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 brake or hybrid system unit
- A valve in the brake unit
- Low voltage: a flat battery or corroded terminals
What you can do yourself
- On a hybrid or EV the electric motor does part of the braking. With this fault the car may brake less on the motor than usual, so you’ll need to press the pedal harder.
- If the brake pedal has become hard, soft or sinks, or the car brakes worse — don’t drive, call a tow truck.
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
OOleg’s tip: check the connector
Often the cause is simple — there is no contact in the connector (plug). Look at the connector from the back: remove the rubber seal and you will see whether a wire is corroded or has come off completely. Corrosion shows up as green deposits. Ideally, gently pull each wire towards you one at a time: a sound wire stays in place, while a corroded one simply comes off — it needs to be repaired.
Unplug and inspect connectors with the ignition off.
The explanation comes from the error code reference in the AvtoElektrik PRO app.