OBD Guide
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B1277

Microphone 1 Input Signal Circuit

B1277 is an OBD-II diagnostic trouble code meaning: Microphone 1 Input Signal Circuit. Common causes: open or short circuit in microphone wiring harness, poor contact in the microphone jack. Estimated repair cost: $33–167.

Severity
✅ Low
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$33–167 (est.)

Symptoms

  • Lack of response to voice commands
  • Problems with quality of hands-free calls
  • Voice control system error message
  • Incorrect operation of the active noise cancellation system (if equipped)

Causes

  • Open or short circuit in microphone wiring harness
  • Poor contact in the microphone jack
  • Faulty microphone
  • Problems with the signal processing module
  • Mechanical damage to the microphone or wires
  • Contact corrosion

How to Fix

  1. Visually inspect the microphone and wiring harness for damage
  2. Check the integrity and quality of the contacts in the microphone connector
  3. Measure the resistance and voltage on the microphone circuit according to the repair manual
  4. Check the presence of a signal from the microphone with an oscilloscope
  5. Replace the microphone if a malfunction is detected
  6. If necessary, replace damaged wires or connectors
  7. Clear error codes and check if B1277 returns

Related codes

B1278B1279U0155

FAQ

What does the B1277 code mean?

B1277 is an OBD-II diagnostic trouble code that indicates: Microphone 1 Input Signal Circuit

What causes a B1277 error code?

The most common causes of B1277 include: Open or short circuit in microphone wiring harness; Poor contact in the microphone jack; Faulty microphone; Problems with the signal processing module.

How do I fix a B1277 diagnostic trouble code?

To fix B1277: Visually inspect the microphone and wiring harness for damage. Check the integrity and quality of the contacts in the microphone connector. Measure the resistance and voltage on the microphone circuit according to the repair manual. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1277?

Yes, but get it checked soon

How much does it cost to fix B1277?

The estimated repair cost for B1277 is $33–167. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat