Fault code C1100 – a step-by-step guide to diagnosing and fixing it

Error code C1100 is displayed and the check engine light is on - what does this mean?

The DTC C1100 is recognized by the OBD system and indicates a fault in the ABS control unit or in the communication between the vehicle systems. This trouble code mainly affects the anti-lock braking system and can have different specific meanings for different manufacturers, but generally refers to communication problems or internal control unit errors.

What causes can this error code have?

• Defective ABS control unit
• Damaged cable connections to the ABS module
• Corroded or loose plug connections
• Voltage problems in the vehicle electrics
• Faulty CAN bus communication
• Defective fuses in the ABS system
• Software errors in the control unit
• Water damage to the ABS module

What symptoms occur in parallel with fault code C1100?

• ABS warning light: The ABS indicator light is permanently illuminated in the dashboard
• Braking problems: The ABS system is not working properly or fails completely
• ESP malfunction: The driving stability control may also be impaired
• Starting problems: In rare cases, the vehicle may develop starting problems
• Other warning lights: Additional warning lights may illuminate
• Communication error: OBD scanner cannot reach other systems

How to fix the problem of fault code C1100?

• Repairing fault code C1100 requires a systematic approach to identify the exact cause.
• Checking and replacing defective fuses in the ABS system and checking the power supply to the ABS control unit
• Inspection and repair of damaged cable connections between the ABS module and other vehicle systems, including cleaning of corroded contacts
• Replacement of the ABS control unit in the event of internal defects following prior diagnosis by a specialist workshop
• Software update or reprogramming of the ABS module by an authorized workshop
• Repair or replacement of damaged CAN bus lines after localization of the fault using professional diagnostic equipment
• Drying and sealing of the ABS module in the event of water damage and replacement of affected components