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      04-22-2011, 09:08 PM   #1
yikes98
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Drives: 17'F15,11'E90,07'E92,96'E36,20
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My $0.02 Steering Angle Sensor Fix

BMW 07’ 328i e92
My $0.02 DIY Steering Angle Sensor (SAS) Repair

First, thanks to all who posted on their SAS problems and pics. Using all that info I was able to piece together how to attack my wife’s dreaded DSC faults on her 328i. The stealership, opps I meant dealership quoted me $1101.00 to RR the SAS including programming (what a deal huh?). Here is my $.02 fix for your enjoyment. Be very carefully as many components are small and fragile. PC type electronic component repair skills very helpful. Use this at your own risk as I guarantee nothing.

1. The dreaded DSC faults, pic#1 & 2.
2. Disconnect negative terminal on battery (in the trunk) and wait 10 minutes or so to let all caps discharge.
3. Remove airbag. On each side of the steering wheel at 4 & 7 o’clock position there are small slits on the surface, put a straight torx driver or allen key into. Feel for the spring and push to release the springs, pic#3 & #4.
4. Carefully pry connector tabs and pull upward to release locks and remove airbag connector’s, pic#5.
5. Remove the two connectors near the top of the steering wheel. Using a small screwdriver release both tab releases, they are on top of the connector, pic#6.
6. Remove steering wheel bolt. The torque spec is 46 lb-ft, pic#6.
7. Remove steering wheel, note the index marks at the bottom, pic#7.
8. Now comes the hard part, splitting the steering wheel cowling. Carefully pry the inside and outside of the cowling split to release the circular tabs, pic#8. I used my fingers and screwdriver. Remove the lower cowling and lift the upper one out of the way, pic#9.
9. Remove the 4 torx bolts that hold the switch assembly that houses the infamous SAS pic#9. Remove the two connectors from the back; one is a tab release the other a lever release.
10. With the switch unit steering column assembly removed pay a BMW dealership a crap load of money for a new one ($573.14 or more) and then pay more money to them to reprogramming the module. WTF I thought this was a $0.02 fix??? Just kidding on the BMW dealership thing….
11. Remove the clock spring assembly 2 tabs on the top and bottom and a tab release near the bottom of the connector. It will lift off as a whole assembly, pic #9. Don’t remove the clock spring cover tabs.
12. Put the assembly on an anti-static pad and attach yourself to an anti static strap. Note the indexing marks to the left of the unit, pic #10. Remove the SAS sensor housing cover, slowly working the tabs free. Now you should see the optical disc, pic #11.
13. Remove the IR LED cover using a t6 torx driver. Then remove the optical disc by squeezing the tabs on the back and slowly pulling the disc off the assembly. The optical disc on the face side looked like it was coated with a protective coating that deteriorated to form some crystal like stuff. This was not the problem but I clean it off with meguiars #10 clear plastic polish. Leave the back side alone as it is etched with the encoder information, pic #12.
14. Definitely do this at your very own risk. Remove the 3 torx screws on the pc board. Slowly lift up to expose the three ribbon cables underneath. Using a small needle nose pliers pull the black cable releases down and away from the connector. The cables should be free. Pull the pc board out of the assembly, pic #13 & 14.
15. The IR LED and sensor pickup is shown in pic#14.
16. Using an IC type tip soldering iron (very small tip pic#15) reflow the connections for the IR LED and sensor. I also did a bunch of components on both sides the board just for fun. Shotgun soldering to fix the cold solder joint problem. (Update: soldered the press fit pin connectors for the main wiring harness and jumper on the right side of the control board after the error came back after 6 months, cleaned and reassemble, no problem since. 10/11) This was the problem on my board and the solution to many intermittent electronic problems (i.e. the 3 red rings of death on my son’s XBOX360).
17. Reassemble in the reverse order note all index marks. BTW here is pic#16 of the IR LED on with the cover removed. Can’t see infrared light with the naked eye you say, hmmm my super sophisticated CCD digital camera can (pretty much any run of the mill digital camera can). Sorry for the fuzzy picture, it was hard trying to take the picture while holding a black garbage bag to block the sunlight.
18. No reprogramming the module, just keeping a grand or so in my pocket for other fun stuff. (Update: After reconnecting the battery, make sure wheel is centered, start car, turn full lock left, then turn full lock right, re-center steering wheel, SAS is re-calibrated).
19. It took me longer to write this and edit the pics than to actually troubleshoot and fix the problem. Now the turn signals turn off automatically again, cruise control works again, headlights tracks the steering wheel again, and start–off assistance works again. No fault codes on DSC/DTC. DSC/DTC works when I pull away from the car wash. Wife happy, life is good.
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Last edited by yikes98; 01-02-2012 at 11:29 AM..