Fault code C1101 – a step-by-step guide to diagnosing and fixing it

Error code C1101 is displayed and the check engine light is on - what does this mean?

The DTC C1101 is recognized by the OBD/EOBD system and indicates a fault in the ABS system, more specifically a defect in the wheel speed sensor or its circuit. This fault code mainly affects the anti-lock braking system and may have slight variations in the description depending on the vehicle manufacturer.

What causes can this fault code have?

• Defective wheel speed sensor
• Damaged sensor cable or cable break
• Corroded or loose plug connections
• Dirty or damaged sensor ring on the wheel
• Defective ABS control unit
• Interruption in the power supply to the sensor
• Mechanical damage to the sensor bracket
• Incorrect installation or air gap between sensor and sensor ring

What symptoms occur in parallel with fault code C1101?

• ABS warning light: The ABS indicator light in the dashboard lights up continuously
• Malfunction: The anti-lock braking system no longer functions properly
• ESP malfunction: The electronic stability program may also be impaired
• Braking behavior: Extended braking distances during emergency braking on slippery surfaces
• Traction control: The traction control can also fail
• Lack of vehicle stability: There is no electronic support in critical driving situations

How to fix the problem of trouble code C1101?

• Repairing trouble code C1101 requires a systematic approach to identify the exact source of the fault.
• Replace the wheel speed sensor: Remove the defective sensor and replace it with a new original part, making sure the air gap is correct
• Carry out cable repair: Locate damaged cables, repair severed areas or replace complete wiring harness
• Clean plug connections: Clean all plug connections of the ABS system, remove corrosion and treat with contact spray
• Repair the sensor ring: Clean dirty or damaged sensor ring on the wheel or replace if irreparably damaged
• Replace ABS control unit: If the control unit is defective, repair in a specialist workshop or replace with a functional unit
• Complete system diagnosis: Professional diagnosis of all ABS components with appropriate test technology and subsequent calibration