I've had a high battery drain warning come up twice on my car, and it's on my list of things for the dealer to check out when I bring my car in next. I do have a trickle charger which I use overnight every couple of months, and this seems to help.

I also came across this thread a few months back -- perhaps this helps?

https://5series.net/forums/topic/923...&#entry1091657

Good luck!

 

i would be very concerned for this battery drain issue, it seems to have a new thread almost daily, good luck in getting this resolved whatever this issue may be

 

Leaving the fob in will activate the first stage of the ignition which will wear down the battery. If you can get it to turn off, the warning buzzer and dash light will beep to tell you the fob is in the ignition. At least thats what my car does. To stop the lock/unlock cycle I leave the fob in the garage when I wash the car.

 

Guys, the CAS module does not refer to "Comfort Access". CAS stands for "Car Access System" and it handles tons of stuff related to the car and is present on all E60s, whether the car has Comfort Access or not.

Everything you need to know about what the CAS module does is in the following thread:
https://5series.net/forums/topic/378...post__p__46572

As far as what's wrong with ECF's car, it's clearly something either preventing the car from going to sleep or something repeatedly waking the car up at some interval. My guess is the latter, not the former. If you park the car and come back 20 minutes later and look in the window (don't touch the car) is the car asleep? If it is, try coming back and checking on it every 10 minutes or so to see if it's still asleep. I realize this is a pain in the ass but it might be worth trying it for as long as you can (over many hours, if possible) to see if the car is waking up.

 

I had the same problem, that was diagnosed as a bad comfort access handle module.

 

Thanks for the clarification Rudy. I'll try your and check on my car periodically. Sorta like how I check on my son throughout the night. haha

 

Thanks for you input - I'll have to add it to the check list for my Dealer SA so they can be certain to interrogate that component.

If that was at fault, and thanks Rudy for the informative pdf's, I suspect that may have permitted my car to think or tell the ignition it should be left on and subsequently drain the battery!

 

Well I tried what Rudy suggested by checking on the car periodically and didn't see or hear anything. Just took my car back to the dealer today for the fifth time. Having them check comfort access door handles. I have a feeling they're going to reprogram my car as well. What a pain.

Since I'm not the original owner (bought it used back in early 2007), am I SOL on trying to lemon this car? I'm more curious than anything else since I love this car and have put so much time and energy into it that I can't imagine getting rid of it this way.

 

Sucks, but I think you can only lemon a car when it's under the original 4 year warranty (not any CPO or extended)... Maybe the alternator?

 

Not alternator. That was one of the first things they checked.