OBD Guide

C0504

Left Front Wheel Speed Sensor A Intermittent/Erratic

C0504 is an OBD-II diagnostic trouble code meaning: Left Front Wheel Speed Sensor A Intermittent/Erratic. Common causes: damage to the wheel speed sensor, contamination of the sensor or its magnetic ring. Estimated repair cost: $56–167.

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

Symptoms

  • Incorrect ABS operation
  • Check engine light comes on
  • Loss of ESP or TCS function
  • Unstable speedometer readings

Causes

  • Damage to the wheel speed sensor
  • Contamination of the sensor or its magnetic ring
  • Damage to the sensor wiring harness
  • Poor contact in the sensor connector
  • ECU malfunction

How to Fix

  1. Check the status of the wheel speed sensor
  2. Clean the sensor and magnetic ring
  3. Check wiring harness and connectors for damage
  4. Replace the wheel speed sensor if necessary
  5. Check the operation of the ABS/ESP systems after repair

Related codes

Error C0504 by Vehicle Brand

FAQ

What does the C0504 code mean?

C0504 is an OBD-II diagnostic trouble code that indicates: Left Front Wheel Speed Sensor A Intermittent/Erratic

What causes a C0504 error code?

The most common causes of C0504 include: Damage to the wheel speed sensor; Contamination of the sensor or its magnetic ring; Damage to the sensor wiring harness; Poor contact in the sensor connector.

How do I fix a C0504 diagnostic trouble code?

To fix C0504: Check the status of the wheel speed sensor. Clean the sensor and magnetic ring. Check wiring harness and connectors for damage. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C0504?

Limited driving only, diagnose soon

How much does it cost to fix C0504?

The estimated repair cost for C0504 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

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