TLDR: Neither I nor my shop can find what the issue with my DSC is
My 2006 BMW X3 146k is limping along. I am trying to get rid of the annoying "holy trinity" of lights. My work started with a clunking front end when driving and the 4x4 DSC and ABS lights coming on with the clunk. I got rid of the clunk noise when I replaced all 4 calipers, and both front CV axles. The front passenger CV axle had broken at the U joint. While doing this work I managed to break one of my wheel speed sensors. I replaced it with a wheel speed sensor from O'Reillys. I believe it was the front left.
I have now been chasing the codes that still come on the dash whenever I gas medium or brake medium. The car gives a slight hesitation when it gives this fault condition and the lights on the dash come on with a beep. Ive verified that the wheel speed sensors are reading correctly by plotting a graph of the sensors readings.
The codes that my scan tool currently bring up are 5DEC transfer case malfunction, 5E5C Wheel speed sensor direction-of-rotation detection, and 5EB1 steering angle sensor supply.
I have tried taking the car to my local shop, a reputable mechanic I trust a lot. When I first brought it to them they said that the SAS was far out of alignment, that they reset that and the problem should be fixed. The light came on the next day. They said they were unsure of the issue and they proceeded to do the free transfer actuator repair seen on here
. They gave me the car back and the light came back on the next day. I brought the car back, they held the car for a few days, I didn't mind as they hadn't charged me for the work on the actuator, and then after about 5 days they said to come get the car. They said that they're pretty certain its the transfer case itself, and advised that I continue to drive the car until the transfer case fully breaks, rather than pay 2k right now for a new one.
I would really like to get a full answer of the problem, Im more than willing to try any and all diagnostic suggestions but I've really ran out at this point. Any help would really be appreciated.