Z4M Steering Angle Sensor Replacement

[Shipkiller]

Today was car repair day.

Over the last three or four months, I have been getting intermittent DSC errors for the Steering Angle sensor (SAS). The specific errors on the instrument cluster were: Amber DSC and Amber Brake lights.

Sometimes they would clear (after a restart) and sometime I had to clear the errors using software. INPA, ISTA/D and Rheingold would report a “90’ implausibility error”.

The faults would come and go, leaving for weeks, sometimes… until they finally stayed faulted.

This was not a catastrophic error. It only meant that the DSC would not work. This is not a life ending event.

So I ordered a SAS, received it on Friday and started the repair Friday evening and into Saturday morning.

I am not planning on delineating a step by step. The TIS is pretty good in this case. There are some things I found that would be very helpful.. On a scale of one to 10, I would say it’s a five. Easier than doing a valve shim.

The TIS procedures used: (these are almost in order of use)

32 31 070 Removing and installing/replacing steering spindle lower section (S54)
32 33 001 Removing and installing/replacing steering wheel
32 31 020 Removing and installing / replacing lower section of steering column trim
32 31 003 Removing and installing/replacing upper section of steering column trim
84 31 540 Removing and installing/replacing handsfree microphone on steering column
32 31 102 Replacing steering spindle sleeve (DOES NOT NEED TO BE ACCOMPLISH)
32 31 090 Removing and installing/replacing steering column (S54)
32 31 Steering Column Torque value sheet
32 33 Steering Wheel Torque value sheet

The TIS does not say anything about removing the driver’s seat. I did not do this but if I had to do this again, the driver’s seat is coming out of the car. It only takes 15 minutes to remove the seat and it will make the job 100% easier..

I put the front of the car on jackstands. This is because 32 31 070 says to remove the intermediate shaft at both the upper and lower couplings. To remove the lower coupling, you have to remove the reinforcement plate under the car. I found that removing the lower coupling was not needed, so did not do that part of the procedure.

Disengage the battery from the car. You have to remove some airbags…..

NOTE: During the next step, the steering shaft will NOT move because it is still bolted to the dash.

I removed the bolt from the upper shaft coupling. The bolt has to come completely out of the coupling. I then used a 90’ offset screw driver to try to gently push the coupling off of the steering shaft. It’s still a little tight.

I then used the same offset screwdriver to pry the compression coupling apart a millimeter or so to allow the steering shaft to move freely.





Now to remove the steering wheel air bag, steering wheel and remove the upper and lower steering column trim and the foot well trim.




Now using 32 31 090 start getting the steering column ready for removal. You are going to have to cut some tie-wraps.

Tech TIP: Take some WHITE tie-wraps and place them at each location where the OEM tie-wrap was located so you have a visual indicator where to place the new tie-wrap when you reinstall the steering column. DO NOT USE YOUR MEMORY..

You may want to remove the foot well air bag. I did not and it was a little difficult to remove and reinstall the rear steering column bolts. This is up to you.

Once all the electrical interference is out of the way, start to remove the eight 14mm bolts that hold the steering column in place. The two FORWARD bolts should be removed then reinserted about four or five threads.. This will help hold the column. You will see why on down in the pictures.

Once all the bolts are out, support the column and remove from the car..





Now use 32 31 082 to replace the SAS.





Reinstallation is even easier.

After everything is back on the car and reconnected, start the car. You will still have the DSC and Brake errors. You still have to code the new SAS to the car and have it zeroed.

With the car running, look for any air bag lights. If you have any, turn everything off, disconnect the battery and recheck your connections. These errors will also have to be cleared with software.

If you have NO air bag lights, then turn the steering wheel full lock to lock and check for air bag lights. The TIS tells you to do this.. You are checking to see if you damaged your ‘clock spring’. Low probability...

No error lights? Good. Everything is well.

Now reinitialize your windows. If you do not do this, when you read module errors, the GM5 module will show a non-indicating error for ‘Window Initialization”.

Now code and zero the SAS.

Done.

[Jstic]

Great job and definitely by the book, but I found an easier way to do mine. If you take the rubber trim out of the firewall where the shaft goes through, you can slip the entire SAS right off the shaft, through the firewall and off.

Photo is of steering column shaft where it goes through firewall(minus the rubber sleeve at firewall).

My car is not an M, but I am assuming that the drive shafts are similar.

[Shipkiller]

I actually thought of that way. But when I attempted it that way, I could not get the split ring off, not enough room for me with the seat installed. Then I thought, if the split ring is that hard to get off, then it would be doubly hard to get on without damaging it.
Plus, getting the carpet out of the way was problematic without removing more interference.

Your way is doable with the seat removed..

There are always more than one way to do a job.... Glad to see someone did it the way I originally thought of but then I discarded the idea.

With the seat out of the car, this job is really a two hour job. With the seat in the car it was a six hour job. Learned something for next time....

[Jstic]

I did have the seat out and was working on my back under the steering column. With the seat in it was just about impossible to work in the tight space. Something else I just realized, my car is an auto so no clutch pedal in my way. If I remember right, I used a heat gun to heat up the rubber ring and that made it flexible enough to move around. I really did NOT want to remove the steering column. I give you credit for taking it out and replacing it without issue. The dealer wanted $1300 plus the cost of the SAS to do mine using the steering column removal method.

Question for you SK, were you able to remove the metal tang at the end of the shaft to get the white bushings off? I had a heckuva time with that piece, one of the disadvantages to not taking the steering column out.

[Shipkiller]

I did not think that was a Z4. The steering shaft was too rusty....
The black 'keeper' at the end of the shaft is plastic and the new SAS has one in the package, plus new bushings. I just pulled it out with a pair of pliers.

There are pros and cons to each method.

I was very surprised on just how easy the steering column was to remove. Like they planned it.. ..