Just an update on this...
Got a used epb sitting waiting to be put on BUT...
After staring at my reader for too long some things popped out. Checking live data my steering angle was 3oo n odd degrees while driving in a straight line ! My yaw rate jumps from -20 to +30 while parked and my lateral acceleration sensor is reading 0.5 mph while also parked
I presume those readings are all linked ?
I have " fixed" the ring that the sas picks up back to the steering column ( as it was flapping about, loose ). Will calibrate this when the araldite has dried lol.