OBD Guide

U129C

F-CAN Malfunction EPS Control Unit and Driving Support System Control Unit

U129C is an OBD-II diagnostic trouble code meaning: F-CAN Malfunction EPS Control Unit and Driving Support System Control Unit. Common causes: broken or damaged can bus wires, corrosion of connectors. Estimated repair cost: $6–167.

Severity
🔴 High
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$6–167 (est.)

Symptoms

  • Check Engine Light Is On
  • Disabling driver assistance systems
  • Power steering problems
  • Unstable operation of cruise control
  • Errors in other CAN bus-related systems

Causes

  • Broken or damaged CAN bus wires
  • Corrosion of connectors
  • EPS control unit malfunction
  • Problems with the driving assistance systems control unit
  • Poor ground contact

How to Fix

  1. Check the integrity of the CAN bus wiring
  2. Inspect connectors for corrosion
  3. Check power and ground of modules
  4. Scan all modules for additional errors
  5. If necessary, replace the faulty module

Related codes

FAQ

What does the U129C code mean?

U129C is an OBD-II diagnostic trouble code that indicates: F-CAN Malfunction EPS Control Unit and Driving Support System Control Unit

What causes a U129C error code?

The most common causes of U129C include: Broken or damaged CAN bus wires; Corrosion of connectors; EPS control unit malfunction; Problems with the driving assistance systems control unit.

How do I fix a U129C diagnostic trouble code?

To fix U129C: Check the integrity of the CAN bus wiring. Inspect connectors for corrosion. Check power and ground of modules. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U129C?

Yes, but get it checked soon

How much does it cost to fix U129C?

The estimated repair cost for U129C is $6–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat