I'm having this reoccurring 4x4 error pop up when I make turns in my 2006 330xi (E90). It used to happen the most when I make slow speed, sharp turns as in parking garage maneuvering. It used to happen primarily in really cold weather, but now it happens all the time. Turning off the car, pausing, and turning it back on either clears the error immediately or after a few minutes of driving relatively straight. Hitting the cruise control while the 4x4 error is up also pops up another error stating that the cruise control has malfunctioned. This error also goes away upon restart. I have the same thing happen with both my factory staggered performance tire/wheel setup as well as my squared winter tire/wheel setup. This is the last season for the PS2s on my summer setup, so I wonder if that might have something to do with it. However, they aren't abnormally worn. Both my independent shop and the dealer were unable to find anything wrong in the past, and no error codes were stored. One of the problems I have is that the error usually disappears before I get to either shop. I also haven't been able to find anything in the Bentley Repair Manual. I've heard that a faulty steering wheel angle sensor could be to blame. Any ideas? This is getting really annoying.