C0503

Symptoms

• ABS/ESP indicator is on
• Disabling the ABS system
• Incorrect operation of cruise control
• Errors in the operation of the stabilization system

Causes

• Left front wheel speed sensor malfunction
• Open or short circuit in wiring harness
• Damage to the sensor connector
• Problems with the ABS/ESP control unit
• Contamination or damage to the gear ring on the hub

How to Fix

1. Check the condition of the wheel speed sensor and its connector
2. Inspect the wiring harness for damage
3. Check sensor resistance (must meet specification)
4. Check the toothed ring on the hub for damage or contamination
5. If necessary, replace the sensor or repair the wiring harness
6. Clear error codes and check if C0503 returns

Related codes

Error C0503 by Vehicle Brand