A fault code doesn’t yet mean the unit or sensor itself is faulty: often it’s the plug and connector leading to it.
Possible causes
- A fault in the engine control unit (sensors, throttle)
- The CAN bus between the engine unit and the ESP unit
- ABS control unit
What you can do yourself
- ESP and traction control, and sometimes ABS, may not work. The brakes still work, but without electronic help — on slippery roads brake smoothly and don’t accelerate hard.
- Read the engine control unit codes: ESP and traction control often switch off because of an engine or throttle fault.
Stop and don’t drive on if:
- The red brake light is on, or the brake pedal feels soft or sinks
- The steering became very heavy, or the car pulls to one side when braking
If the scan tool shows the code with a suffix after a dash (for example, C0031-1D), that’s the fault detail: 01 — general electrical failure, 1D — circuit current out of range, 29 — invalid signal, 2F — erratic signal, 62 — signal doesn’t match the others.
The explanation comes from the error code reference in the AvtoElektrik PRO app.