[535gtxenon]

Water leak from the shark fin cover on the roof into the telematics control unit (TCU) causes damage to the TCU then leads to the warning sign of "emergency call malfunction" as well as lost of navigation is not uncommon among G05 X5. For me this is the second time I had to replace the TCU. There are several threads on this topic here, but none is conclusive on the coding side. I thought my case is a typical example of the water leak causes the TCU dead and I took some pictures as I was replacing the TCU, so I will make a DIY guide for anyone who wants to do the TCU replacement DIY.

First of all, you most likely need a reprogramming/coding if you change out the TCU.

Thanks to @tkhater (https://g05.bimmerpost.com/forums/sh....php?t=2050687), getting to the TCU was not difficult, but I also took some pictures while I was getting to the TCU, so it should make it easier for followers.

1).Open the side panels in the truck. You can just pull these 2 panels off without removing the sealing around them. It is straightforward to do.

2). The headliner can then be pulled down, it is anchored by 2 plugs.

3). That will expose the TCU. There are about 5 connectors. Before you unplug them, you need to detach the TCU from the roof/antenna by pulling on the tab in the center of the TCU and then move the TCU towards the front end of the car about one inch. It will detach and fall from the roof. You can then start unplug the cables.

4). Replace the TCU, or just replace the battery inside the TCU to see if only the battery is dead. In my case, replacing the battery did not fix it, and there was som much water damage inside the TCU, I just replaced both.

5). Remove the shark fin cover from the roof outside the car. Because my TCU was already replaced once under the warranty, so the fin cover was sealed to the roof. It was actually the hardest part to pull it off the roof. Nevertheless, the technician must have failed sealing the cover properly as water was everywhere as shown in these photos.

6). Last, after the TCU is replaced and put back, fin cover is sealed. I called a couple of BMW dealers about reprograming. They are all familiar with this problem, and provided a quote. I ended up with the nearest dealer who charges about 200 bucks for whole car programming.

Overall, TCU was about $530, battery $65, both bought from a BMW dealer. Reprogramming about $200. Once this is done, I got my navigation back. Speed limit detection on the HUD back, and comfort access on all doors back (I lost camera detection for speed limit on the HUD for some reason and lost the comfort access on all doors except the driver's door which I guess due to the signal going through the antenna connected to the TCU). Thanks to other members on the forum, replacing the parts on the car was actually easier than most DIYs I have done on bimmers. Reprogramming was also reasonable at $200.
But it is clear to me that BMW did a poor design job here. IMO, there should be a recall because of the flaw in the design.

[MADBMWX5MC]

One idea (also mentioned in the other post) I've done on my SRT is placing thin bead of silicone around it. Thin enough to cover the junction between TCU and roof...if I need to do anything, I can always remove the silicone vs having water seep in, then having this nightmare.