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 brake fluid leak or air in the system
- Badly worn brake pads
- The piston position sensor
What you can do yourself
- Stop in a safe place and test the brake pedal: if it’s soft, sinks or the car brakes worse than usual, don’t drive on — call a tow truck.
- Check the brake fluid level in the reservoir and look for fluid traces at the wheels and under the car.
- The brake system needs a scan-tool diagnosis and a check for air in the brakes.
The explanation comes from the error code reference in the AvtoElektrik PRO app.