Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 7 Series / 8 Series > 7 Series - E65 / E66 (2002 - 2008)

7 Series - E65 / E66 (2002 - 2008)
Discussion pertaining to the flagship BMW here.

Reply
 
Thread Tools Display Modes
  #1  
Old 11-01-2009, 01:56 PM
Jon Barron Jon Barron is offline
Registered User
Location: Glasgow
 
Join Date: Nov 2009
Posts: 6
Mein Auto: 745i
Help! Battery Drain...

Something is draining my battery to the point where car will not start.

It has been in local garage for a week now and all they can point to is the module the covers the electric seats - apparently it should go to sleep as do all the modules at a pre-detrermined time i.e. approx 15mins.

This seems to stay on for about an hour!?!

Thus they have highlighted this as the potential issue!

Your thoughts??

They have suggested BMW as next step but will cost - can the fuse be pulled that covers this area?? to stop drain until i get the funds for repair??
Reply With Quote
Advertisement
  #2  
Old 11-01-2009, 02:22 PM
csmeance's Avatar
csmeance csmeance is online now
Officially Welcomed to the 'Fest
Location: Daytona Beach
 
Join Date: Dec 2007
Posts: 4,324
Mein Auto: 760Li
your best bet is to put a mulitmeter in a series with the battery (long enough wires so it can reach out of the trunk.

You will be able to see the draw on the battery, wait about 20 mins and you will see the draw when the car is off. Call your dealer and ask them for the spec. as to what it should be. Remove a fuse to a system of the car, and then repeat. If it doesn't drop, replace fuse and try another one. Repeat until you find the offending system.
Reply With Quote
  #3  
Old 11-01-2009, 02:40 PM
rustar's Avatar
rustar rustar is offline
Officially Welcomed to the 'Fest
Location: Chi
 
Join Date: Jun 2009
Posts: 768
Mein Auto: 745i
is your alternator good?
Reply With Quote
  #4  
Old 11-02-2009, 10:57 AM
west aussie 745 west aussie 745 is offline
bbj flt eng
Location: perth
 
Join Date: Jul 2009
Posts: 5
Send a message via Skype™ to west aussie 745
Mein Auto: 745i sapphire black
i had a similar problem. I work overseas and my 745i is parked for 7 weeks at a time with the battery switch in sleep mode without any problems of restarting but when i would park it overnight the battery would drain. My problem was the auto blower would star up at a pre determined time and drain the battery. The fan control module was replaced and all is now ok.Hopes this helps.
Reply With Quote
  #5  
Old 11-02-2009, 02:30 PM
Jon Barron Jon Barron is offline
Registered User
Location: Glasgow
 
Join Date: Nov 2009
Posts: 6
Mein Auto: 745i
Quote:
Originally Posted by rustar View Post
is your alternator good?
Alternator OK
Reply With Quote
  #6  
Old 11-02-2009, 02:33 PM
Jon Barron Jon Barron is offline
Registered User
Location: Glasgow
 
Join Date: Nov 2009
Posts: 6
Mein Auto: 745i
Quote:
Originally Posted by west aussie 745 View Post
i had a similar problem. I work overseas and my 745i is parked for 7 weeks at a time with the battery switch in sleep mode without any problems of restarting but when i would park it overnight the battery would drain. My problem was the auto blower would star up at a pre determined time and drain the battery. The fan control module was replaced and all is now ok.Hopes this helps.
Thanks...

Just waiting on garage to decide what they are doing, but they will no doubt try and wriggle out of fixing.

Computers = nightmare
Reply With Quote
  #7  
Old 11-02-2009, 07:40 PM
teejaylentz teejaylentz is offline
Officially Welcomed to the 'Fest
Location: Redmond, WA
 
Join Date: Sep 2008
Posts: 313
Mein Auto: 2002 745i
Quote:
Originally Posted by csmeance View Post
your best bet is to put a mulitmeter in a series with the battery (long enough wires so it can reach out of the trunk.

You will be able to see the draw on the battery, wait about 20 mins and you will see the draw when the car is off. Call your dealer and ask them for the spec. As to what it should be. Remove a fuse to a system of the car, and then repeat. If it doesn't drop, replace fuse and try another one. Repeat until you find the offending system.
+1

EDIT: I should have mentioned I did this way back when my battery was having issues... One tip I found is that you can trick the car into thinking the trunk is closed by clicking the latch/hook on the trunk locking mechanism (if I recall you just press the bottom of the locking mechanism until it clicks). You can then use your key to unlock the hook/lock later to bring it back to normal operation. Once the lock is engaged, the vehicle thinks that the trunk is closed and it will go to sleep (in 16 minutes I believe). Once in sleep mode you can play with fuses in the trunk and also monitor the AMPs on your amp meter as you do it. Of course, I'm sure certain fuses will cause the vehicle to come out of sleep mode if they are removed... so it will take some patience if it truly is a load happening only during sleep.

That said, it sounds as if they have already found the culprit (the seat module?) and that you could directly pull the fuse for that module for now until a dealer could look at it. The diagnostic tools that BMW has (DIS) will allow them to monitor voltage and amperage in real time and force the vehicle and/or specific modules into sleep mode to help diagnose the root cause.

EDIT #2: See attached a PDF with some detailed information I copy/pasted from the WDS and DIS a while back when I was diagnosing my own set of problems (which turned out to be battery related).
Attached Files
File Type: pdf Parasitic Load.pdf (545.1 KB, 493 views)

Last edited by teejaylentz; 11-02-2009 at 08:57 PM.
Reply With Quote
  #8  
Old 11-02-2009, 10:36 PM
Keif Keif is online now
Master Tinkerer
Location: Houston, TX
 
Join Date: Mar 2008
Posts: 2,201
Mein Auto: 2007 Alpina B7
.
__________________
 
Black 2007 Alpina B7
Tension strut bushings
 
White 2007 Alpina B7
Supercharger clutch/bearings, replaced exhaust valve/pulled head, sunroof seal, 6000K angel eyes
 
Black 2002 BMW 745Li (sold)
KW v3's, blue angel eyes, 8000K headlights & HID fogs, rebuilt alternator & mounting bracket gasket, sunroof seal, CCVs, plugs, sway bar bushings, timing & valve cover gaskets, valve stem seals, guibo joint, mechatronic sealing sleeve, trans fluid, sanded headlights...

Last edited by Keif; 11-02-2009 at 10:37 PM. Reason: BALEETED!!
Reply With Quote
  #9  
Old 11-04-2009, 05:14 PM
Jon Barron Jon Barron is offline
Registered User
Location: Glasgow
 
Join Date: Nov 2009
Posts: 6
Mein Auto: 745i
Quote:
Originally Posted by teejaylentz View Post
+1

EDIT: I should have mentioned I did this way back when my battery was having issues... One tip I found is that you can trick the car into thinking the trunk is closed by clicking the latch/hook on the trunk locking mechanism (if I recall you just press the bottom of the locking mechanism until it clicks). You can then use your key to unlock the hook/lock later to bring it back to normal operation. Once the lock is engaged, the vehicle thinks that the trunk is closed and it will go to sleep (in 16 minutes I believe). Once in sleep mode you can play with fuses in the trunk and also monitor the AMPs on your amp meter as you do it. Of course, I'm sure certain fuses will cause the vehicle to come out of sleep mode if they are removed... so it will take some patience if it truly is a load happening only during sleep.

That said, it sounds as if they have already found the culprit (the seat module?) and that you could directly pull the fuse for that module for now until a dealer could look at it. The diagnostic tools that BMW has (DIS) will allow them to monitor voltage and amperage in real time and force the vehicle and/or specific modules into sleep mode to help diagnose the root cause.

EDIT #2: See attached a PDF with some detailed information I copy/pasted from the WDS and DIS a while back when I was diagnosing my own set of problems (which turned out to be battery related).


Thanks for the detail - car still in garage - now in a bit of a dispute with them!>! pain in the rear, no wheels !!!
Reply With Quote
Reply

Bookmarks


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 7 Series / 8 Series > 7 Series - E65 / E66 (2002 - 2008)
Today's Posts Search
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On



Forum Jump


All times are GMT -7. The time now is 10:02 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms