Hi, I have an 05 M535d sport and the i-drive button has stopped working (can't turn it or press it), I have bought a new one and was wondering if someone that knows how to change it could talk me through it please? Maybe step-by-step instructions? Does the whole dash need to come out? Will the new system need coding? Would be very grateful for any replies, thank you!

 

If you mean the iDrive controller on the center console - here is a basic how-to from memory:

First, you need to remove the shift knob - if you have automatic, simply pull straight up on the knob very firm - careful not to punch yourself in the face. If you have manual, I don't know how it comes off, but if you get stuck here, I caution you not to proceed further.

Second - remove the surrounding trim form the shifting mechanism. There will be two harnesses beneath this trim panel, one white and one yellow if memory serves.

Now that you have removed these two, pull off the iDrive knob by pulling under one side of it - it comes right off, no need to worry about damage here.

Next step is to remove the console trim, this is done by removing the 4 torx bolts you exposed when removing the shift bezel. Then you need to apply firm and slow pressure under the trim not allowing one part to get more than 3/4 of an inch higher than any other so you do not bend or crack the trim.
You can use your fingernails (riskier version) or some sort of plastic plaster knife to get under this trim, I do not suggest you use anything metal. As you remove this trim, be cautious of the iDrive menu button, it is attached to this trim - disconnect the harness from under the button once you can reach it.

Once this top piece is removed (ashtray door comes with it) you will see that the iDrive controller was maliciously bolted in from under the console. Now it is time to gain access.

Pull the trim panel from the back of the console that contains the two 12v outlets. This will require force and patience the first time because your mind does not want to believe it will come out without damage, but it will. Use something soft to pull one side and get your fingers in there. Sometimes you have to just break it loose with a firm tug.

Once you remove this panel, you can look inside the open hole and see two bolts in the corners closest to the rear. I believe they are 12mm, I may be wrong, but this is unimportant because you should have many sockets. Remove the rear bolts.

Now get in one of the front seats and adjust both seats all the way back, you will need the room. Look on the side of center console where the 'leather' surface meets the carpet flooring. There is a carpeted piece of trim that need to be removed, you do this by putting your fingers behind it from the underside and pushing the piece towards the back of the car gently about 2 inches. (Sorry for the imperial madness)

Do this on both sides and you will now have exposed two shiny silver bolts at the far lower front sides of the console. Remove those.

Now the console is unanchored, but not completely in the clear.
next, I suggest pulling up on the e-brake as hard as you can, and then firmly pull the leather handle off the e-brake lever by pulling it forward. Do not worry, you will break before it does. The e0brake boot will come forward at this point, but the base of it is still connected to the console. I noticed that you could technically manipulate it completely off, but to me it felt better to wait until a later step to get access from the underside which comes soon.

Now that you have unanchored the console, you will notice it is loose and can move up and down a bit, this is good. But don't move too quick or you may break something. The front, top of the console there the ashtray is secures to the radio console with plastic that fits together when the console was put in. I know that sounds confusing, I am doing my best without pictures to illustrate - but you need to pull the console up in the rear of it while leaving the front down, and pull the whole assembly back a few inches in order to have enough clearance to pull the front up. behind the ashtray is a two wire harness with a (white?) plug, disconnect this.

At this point you have a semi-operable platform for removing and replacing the iDrive controller. I have done this a few times and often at this point I raise the console as high as it wants to allow me and do the work by feel. If you reach under you will notice with your fingers 4 torx bolts, wish I could tell you the size but I never remember. You'll figure it out, don't forget to remove the wiring harness to the controller before unbolting.

Test functionality before reassembly. technically the new iDrive controller will need to be coded to the car, but 99% (arbitrary estimate) of the time it will work without coding. Just make sure to inform your dealer you made this swap before any major service or coding - otherwise the module will throw errors and the coding will fail.

My advice is to remember to route the iDrive menu button wiring harness back up to the top before you bolt the console back down it is easy to forget when your car is in this state of modification.

I may have left out a few steps, but this is the gist of it. I may have even wasted my time because as I was typing this I felt like I remembered seeing a DIY on this a while back. Hopefully someone with equal or more experience can chime in to fil any holes I left in this process.

thanks for reading.