Still no solution but I am currently trying to narrow down the problem to either
1) issue with the F-CAN wiring
or
2) bad electronics in the DSC/ABS unit
I'm running resistance checks on the F-CAN network and the modules where I expect to see a 60ohm reading on the network and 120ohm on the modules which contain resistors (SZL, DSC). Still need to work thru this.
Question is - Does anyone know of the location of any crimps in the F-CAN network in an E90? The reason I ask is because both the SZL and the Lateral Acceleration Sensor are connected to the F-CAN bus and only 1 pair of wires go to DSC. This must mean that somewhere inside the car one of these modules has a crimp or join into the F-CAN pair of wires.
There was a post about this but I could not get to the location of the crimps via the OP who did not know.
http://www.e90post.com/forums/showthread.php?p=16684341
I am trying to get access to the BMW OSS to see if their tech docs / wiring diagrams can give more details.