Sorry to hear about the headaches Tony. Hopefully it's the comfort access handles..

I hope you don't have to get rid of the car, or else we won't have another ECFest! (Ya I'm a selfish bastard like that)

 

A bit late with my 2 cents but does the car ever go to sleep? When I ran a sound shop a while back, I had a E66 745li come in with a cut fiber-optic line to the DVD navigation in the trunk that spun all the time due to the disconnect. When the other sound shop installed a JL Audio Clearsweep to install subs in the trunk, they weren't careful. The owner went to the dealer and replaced battery 3-times. My chief tech found the cut line and we patched it and voila! No battery drain. Long story short, if the car never goes to sleep, it's a sure sign that something could be still spinning.

 

The dealer has said that they've checked for any and all possible drains overnight and have not found anything so I assume that means the car does go to sleep. I'm hoping they'll check again.

 

hmmm... odd. Not sure if the dealer is doing the sleep test correctly. in all the late model BMWs, there is some interior light indicator that tells me that the car is asleep. For example, on the E65, the button for the bottom seat cushion on the center console stays lit until the system shuts down and goes to sleep. It could be anywhere from 3-5 minutes depending on what's going on with the car. In my E60 with the SMG, the gear indicator light tells me the same thing. On the other E60s with auto tranny, the gear indicator light on the shifter stays on to do the same. think back to when you first started noticing the problem. Are you sure your car was going to sleep? Just a thought.

 

I've checked on the car on several occasions and everything is off. I even noticed the lights on my SMG gear level going out and staying off. I looked at all the interior bulbs too per a suggestion on another forum, to see if there's a small glow of some sort and nothing. No sound either.

I just got back from the dealer and talked to the foreman. He said they've measured the car for drains overnight and found nothing yet the warning would still come on. The car even started after sitting for 3 days although when this issue first started happening, I did have to jump start it at one point. Per my request, they are going to check the comfort access door handles next and then will most likely reprogram the car if that's not the issue.

 

Sounds like you've done all that could be done on your end. It might just be as simple as clearing all the fault codes in the memory. Comfort Access could be the culprit but if your sleep light does go off, I don't think that's it either. I have an E65 with comfort access and car wakes up when I get close to the car with the key in my pocket. If any one of the sensors are broken, the sleep light would stay on perpetually. Good luck!

 

They've actually tried clearing all the fault codes already as well...no luck.

 

My SA just called to say they talked to BMW and they're going to replace driver and passenger side seat modules and the TCU. Interesting...

Don't know if that's the problem but certainly wishing it'll solve the issue. The good news is that they're going to goodwill this.

 

Like you, I've noticed that the car wakes up when the key is close by, so I always make sure the key fob is not near the car. Also, my child proof lock out button for the windows would stay lite as well as the electronic gear shift and the start/stop button.

 

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.