I've owned my 2002 55000 mls 3.0i petrol E53 for about 2 months now. It has a strange problem. Within 10 mins of starting for the first time each day whilst driving (usually downhill) the brakes appear to come on of their own accord - no DSC/ABS or TC lights illuminate. Hill descent is not on and the brakes remain on for a second then release. The revs tend to remain where they are regardless of whether my foot is on the accelerator or not but then after a second or two they subside back to idle. This usually happens once per day and then rarely a 2nd time. Searches elsewhere suggest that this might be related to a failing yaw sensor (Or possibly a steering angle sensor, if that is not the same thing as a yaw sensor) but if so this appears to be usually accompanied by the DSC/ABS lights coming on.

Any ideas as to what might be causing this. Interrogation of the OBD reveals no faults recorded?

Tks in advance.