AutoCodes – Chevrolet – B127D Chevrolet

B127D Chevrolet Code - Microphone 3 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: B127D Chevrolet indicates Microphone 3 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 1,119

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 B127D 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 B127D Chevrolet - Microphone 3 Input Signal Circuit - AutoCodes.com — B127D Chevrolet Code - Microphone 3 Input Signal Circuit

What does this mean?

What are the Possible Causes of the DTC B127D 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 B127D 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 B127D 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 B127D Chevrolet code?

Need more information on how to fix the B127D Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

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Information for Specific Chevrolet Models

B127D 2014 Chevrolet Silverado — Microphone 3 Input Signal Circuit
B127D 2015 Chevrolet Silverado — Microphone 3 Input Signal Circuit
B127D 2016 Chevrolet Silverado — Microphone 3 Input Signal Circuit
B127D 2017 Chevrolet Silverado — Microphone 3 Input Signal Circuit
B127D 2018 Chevrolet Silverado — Microphone 3 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 B127D Chevrolet Code

1. What are the common symptoms of OBDII code B127D (Chevrolet) related to the Microphone 3 Input Signal Circuit?

The common symptoms include malfunctioning hands-free calling, voice command system issues, and poor quality or loss of sound from the vehicle's microphone.

2. What are the possible causes of the OBDII code B127D (Chevrolet) indicating Microphone 3 Input Signal Circuit problems?

Possible causes include a faulty microphone, wiring issues, a defective audio control module, or a malfunction in the vehicle's communication network.

3. How can I diagnose the Microphone 3 Input Signal Circuit issue related to code B127D in my Chevrolet?

Diagnose by checking the microphone for physical damage, inspecting the wiring for any breaks or shorts, testing the audio control module, and using a diagnostic scanner to analyze the communication network.

4. What are some repair tips for fixing the Microphone 3 Input Signal Circuit problem causing code B127D in a Chevrolet?

Repair tips include replacing the faulty microphone, repairing or replacing damaged wiring, addressing issues with the audio control module, and ensuring proper communication network connections.

5. Can I fix the OBDII code B127D (Chevrolet) Microphone 3 Input Signal Circuit issue myself?

While some basic checks and repairs can be done by DIY enthusiasts, diagnosing and repairing complex issues related to the Microphone 3 Input Signal Circuit may require professional expertise and specialized tools.

6. Is it safe to continue driving my Chevrolet with the OBDII code B127D indicating a problem with the Microphone 3 Input Signal Circuit?

It is generally safe to drive the vehicle with this code, but it is recommended to address the issue promptly to ensure proper functioning of the hands-free calling and voice command systems.

7. How much does it typically cost to repair the Microphone 3 Input Signal Circuit problem associated with OBDII code B127D in a Chevrolet?

The cost of repair can vary depending on the exact cause of the issue, but it may range from around $100 for basic fixes to several hundred dollars for more complex repairs involving module replacement.

8. Will resetting the OBDII code B127D related to the Microphone 3 Input Signal Circuit temporarily resolve the issue?

Resetting the code may temporarily clear the warning light, but the underlying problem with the Microphone 3 Input Signal Circuit will persist unless properly diagnosed and repaired.

9. Can extreme weather conditions or rough driving cause the Microphone 3 Input Signal Circuit problem triggering OBDII code B127D in a Chevrolet?

Extreme weather conditions or rough driving can potentially contribute to wiring damage or component failure, which may lead to issues with the Microphone 3 Input Signal Circuit.

10. How long does it usually take to repair the Microphone 3 Input Signal Circuit issue indicated by OBDII code B127D in a Chevrolet?

The repair time can vary based on the exact cause of the problem and the complexity of the fix, but it may take anywhere from a few hours to a full day to address the Microphone 3 Input Signal Circuit issue thoroughly.