OBD Guide
ENFRDEESPT

C129D

Brake Pedal Position Sensor 4 Circuit Low Input

C129D is an OBD-II diagnostic trouble code meaning: Brake Pedal Position Sensor 4 Circuit Low Input. Common causes: open or short circuit in the sensor circuit, malfunction of the brake pedal position sensor. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • ABS or ESP indicator is on
  • Unstable operation of the brake system
  • Problems activating the ESP system

Causes

  • Open or short circuit in the sensor circuit
  • Malfunction of the brake pedal position sensor
  • Poor contact in the sensor connector
  • Wiring Harness Problems
  • Malfunction of the brake system control unit

How to Fix

  1. Check the integrity of the sensor circuit
  2. Inspect connectors and contacts for oxidation or damage
  3. Check the resistance of the brake pedal position sensor
  4. Replace sensor if necessary
  5. Check and reflash the brake system control unit

Related codes

C129CC129EC129F

FAQ

What does the C129D code mean?

C129D is an OBD-II diagnostic trouble code that indicates: Brake Pedal Position Sensor 4 Circuit Low Input

What causes a C129D error code?

The most common causes of C129D include: Open or short circuit in the sensor circuit; Malfunction of the brake pedal position sensor; Poor contact in the sensor connector; Wiring Harness Problems.

How do I fix a C129D diagnostic trouble code?

To fix C129D: Check the integrity of the sensor circuit. Inspect connectors and contacts for oxidation or damage. Check the resistance of the brake pedal position sensor. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C129D?

Limited driving only, diagnose soon

How much does it cost to fix C129D?

The estimated repair cost for C129D is $56–167. Actual cost depends on your vehicle, location, and labor rates.

FRDEESPT

See also: Russian version · NationStat