Thanks for the info
 

I wanted to jump in here and say thanks for all of the excellent information. This may be a bit long.

I recently acquired a beautiful 2008 535Xi wagon. And I mean it is stunning, black sapphire metallic car with black interior. The folks I bought it from were not happy. They had only bought the car themselves 6 months prior, but it was plagued with issues. They did tell me that they were basically done with the car and listed some of the issues to me, such as no remote usage or Bluetooth.

I had purchased a scanner capable of dealing the the specific BMW codes to help me troubleshoot. The battery would die and I eventually had to change it. I graphed the alternator voltage to realize that first things first I needed to replace the voltage regulator. That settled that, but the battery was still being drained. I then inspected the tailgate wiring and found a couple wires severed, which I repaired to no avail. I pulled the various panels to where the different modules lived to see if there was any damage. Under the spare tire were good. I then reached to the drivers side and noticed the satellite radio module had some rust. I pulled it out and did an inspection and noticed some smoke had been released. $10 later I installed an optical loop in its place and made a phone call to my wife over the Bluetooth connection. Remotes still didn't work. I believe that the unit was shorting to ground and taking my battery down with it.

I read that you need to pull the diversity antenna and give it a thorough inspection, which I did. As an electronics technician I have a keen eye for failed components. And lo and behold, there were a few SMT parts burned (damn old eyes almost missed them). So I bought one off of eBay. Once I installed it and started the car up it all worked. Everything. No alerts, error, dings or anything.

I read about all of the challenges I worked through here and I appreciate all of your thoughtful insights into these lovely cars.

Well done! I too just bought an antenna amplifier on eBay to solve my remote issue. Fortunately someone on here told me the part from a 6 series is compatible because I bought one for $35 whereas it was $250 for an E61 part.

Ahh yes, I also took the advice to look for the alternative parts. I didn't have as much as you did finding a part that cheap, but mine was only $55. That's much cheaper than the E61 ones I saw were. So far I am loving the car and can't wait to do a few cosmetic mods to personalize it.