Merry Xmas everyone! So both of my keys are not locking/unlockjng the car and the comfort access doesn’t work. I’m able use the keyless start once inside and the all radio functions work fine. Both keys have new batteries, no fault codes related to diversity antenna/CAS in ISTA+.
Do i have a bad diversity antenna? In all the videos and posts that I’ve seen, bad antenna is combined with no radio reception. Just wanted to make sure it can go bad with just the keys/comfort access not working.

 

to close my own thread, yes, you can have a working radio reception and comfort access and a dead diversity antenna, or at least dead part that is responsible for retransmitting keyfob signal. here’s what mine looked like, replaced it and used silicone around the cover to make sure this doesn’t happen again. problem solved.

 

Good update thanks for closing your issue out

 

I dont think you can fully seal the case with silicone. However there were some foaming pads to be installed around the antenna suggested by the BMW to prevent antenna from getting soaked in the water. What I also did on mine - just added a few washers on each side underneath of antenna slightly lifting it up.

 

Like the washer idea, might do that too. I added a bead of silicone on the inside edge of the antenna housing and used a very sticky weather barrier type of a paste (body shop guys call it “dum-dum”) to seal it from outside to the best of my ability, including all the connector entry points. Should’ve taken a picture of the end result.

 

Looks just like mine! :-)