I had to have my battery replaced ~29 months into my 08 535i with ~16K miles on it....they did not state if there was a faulty module nor did they bother to check AFAIK. With less than 1 year left on this lease, I hope the next owner does not come across this problem, but worried he/she will. Unfortunately I don't have the luxury of leaving my car at the dealership for x amount of days hoping the service tech can diagnose the problem. So I am keeping my finger crossed and glad they swapped out my battery...

 

My 08 535 battery drain problem was found to be "poor driver profile" until I got angry and said a few things I don't normally say. Dealership put the car on a monitor for 4 days and nights only to find out the TCU (Telemetric Control Unit) woke up everynight about midnight searching for my Iphone - thus draining the battery.

The TCU was replaced and, at the same time, the Dealership upgraded my battery to the AGM. No problems since.

 

Some of the best comments on this issue are in this thread.

I guess it was Rudy who suggested that BMW doesn?t know which module (or what ever) is causing the problem so they conjured up the ?driver profile? excuse.

IMO that is hard to believe and I might offer that they have indeed identified the cause of the problem but they are unwilling to admit it so as to avoid a costly fix. Logically, that is safe for them because the high user drivers don?t seem to have the problem.

I probably will not ever own another Bimmer (or any car for that matter) but I will be watching my 5series.net to see if BMW has addressed the issue successfully on the new generations of 5ers.

This is a not battery issue as some have suggested,on the LCIs, IMO.

As much of a pain in the ass it, is my problem has been solved with my B&D float charger.

sixcard