OBD Guide

U1129

Lost Communications With Audio Amplifier

U1129 is an OBD-II diagnostic trouble code meaning: Lost Communications With Audio Amplifier. Common causes: broken or damaged can bus wires to the audio amplifier, malfunction of the audio amplifier itself. Estimated repair cost: ~$278.

Severity
Low
Can you drive?
Yes, but get it checked soon
Approx. repair cost
~$278 (est.)

Symptoms

  • Complete absence of sound from the audio system
  • Error information message on display
  • The audio system does not work correctly (sound interruptions)
  • Lack of communication with the amplifier during diagnostics

Causes

  • Broken or damaged CAN bus wires to the audio amplifier
  • Malfunction of the audio amplifier itself
  • Audio amplifier power or grounding problems
  • Corrosion or poor contact in connectors
  • Software failure in the head unit or amplifier

How to Fix

  1. Conduct diagnostics of the CAN bus for breaks and short circuits
  2. Check the power and ground at the audio amplifier connector
  3. Inspect and clean the contacts of the amplifier and head unit connectors
  4. Perform flashing (software update) of the head unit and amplifier (if available)
  5. Replace a faulty audio amplifier

Related codes

FAQ

What does the U1129 code mean?

U1129 is an OBD-II diagnostic trouble code that indicates: Lost Communications With Audio Amplifier

What causes a U1129 error code?

The most common causes of U1129 include: Broken or damaged CAN bus wires to the audio amplifier; Malfunction of the audio amplifier itself; Audio amplifier power or grounding problems; Corrosion or poor contact in connectors.

How do I fix a U1129 diagnostic trouble code?

To fix U1129: Conduct diagnostics of the CAN bus for breaks and short circuits. Check the power and ground at the audio amplifier connector. Inspect and clean the contacts of the amplifier and head unit connectors. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U1129?

Yes, but get it checked soon

How much does it cost to fix U1129?

The estimated repair cost for U1129 is ~$278. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat