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 actuator motor on the caliper
- The connector on the caliper: dirt, water, road salt
- The wire to the caliper is chafed
- The caliper mechanism is seized or rusted
- The electric parking brake unit or its fuse
What you can do yourself
- If the parking brake won’t release, don’t drive: the brakes will overheat.
- Check whether the wheel on this side is getting hot: a hot disc means the brake isn’t releasing.
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.