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Steering angle sensor DIY fix - it worked

431K views 144 replies 60 participants last post by  Deleteduser  
#1 · (Edited by Moderator)
A few weeks ago, my car exhibited classic steering angle sensor (SZL) failure symptoms - at the first instance of turning the steering wheel after starting the car, I'd get errors indicating falts with the DSC and the FTM. I'd read about this fix My $0.02 Steering Angle Sensor Fix - BMW 3-Series (E90 E92) Forum - E90Post.com a while back, and decided to try some aspects of it before giving my car up to a mechanic for a day or so.

Specifically, I pulled the steering angle sensor, opened it up, and cleaned the top side of the optical disk with glasses cleaning solution and a lint-free, super fine weave, microfiber glasses cleaning cloth. One of the posts recommended isopropyl alcohol, which I did not use because alcohol can craze some types of plastic and the optical disk is plastic. The glasses cleaning solution said it was safe for plastic lenses.

There was, in fact, a nasty brown film on the disk. I thought about cleaning the bottom side of the disk (the side with the pattern deposited on it), but I was worried about damaging the pattern, so I didn't. I also unscrewed the clear block that transmits light from the LED (it needs a tiny, maybe T-8 Torx driver). It was a bit yellowed (not crystal clear looking), and the cleaning didn't seem to change that.

I did not try to reflow any of the solder connections.

I put it all back together and drove it around on and off Sunday and to work this morning. I've not got the error again. I'm not saying that it was the cleaning that fixed it. It could have been that I'd had a loose connector. However, whatever I did seemed to have fixed it.

Some things to know:
  • The DIY linked above is for an e90. Our e60s are a bit different. The steering angle sensor looks the same and is in the same place, but getting to it is a little different. If you're mechanically inclined, it is not hard.
  • You don't have to re-code the steering angle sensor to the car if you do this, because you're changing anything.
  • Some early e60s had the clear block over the LED changed.

Therefore, you can order a new one. If my issues come back, I might do that.
 
Discussion starter · #4 ·
Now instead of being a tease, post step by step instructions (with pics) on how to remove the SZL for an e60 since you have our attention.
It is too late for that, but the differences were really nominal. For example, to release the airbag, you put a screw driver into the back of the steering wheel and compress a spring. The e90 write up showed two holes to access the spring. Because we have SMG paddles, there's only one hole to access spring. In another example, the clips that hold the top and bottom halves of the steering column cover are of a different shape than those in the e90 write up, but like the e90 clips, they come apart by prying the top and bottom halves apart. In yet another example, the Torx screws that hold the unit in place are in slightly different locations in the e90 than they are in the e60.

In short, once you've seen the e90 write up, performing it on the e60 is easy.
 
Discussion starter · #24 ·
Great diy thread, i was wondering if the problem has come back at all or has it been problem free since the clean up. I have the same problem, mine comes on and goes off while driving and goes off and stays off after every shut down and start up , until i do a few turns and it pops back up.
Mine has been problem free since my original write-up in April.
 
Discussion starter · #53 ·
You must not have got all the clips or screws. Mine came apart quite easily. I'd be surprised if yours was glued.

BTW, a year and a half later, I'm still SZL error free. The cleaning was a fix for me.