I had intermittent DSC & 4X4 errors. They would clear if I stopped engine and restarted. The straw that broke the camel's back, was being 8 hours from home and not being able to clear the errors. My cruise control would not work with these errors. This was a LONG drive home w/o cruise.

I don't have active steering, but all of those systems depend on knowing the direction the driver is attempting to go.

I had a similar SAS error. Cleaning sensor was the first step and system has been error free for 2 years now.

There is a DIY on removing E70 steering wheel, airbag and column switches.
There is an E60 DIY on disassembling and cleaning the SAS.