A 'generic' code reader is a valuable tool no doubt, but it is no match for ISTA/D. Why not buy a $10 ebay cable? Often times they come with the software.

You will need to solder some pins, but I can definitely confirm it works! https://xoutpost.com/bmw-sav-forums/...ml#post1135510

Then diagnosis is easy peasy - just read the live data coming out of your ABS sensors, roll/yaw sensors, steering angle sensors.

If one or more of them don't agree with reality, you know where to start. PM me if you need help.