AutoCodes – Cadillac – B1277 Cadillac

B1277 Cadillac 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 Cadillac 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 1,196

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

What does this mean?

What are the Possible Causes of the DTC B1277 Cadillac?

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 Cadillac?

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 Cadillac 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 Cadillac Code

1. What are the common symptoms of OBDII code B1277 Cadillac?

The common symptoms of OBDII code B1277 Cadillac include a malfunctioning microphone, poor sound quality during calls, and issues with voice recognition systems.

2. What causes the OBDII code B1277 Cadillac to trigger?

The OBDII code B1277 Cadillac is triggered when there is a fault in the Microphone 1 input signal circuit, which may be caused by a defective microphone, wiring issues, or a faulty control module.

3. How can I diagnose the Microphone 1 input signal circuit issue?

Diagnosing the Microphone 1 input signal circuit issue involves checking the microphone for physical damage, inspecting the wiring for any breaks or shorts, and using a multimeter to test for continuity and proper voltage.

4. Can I repair the Microphone 1 input signal circuit issue myself?

Repairing the Microphone 1 input signal circuit issue yourself is possible if you have the necessary tools and expertise. It may involve replacing the microphone, repairing or replacing damaged wiring, or reprogramming the control module.

5. Is it safe to continue driving with the OBDII code B1277 Cadillac triggered?

It is generally safe to continue driving with the OBDII code B1277 Cadillac triggered, as it mainly affects the microphone and voice recognition system. However, it is recommended to address the issue promptly to ensure proper functionality.

6. How much does it typically cost to repair the Microphone 1 input signal circuit issue?

The cost of repairing the Microphone 1 input signal circuit issue can vary depending on the extent of the damage and the specific components that need to be replaced. It may range from a few hundred to a thousand dollars.

7. Can a faulty Microphone 1 input signal circuit affect other vehicle systems?

A faulty Microphone 1 input signal circuit is unlikely to affect other vehicle systems directly but may impact the functionality of the audio and communication systems in the vehicle.

8. Are there any common pitfalls to avoid when repairing the Microphone 1 input signal circuit?

Common pitfalls to avoid when repairing the Microphone 1 input signal circuit include misdiagnosing the issue, using incorrect replacement parts, and not properly securing the wiring connections during repair.

9. How long does it typically take to repair the Microphone 1 input signal circuit issue?

The repair time for the Microphone 1 input signal circuit issue can vary depending on the complexity of the problem and the accessibility of the components. It may take anywhere from a couple of hours to a full day.

10. Will resetting the OBDII code B1277 Cadillac clear the issue permanently?

Resetting the OBDII code B1277 Cadillac may temporarily clear the issue, but if the underlying problem with the Microphone 1 input signal circuit is not addressed, the code is likely to reappear. It is recommended to diagnose and repair the root cause of the issue for a permanent solution.