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.
Another dissection! OK, so it was the steering wheel angle sensor. The dealer confirmed this but wanted $1350 to do the repair. Despite this being a problem that they couldn't track down when the car was still under warranty, BMW NA denied a good will repair. My independent shop got the job done for $830, the only problem being that they had to take the car with the new unit installed to the dealer to program with the uber computer. Otherwise, it would have been a $730 job. I found the sensor itself online from Tischer for $450 shipped, but the shop wanted to use their own source. So, of course I took the old one apart. I was surprised how simple the part appears to be. First of all, everywhere I asked said you have to get the whole steering wheel cluster, not just the angle sensor. I think that with a bit more digging, you could probably get the center section apart from the control arms. All three control arms (marked with red dots) appear to be modular and have individual stickers with numbers. I don't see why you couldn't pop these off and put them on another unit, providing this wouldn't affect programming, etc. Taking the thing apart is easy and requires no tools. Plastic tabs hold everything together, and they can be disconnected easily with fingernail or pen if your fingers are large. Looking inside is that really got me. The disc that the sensor reads had obvious crud on it. What this crud is and how it got there is a mystery to me. There are no fingerprints, no drip marks, etc. It looks like something wet was once there and then evaporated to leave this crystal-like formation. $20 says wiping this off and putting it back in the car would solve the problem. Of course, this could very well be unique to my vehicle and situation, or I could be completely wrong altogether. Still, a lot of the time, the simplest explanation is the correct one, and for the $830 I spent on this, I think I would rather have taken this apart myself first and towed the car to the shop if I screwed it up or required reprogramming. My $.02. P.S. I just used my Canon SD750 point-and-shoot for the images. It's surprising what you can do with macro mode!
I do believe the days of the classic car are officially over! In 20+ years these current BMWs will be a nightmare to work on. I would guess anyone will be able to do the programing of them, but will BMW continue to make all these specialized parts? That is one complicated steering wheel cluster! I would guess you are right in that if you cleaned that up with a solution it would have worked normally again. Thanks for the pictures!
