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
- The valve sticks (old or dirty brake fluid)
- This wheel’s speed sensor gives a wrong signal
- ABS control unit
What you can do yourself
- With this fault ABS usually switches off: the ordinary brakes still work, but without ABS the wheels can lock. Brake smoothly and leave a bigger gap, especially on slippery roads.
- If the brake pedal has become hard, soft or sinks, or the car brakes worse — don’t drive, call a tow truck.
- Brake fluid is changed on schedule (usually every 2 years): old fluid harms the ABS valves.
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.