B1277 2018 GMC Sierra 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 2018 GMC Sierra 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.
Code B1277 2018 GMC Sierra Description
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.
What are the Possible Causes of the DTC B1277 2018 GMC Sierra?
- 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 2018 GMC Sierra?
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.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the B1277 2018 GMC Sierra 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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Frequently Asked Questions about B1277 2018 GMC Sierra Code
1. What does OBDII code B1277 mean on a 2018 GMC Sierra?
Code B1277 indicates an issue with the Microphone 1 input signal circuit, which is part of the vehicle's infotainment or telematics system.
2. What are the common symptoms of code B1277?
Symptoms may include poor or no voice recognition, issues with hands-free calling, or a malfunctioning infotainment microphone.
3. What causes the B1277 code to appear?
Common causes include a faulty microphone, damaged wiring or connectors in the microphone circuit, or a failure in the infotainment control module.
4. How can I diagnose the B1277 code?
Start by inspecting the microphone and its wiring for damage or loose connections. Use a scan tool to check for related codes and verify system functionality.
5. Can a bad microphone trigger code B1277?
Yes, a defective microphone can cause the B1277 code as it may fail to send proper signals to the infotainment system.
6. Is the B1277 code critical to address immediately?
While it doesn't usually affect vehicle operation, it should be addressed promptly to restore hands-free functionality and ensure proper system operation.
7. How do I fix the B1277 code?
Repair or replace damaged wiring, connectors, or the microphone itself. If the issue persists, the infotainment control module may need to be checked or reprogrammed.
8. Can I clear the B1277 code without repairs?
Clearing the code without addressing the cause will likely result in the code returning. Proper diagnosis and repair are recommended.
9. Can software updates fix the B1277 code on a 2018 GMC Sierra?
In some cases, a software update for the infotainment system may resolve the issue if it’s related to a programming error.
10. How much does it cost to repair code B1277?
The cost depends on the exact issue. Replacing a microphone typically costs $50-$150, while wiring repairs or module replacements can vary widely.
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