AutoCodes – Generic – B1277:01

B1277:01 Code - Microphone 1 Input Signal Circuit Short to Voltage

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: B1277:01 indicates Microphone 1 Input Signal Circuit Short to Voltage.
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 215

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 B1277:01 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 short to voltage is detected on the specified (+) or (−) signal circuit for more than 1.5 seconds

OBDII Code B1277:01 - Microphone 1 Input Signal Circuit Short to Voltage - AutoCodes.com — B1277:01 Code - Microphone 1 Input Signal Circuit Short to Voltage

What does this mean?

What are the Possible Causes of the DTC B1277:01?

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 B1277:01?

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 B1277:01 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 B1277:01 Code

1. What are common symptoms of OBDII code B1277:01?

- Common symptoms include a malfunctioning microphone, distorted or no sound from the microphone, and issues with hands-free calling features in the vehicle.

2. What can cause the Microphone 1 Input Signal Circuit to short to voltage?

- Possible causes include a short circuit in the wiring, a faulty microphone, water damage to the microphone or wiring, or a malfunction in the audio system.

3. How can I diagnose the Microphone 1 Input Signal Circuit short to voltage issue?

- Diagnose the problem by checking the wiring for any visible damage, testing the microphone for functionality, inspecting for water damage, and using an OBDII scanner to read and clear the code.

4. Can I repair the Microphone 1 Input Signal Circuit issue myself?

- Depending on your expertise, you may be able to repair the issue yourself by replacing the microphone, repairing the wiring, or addressing any other identified causes of the short to voltage condition.

5. Is it safe to continue driving with OBDII code B1277:01?

- While the code may not affect the drivability of the vehicle, it is recommended to address the issue promptly to ensure the proper functioning of hands-free communication features and avoid potential safety hazards.

6. How much does it typically cost to repair the Microphone 1 Input Signal Circuit issue?

- Repair costs can vary depending on the underlying cause and whether you choose to perform the repairs yourself or take your vehicle to a mechanic. Costs may include parts and labor.

7. Will disconnecting the microphone resolve the B1277:01 code?

- Disconnecting the microphone may temporarily clear the code, but it is not a recommended long-term solution as it will disable hands-free calling features and affect the overall audio system functionality.

8. Can extreme temperatures or humidity contribute to the Microphone 1 Input Signal Circuit short to voltage problem?

- Yes, extreme temperatures or humidity can potentially damage the microphone or wiring, leading to a short to voltage condition. It is important to keep the vehicle's interior environment stable to prevent such issues.

9. How long does it take to repair the Microphone 1 Input Signal Circuit issue?

- The repair time can vary based on the complexity of the problem and the availability of parts. Simple fixes like replacing the microphone may take less time, while more extensive wiring repairs could take longer.

10. Will resetting the vehicle's audio system clear the B1277:01 code?

- Resetting the audio system may temporarily clear the code, but if the underlying issue causing the short to voltage condition is not addressed, the code is likely to reappear. It's important to diagnose and fix the root cause of the problem.