AutoCodes.com | All About OBDII Engine Codes
AutoCodes - Generic - B127D

B127D Code - Microphone 3 Input Signal Circuit

- Code Popularity: 1,996 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
Table of contents
Share on Facebook   Share on Twitter   Share on Linkedin

What are the Possible Causes of the DTC B127D?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • 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
⚠ Does your Car have Safety Recalls? → Check here

How to Fix the DTC B127D?

Review the 'Possible Causes' mentioned above and visually examine the corresponding wiring harness and connectors. Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.

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.

Search for B127D Questions and Answers: Search here →

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B127D code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

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

Need More Information on the Code?

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

Information for Specific Makes

Need Help with the Code?

Get the B127D code diagnosed by a professional: Find a repair shop in your area

Code B127D comments

Help us improve AutoCodes.com. Leave a comment below or tell us if the information above helps you fix the code. What are the symptoms on your vehicle for the B127D code? Have you replaced any parts?
Any information is appreciated. Thanks