AutoCodes – GMC – B1277 GMC

B1277 GMC Code - Microphone 1 Input Signal Circuit

Quick Answer

For Cellular, Entertainment, and Navigation Systems: The Human Machine Interface Control Module uses the cellular telephone microphone for voice recognition and cellular features. Common causes include Faulty Cellular Phone Microphone (For Cellular, Entertainment, and Navigation Systems), Faulty Radio Volume Compensator Interior Noise Microphone (For Active Noise Cancellation System), Faulty Audio Amplifier (For Active Noise Cancellation System). 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 GMC indicates Microphone 1 Input Signal Circuit.
Common causes: Common causes include Faulty Cellular Phone Microphone (For Cellular, Entertainment, and Navigation Systems), Faulty Radio Volume Compensator Interior Noise Microphone (For Active Noise Cancellation System), Faulty Audio Amplifier (For Active Noise Cancellation System).
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 2,017

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 GMC Description

For Cellular, Entertainment, and Navigation Systems:
The Human Machine Interface Control Module uses the cellular telephone microphone for voice recognition and cellular features. The Human Machine Interface Control Module provides a bias voltage to each microphone (+) and (-) signal circuit for the operation of the microphone.
The radio provides the cellular phone microphone with a supplied voltage on the cellular phone microphone high signal circuit. When the microphone is in use, voice data from the user is sent back to the radio on the cellular microphone low signal circuit.

For Active Noise Cancellation System:
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.

OBDII Code B1277 GMC - Microphone 1 Input Signal Circuit - AutoCodes.com — B1277 GMC Code - Microphone 1 Input Signal Circuit

What does this mean?

What are the Possible Causes of the DTC B1277 GMC?

Faulty Cellular Phone Microphone (For Cellular, Entertainment, and Navigation Systems)
Faulty Radio Volume Compensator Interior Noise Microphone (For Active Noise Cancellation System)
Faulty Audio Amplifier (For Active Noise Cancellation System)
Faulty Human Machine Interface Control Module or Radio (For Cellular, Entertainment, and Navigation Systems)

How to Fix the DTC B1277 GMC?

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 GMC 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 B1277 GMC code?

Need more information on how to fix the B1277 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1277 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

B1277 2014 GMC Sierra — Microphone 1 Input Signal Circuit
B1277 2015 GMC Sierra — Microphone 1 Input Signal Circuit
B1277 2016 GMC Sierra — Microphone 1 Input Signal Circuit
B1277 2017 GMC Sierra — Microphone 1 Input Signal Circuit
B1277 2018 GMC Sierra — Microphone 1 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 B1277 GMC Code

1. What are the common symptoms of OBDII code B1277 GMC related to the Microphone 1 Input Signal Circuit?

- Common symptoms include issues with hands-free calling, voice command recognition, and overall functionality of the microphone system in the vehicle.

2. What are the possible causes of OBDII code B1277 GMC related to the Microphone 1 Input Signal Circuit?

- Possible causes may include a faulty microphone, damaged wiring or connectors, a malfunctioning audio control module, or software issues.

3. How can I diagnose the issue associated with OBDII code B1277 GMC for the Microphone 1 Input Signal Circuit?

- Diagnosis typically involves checking the microphone for physical damage, testing the wiring and connectors for continuity, and using diagnostic tools to scan the audio system for any faults.

4. Can I repair OBDII code B1277 GMC myself for the Microphone 1 Input Signal Circuit?

- Depending on your automotive repair skills, you may be able to address the issue by replacing the microphone, repairing damaged wiring, or resetting the audio control module. However, professional assistance may be needed for more complex repairs.

5. Is it safe to continue driving with OBDII code B1277 GMC related to the Microphone 1 Input Signal Circuit?

- While the code may not affect the drivability of the vehicle, it is important to address the underlying issue to ensure proper functioning of the microphone system and potentially avoid further audio system problems.

6. How much does it typically cost to repair OBDII code B1277 GMC for the Microphone 1 Input Signal Circuit?

- Repair costs can vary depending on the specific cause of the issue and whether you choose to address it yourself or seek professional help. Costs may range from a few dollars for simple fixes to a few hundred dollars for more complex repairs.

7. Are there any preventative measures to avoid OBDII code B1277 GMC related to the Microphone 1 Input Signal Circuit?

- Regularly checking and maintaining the microphone system, avoiding physical damage to the microphone or wiring, and following recommended maintenance schedules for the audio system can help prevent this code from occurring.

8. Can weather conditions affect OBDII code B1277 GMC for the Microphone 1 Input Signal Circuit?

- Extreme temperature changes, moisture, or humidity levels can potentially impact the performance of the microphone system and contribute to the occurrence of this OBDII code.