I’ve started getting this problem which at first happened intermittently during a long journey (1 hour plus), and is now happening almost every journey. A beep, followed by both ABS and the DSC light being illuminated orange.
Using carsoft to interrogate the ABS/DSC unit returns the following:
5E21 – Pressure sensor 2 accident recognition.
There are 2 sensors in the master brake cylinder. The prressure sensor from BMW is nearly £150 inc VAT, but I found one on Ebay German for €14 and €12 shipping to the UK. Will fit and report back….
The ECU also reported:
4252 and 4262 which are glow plugs cylinder 5 and 6, so I will check the wiring, again.
UPDATE: I fitted the cheap sensor I found on German Ebay – lost a bit of fluid so re-bled the brakes and the light has gone out 🙂