So i bought a 2005 MCS from a friend that was a rebuild. The car is relatively low miles with only 40K on the clock and mechanically, runs perfect. The dash; however, is lit up light a christmas tree and I'm tackling them one at a time.

I have yet to have the crash data cleared out, but new crash modules have been installed.

My current undertaking is with the ABS/DSC system. I have the classic trifecta and have bought a C110 BMW scanner to help diagnose the issues. I have a faulty 'Steering Angle Sensor' and front driver-side 'ABS Speed Sensor'. I purchased a new ABS sensor off eBay and after replacement, the error code still persists. I checked the live datastream for that wheel while rotating and there was no input.

I then swapped the (working) 'ABS Speed Sensor' from the front passenger-side to the front driver-side and checked the live datastream while rotating and the speed registered, but the error code still persists.

I moved the (working) 'ABS Speed Sensor' back to the front passenger-side, checked the rotation speed (working), but now I'm getting an error code on the front passenger-side as well.

Why am I not able to clear the code if the sensor is installed and properly registering speed?

 

You could be having issues with the tone ring on the wheel bearing, which is what the wheel speed sensor is using to judge wheel speed.

Was the SAS damaged in the accident? We have seen many cars that come into the shop with SAS fault codes without DSC/ABS issues.

 

I was able to get the (working) speed sensor error code to clear after resetting the system. I removed the DSC fuse, turned the key to the ON position, waited for all the lights to stop flashing, turned the car OFF, replaced fuse, cleared the code with the scanner.

As for the SAS, the housing was cracked so I'm assuming its internals are damaged. I do feel its just the sensor as when I unplug it, the scanner recognizes that it's missing and displays a different variable rather than the stuck value when it is plugged in.

I am waiting to pick up a new speed sensor for the faulty driverside before I really tackle the SAS issue.