Engine-Codes - Chevrolet - B127D Chevrolet

B127D Chevrolet Code - Microphone 3 Input Signal Circuit

- Code Popularity: 698 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
Table of contents

What are the Possible Causes of the Code 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 B127D Chevrolet Code?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

Code B127D Chevrolet 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 B127D Chevrolet?

Labor: 1.0

The cost to diagnose the B127D Chevrolet code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.

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What are Code B127D Chevrolet Possible Symptoms?

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

What Does the B127D Chevrolet Code Mean?

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.

B127D Chevrolet Code - Microphone 3 Input Signal Circuit

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