Fault code C1233 – a step-by-step guide to diagnosing and fixing it

Error code C1233 is displayed and the check engine light is on - what does this mean?

The DTC C1233 is recognized by the OBD/EOBD system and indicates a problem with the ABS system, specifically with the wheel speed sensor or its circuit. This trouble code relates to the anti-lock braking system and can vary slightly depending on the vehicle manufacturer, but basically refers to malfunctions in the wheel speed measurement.

What causes can this fault code have?

• Defective wheel speed sensor
• Damaged or corroded sensor cable
• Loose or corroded plug connections
• Dirty or damaged sensor ring
• Defective ABS control unit
• Interruption in the wiring
• Mechanical damage to the wheel bearing
• Incorrect air gap setting between sensor and sensor ring

What symptoms occur in parallel with fault code C1233?

• ABS warning light: The ABS indicator light lights up continuously or flashes in the dashboard
• Malfunction: The anti-lock braking system no longer functions properly
• ESP malfunction: Electronic stability programs may be impaired
• Braking behavior: Longer braking distances during emergency braking on slippery surfaces
• Noises: Unusual noises from the wheel area when driving

What symptoms occur in parallel with fault code C1233?

• First of all, a thorough diagnosis should be carried out to identify the exact cause of fault code C1233.
• Replace the wheel speed sensor: Remove the defective sensor from the affected wheel and replace it with a new one, ensuring that it is positioned correctly
• Repair or replace the sensor cable: Locate damaged cable sections, repair or replace the complete cable set
• Clean and secure plug connections: Clean all connectors on the sensor and control unit, check for corrosion and connect firmly
• Clean or replace the sensor ring: Thoroughly clean the pulse ring on the wheel or replace it completely if damaged
• Replace the ABS control unit: If the control module is defective, have it professionally replaced and reprogrammed
• Check the wiring completely: Carry out a continuity check of all cables and replace defective sections
• Replace wheel bearing: In the event of mechanical damage, replace the entire wheel bearing including the sensor ring