If ever you get the Dynamic Drive system shut down with out all the added ABS lights then most likely it is an issue with the SZL. You will get the Drive moderately warning on the iDrive screen. You may also (not always) have an issue with the turn signals not turning off after making a turn.

The cause is usually the brushes inside the steering position sensor. IPNA will display this reading and you may also get a fault for it. It can affect other systems as many systems use the SZL readings.

There are two ways you can do this. You can replace the whole unit with either a new one (expensive) or a used one (you should inspect the used one before install), or you can do what I did and just replace the brushes in the unit. I picked up a used SZL from a local place (Bimmer Motor World in Winder GA, check them out on ebay and Facebook) and disassembled it and used the bearings and sensor ring from the used unit in my SZL. This lets me avoid having to VIN code the SZL to my car as I did not change the whold unit. Since I was removing my steering wheel in my 05 pre facelift this was a good time to swap in a newer steering wheel (in better shape) and airbag.

First I disconnected the Battery 20-30 mins before I started to make sure the power was dead before disconnecting the airbag. I will share some of my photos but there are many videos on youtube on the process.

Here you can see my 05 wheel was in rough shape on the top.

The airbag pops off. There are spring loaded locks you need to push off from behind the wheel with a screw driver or in my case I used a long allen key. The 4 spoke wheels have two one on each side, and the 3 spoke sport wheel has one in the bottom middle. I found it best to turn the wheel so hole was under the steering shaft to give me some room to work. Lots of videos on youtube on how to do it.

Removing the 15mm steering wheel bolt was a little difficult the first time as it was really on there. I had to use a 2ft breaker bar while trying to apply back force on the wheel to keep it from turning.

Unplug the steering wheel control module and then simply pull the wheel off. This is by far the easiest car I have ever removed a steering wheel in. It will also only go in one way so no need to worry that it wont be positioned correctly when its time to replace it. It is best to center the wheel before removing it, you can see there is a lock for the sensor at the top that keeps the sensor in place when the wheel is removed.

Next remove the cover panel so we can get to the screws and remove the SZL. I believe it was 3 T20 bolts holding it in place. All of the stalks are screwed to the SZL so no need to remove these, they will come out as a whole unit.

Next we will disassemble the brush mount and bearing.

On the inside you will have two clips that hold on the clock spring assembly, just use a pick tool to pry apart while gently pulling up on it.

With the clock spring removed now we can pull the bearing and brush wheel. This is held in by a plastic holder, it has 3 tabs on the inside that need to be gently pried up while pulling it out.

Now we can gently wiggly/pry the bearing and brush wheel out. The brushes are under the two large tabs, you will need to rotate so that theses are at bottom before prying as you can see there is a ridge at the top to keep them in place.

Here you can see both of my brush sets are completely gone. This is a common issue in our model. Later models (F01 etc) switched to an optic steering position sensor.

This is the piece out of my replacement. This is how these brushes should look. The SZL I got for parts came out of a facelift model, as you can see the slightly modified the design to last longer and be stronger.

Before Reassembling I took some q-tips and gently wiped debris off the sensor track.

I also used the clock spring (replacement had heated wheel, the clock spring is different but SZL is the same between heated and non heated wheel setups) and some of the control stocks from the facelift model as they have a nicer finish. These plug right in and nother other changes is needed.

You can see the finish difference here, pre facelift is top, facelift is bottom.

With the SZL fully reassembled time to put it back in the car.

The pre face airbag will fit the newer wheel however the wheels are shaped different and it doesn’t look right and there are larger caps on the 4 arms.

Here is the newer steering and airbag in place. I used IPNA to clear the code and check the sensor reading. At the time I am writing this it has now been a month with no more suspension or turning signal issues.