnostic Trouble Code (DTC) will be set when a fault is detected on the specified (+) or (−) signal circuit for more than 1.5 seconds.

OBDII Code B127C Chevrolet - Microphone 2 Input Signal Circuit - AutoCodes.com — B127C Chevrolet Code - Microphone 2 Input Signal Circuit

What does this mean?

What are the Possible Causes of the DTC B127C Chevrolet?

Faulty Radio Volume Compensator Interior Noise Microphone
Radio Volume Compensator Interior Noise Microphone harness is open or shorted
Radio Volume Compensator Interior Noise Microphone circuit poor electrical connection
Faulty Audio Amplifier

How to Fix the DTC B127C Chevrolet?

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

Installation of aftermarket replacement speakers, additional speakers/subwoofers, or aftermarket exhaust systems can cause undesirable behavior of the active noise cancellation system. The noise reduction microphones have foam blocks above them to seal the microphones and aid in the reduction of headliner vibration. Missing or out of place foam blocks can impact system performance.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B127C Chevrolet 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 B127C Chevrolet code?

Need more information on how to fix the B127C Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

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Information for Specific Chevrolet Models

B127C 2014 Chevrolet Silverado — Microphone 2 Input Signal Circuit
B127C 2015 Chevrolet Silverado — Microphone 2 Input Signal Circuit
B127C 2016 Chevrolet Silverado — Microphone 2 Input Signal Circuit
B127C 2017 Chevrolet Silverado — Microphone 2 Input Signal Circuit
B127C 2018 Chevrolet Silverado — Microphone 2 Input Signal Circuit

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 B127C Chevrolet Code

1. What are the common symptoms of OBDII code B127C Chevrolet related to the Microphone 2 Input Signal Circuit?

- Common symptoms include issues with hands-free calling, voice commands not working, or poor sound quality during phone calls.

2. What are some possible causes of OBDII code B127C Chevrolet for the Microphone 2 Input Signal Circuit?

- Potential causes include a faulty microphone, damaged wiring, loose connections, or a malfunctioning audio control module.

3. How can I diagnose the issue causing OBDII code B127C Chevrolet for the Microphone 2 Input Signal Circuit?

- Diagnose by checking the microphone for physical damage, inspecting wiring for breaks or loose connections, and testing the audio control module for proper functionality.

4. Is it safe to continue driving with OBDII code B127C Chevrolet related to the Microphone 2 Input Signal Circuit?

- It is generally safe to drive with this code, but it is advisable to address the issue to restore proper functionality and convenience features.

5. Can I repair OBDII code B127C Chevrolet for the Microphone 2 Input Signal Circuit myself?

- Depending on your skill level, you may be able to repair this issue by replacing the microphone, repairing wiring, or addressing loose connections. Professional help may be required for more complex repairs.

6. Are there any simple troubleshooting steps I can take for OBDII code B127C Chevrolet involving the Microphone 2 Input Signal Circuit?

- You can start by checking for any visible damage to the microphone or wiring, ensuring all connections are secure, and resetting the audio system to see if the issue resolves.

7. Will fixing OBDII code B127C Chevrolet for the Microphone 2 Input Signal Circuit improve my vehicle's overall performance?

- Fixing this code will primarily restore functionality to hands-free calling and voice commands, enhancing convenience and safety features rather than affecting overall performance.

8. How much can I expect to pay to repair OBDII code B127C Chevrolet related to the Microphone 2 Input Signal Circuit?

- Repair costs can vary depending on the exact cause of the issue, but they may range from a few hundred to over a thousand dollars, including parts and labor.

9. Are there any recalls or technical service bulletins related to OBDII code B127C Chevrolet for the Microphone 2 Input Signal Circuit?

- It is recommended to check with Chevrolet dealerships or online resources for any relevant recalls or technical service bulletins addressing this specific OBDII code and issue.

10. Can OBDII code B127C Chevrolet for the Microphone 2 Input Signal Circuit cause other problems in my vehicle?

- While this code mainly affects the functionality of the microphone and audio system, unresolved issues could potentially impact other vehicle systems that rely on proper audio input signals.