Increased batt discharge

[Rookie2]

Hi all,

Need some advice. Am driving a 2010 E90 M3.

Had the message "increased battery discharge" couple of times. But few days ago tried starting the engine (after not driving for 2days) and couldnt. Basically batt was flat. Jump started the car and brought to workshop.

Scanned for fault codes and one appeared 'front door contacts'. Tested the doors using the workshop's OBD tool and all doors were ok. Batt and alternator were checked and everythings fine.

Before the increased batt discharge and when engine's running the comfort access functions were working fine (ie unlocking and locking and starting engine).

Workshop disabled the comfort access module (right side of trunk) and I monitored for few days. No messages at all. Brought the car back to have another scan.....no faults whatsoever except the CA Module(since it was disabled).

Workshop cant ascertain for sure if its the Comfort Access module or which door handle that is faulty.

Wondering if anyone has had the same issue? Should i replace the CA module, door handles, or even the CAS Module (in this particular order?)? Replacing these items is very costly and I cant even pinpoint for sure if any of those is the culprit.

Please help.

Cheers.

[E92Brembo]

Had similar issue a while back and researched it extensively. My issue ended up being the EDC module in the trunk.for your issue, I'd enable the CA module and unplug the handles one at a time for a few days to isolate which one may be the culprit. If the batt discharge reoccurs with them all unplugged, it's more than likely your CA module. Hope this helps

[beats]

I had that error when my battery was on its last legs. It wasn't driven enough (by the previous owner )

[Bavarian Beast]

I just had my EDC unit go out and was a monster battery killer. I would first check the battery to see if it is old and can hold a charge when not in the car or with a voltmeter. If it isn't the battery you can also unhook your EDC module and see if that fixes it. You can still drive it, but the stiffness is on sport mode so a bit tight for all the time. I also agree with E92Brembo to trouble shoot the handles. Good luck.

[BPMSport]

Check to see if the start button stays lit 20 minutes after locking the vehicle. If it is, something is causing the car not to fall asleep, and usually it's the edc module.

[Bavarian Beast]

Resolution yet?

[BombaE90]

Change the battery and make sure it's properly coded. I changed the battery to a Sears replacement, had it coded and the increased battery discharge continued.

I fried the EDC unit when I jump-started the car, and went on a wild goose chase trying to figure out the problem.

I finally bit the bullet and bought an OEM battery and had the dealer code it. Everything went away and has been fine since.

I'd just spend the money on an OEM battery and coding by someone that really knows what they're doing. That's my advice after chasing this problem for 4-5 months.

[Magnetic Fusion]

I have the same problem with the Increased Battery Discharge, but, I ony get it at temps under 40 degrees or under 30 degrees. Only during winter this happens. Happens to my buddies 335 also. We haven't found solutions yet but I do have an aftermarket battery in mine. Never coded it to the car (don't know why you need to code a battery???) The car runs fine and doesn't generate codes during non cold days. I just write it off as cold weather affecting the battery drain, like it affects tire pressure. I can't see paying $300 for a battery because it has the letters BMW on it.

[M3LISSA]

I had this problem for months. The dealer replaced the battery, happened again right away, one day the car died and locked me out. I had the keyhole cover on from IND and couldn't get it. I called Bmw assist and they sent pop a lock and those guys got into my car in less than 60 seconds. Anyway, they charged my car battery and told me it's fine, not showing anything. I hesitated but said okay. Before I left to go pick it up they called me back, the car locked them out! They had trunk open and were able to get in! So what they found in the end thank god it was there was my circuit panel had fried. Hardly happens but it did. They replaced it under warranty and I haven't had a problem since...