E90Post
 


MINHS Auto Care Center
 
BMW 3-Series (E90 E92) Forum > BMW E90/E92/E93 3-series General Forums > General E90 Sedan / E91 Wagon / E92 Coupe / E93 Cabrio > Comfort Access Not Working + Low Battery??



Reply
 
Thread Tools Search this Thread
      03-03-2012, 03:56 PM   #1
chiefjefe
Registered
 
Drives: 07 335i coupe
Join Date: Mar 2012
Location: Oakland, CA

Posts: 2
iTrader: (0)

Comfort Access Not Working + Low Battery??

I have comfort access in my 07 335i. Problem is that it doesn't work when I try to unlock the car after the car has gone to sleep. I can press the unlock on the key fob and that will unlock the doors. Also, if the car is "awake" comfort access seems to work. Coming back to my car after work, however, comfort access never works.

Reading the forums, it sounds like my battery is draining and the car is going to sleep. I do get a low battery warning after a few minutes if the engine is off but the car is still on, so I am pretty sure that there's a battery problem of some kind.

I have a jb4, so not sure if that is causing the issue, although Terry @ BurgerTuning says it's not.

Curious if anyone knows what might be going on. About to take to the dealer, but have to remove the JB4, and it was a pain to install.
chiefjefe is offline  
0
Reply With Quote
      03-03-2012, 04:26 PM   #2
FirstBMWLA
Captain
 
FirstBMWLA's Avatar
 
Drives: 2007 335i Coupe
Join Date: Oct 2007
Location: Tucson,AZ

Posts: 770
iTrader: (10)

Car battery ever been replaced?
If not I'd say that. Your symptoms are exactly like mine were. If I had just opened car with FOB the CA would work.
If car had been sitting overnight etc it would not. When the battery starts going the car starts disabling unnecessary systems such as CA to conserve battery. So if car is "asleep" it will no longer
look for your keyfob being in proximity.

I had to replace battery and clear codes that put it into this power save mode using BT tool and also register new battery.

Last edited by FirstBMWLA; 03-03-2012 at 04:55 PM.
FirstBMWLA is offline  
0
Reply With Quote
      03-03-2012, 04:33 PM   #3
Thunder Dump
That tickles
 
Thunder Dump's Avatar
 
Drives: '09 328i E93 SGM/CR
Join Date: Jul 2009
Location: Western MA

Posts: 457
iTrader: (1)

Do you have RemoteKey+ installed also?
Thunder Dump is offline  
0
Reply With Quote
      03-03-2012, 04:42 PM   #4
335IAF
Enlisted Member
 
Drives: 2008 E90 335I
Join Date: Aug 2011
Location: Scott AFB, IL

Posts: 45
iTrader: (0)

Garage List
I'd try replacing the battery in the remote if you havent done so yet. $1 at walmart.
__________________

2008 E90 335I | 6MT | Sport | Premium | Cold Weather | CA | Logic7 | Black/Black
335IAF is offline   United_States
0
Reply With Quote
      03-04-2012, 03:44 AM   #5
chiefjefe
Registered
 
Drives: 07 335i coupe
Join Date: Mar 2012
Location: Oakland, CA

Posts: 2
iTrader: (0)

I tried replacing the fob battery once, didn't seem to work, but I'm going to try it again I think.

I don't have remotekey+ or any other mods other than the jb4.

The battery is probably 4 years old so maybe that is the issue? Guess it would make sense to try replacing that first. Car is a CPO, should I have the dealer do it or go to an indie shop?

Thanks for the advice btw!
chiefjefe is offline  
0
Reply With Quote
      03-04-2012, 09:12 AM   #6
John 070
Lieutenant General
 
Drives: 335i cpe
Join Date: Oct 2006
Location: ZSP/ZPP/ZCW

Posts: 11,409
iTrader: (0)

I replaced my battery at 5 yrs., asked for the old one back. Load tested it at home and it's fine. BMW battery lasts longer than 5 yrs imho....
John 070 is offline  
0
Reply With Quote
      03-04-2012, 11:26 AM   #7
ctuna
Brigadier General
 
Drives: 325xi 06 wagon MT
Join Date: Jan 2010
Location: Santa Cruz, Ca

Posts: 4,028
iTrader: (0)

The ibs can do strange things

http://www.bawarec.ru/manuals/3er/e9...3er-e90-12.pdf

Do the battery change yourself if you can you won't get gouged
as much.
ctuna is offline  
0
Reply With Quote
      03-04-2012, 01:29 PM   #8
Tom K.
Major General
 
Tom K.'s Avatar
 
Drives: '07 328iT, '13 Boxster
Join Date: Mar 2008
Location: Maryland

Posts: 5,361
iTrader: (0)

AS ctuna said, the IBS unit can do strange things.

After getting a low battery warning on my (unmodded) '07 E91 about a year ago, my dealer found no problems - until the tech tried to restart the car and had difficulty doing so. After throwing a couple of alternators at it (thank you, OEM warranty!), an intermittent fault with the IBS was found so it was replaced.

Everything worked fine for about 8 months, but I'm now having the same problem as the OP. About every 3rd day, the CA will not unlock the doors and the low battery warning appears when keeping the ignition on while parked. And once or twice, the missing key icon flashed and the car would not start without inserting the fob. The rest of the time CA works as it should. When the dealer recently checked the battery & charging system, everything was found to be OK, but every third day or so, the problem returns.

Since 2/3 of the time, CA functions normally and there are no warning icons, I'm reluctant to replace the battery. It seems as if some sensor is intermittently sending a spurious low battery message for some reason.

OP, unless I can get mine to the dealer while it is "acting up", I will be curious to hear how your situation works out.

Tom
Tom K. is offline   United_States
0
Reply With Quote
      03-21-2012, 08:30 PM   #9
odalis12
Enlisted Member
 
odalis12's Avatar
 
Drives: 2007 335xi
Join Date: Dec 2009
Location: nh

Posts: 46
iTrader: (0)

Sorry to high jacked this tread.I have the same issue and my car is in the dealer(been there for a week all ready). CA is not working ones the car goes to sleep(15 minutes after locking).They have replace the + battery cable and the fuse box, do to car shutting down while driving and having no power in the whole car in 2 occasion .They have also replace the car battery and remote control batteries and still CA not working after car goes to sleep.

They have replace the car handle and no luck.They have reprogram the car (?) and still not working. They are keeping it at the dealer because they are waiting for a BMW technician to come down and take a look at it on Monday.I had jb3 in car and took it out in Oct 2011 and all my other mods (back up camera). There is something big going on with my electrical system.

This is a list of my electrical issue since Oct 2011
1.nav screen replace no image
2.sat unit replace not working
3.radio dead wouldn't turn on replace
4.jb unit replace do to electrical acting up
5.L7 amp replace do to no sound
6.instrumental display replace do to speedo and tach not working
7.start stop switch replace do to not working
8.all door lock motor replace
9. all windows motor also replace

Sorry for the long reply, but the dealer knows me by name and said that they are going to put my name on one the parking space. I have 69k miles and it's a 2007 335xi.It's being in the dealer for 65 days since Oct 12 2011. Good thing is that I purchase there 7yrs/100k miles warranty and everything has been under warranty.I will keep you posted once they let me know.
__________________
2007 335xi Monaco Blue/ Sport Package/Navigation/ Ipod adapter/Premium Package/Cold Weather Package/Comfort Access/MSW 17" W/Michellin x-ice Winter Package/JB3/X-link Back up camera kit/k&N drop in filter
odalis12 is offline  
0
Reply With Quote
      05-17-2012, 09:26 AM   #10
philiphilip
New Member
 
philiphilip's Avatar
 
Drives: Graphite 2008 BMW 335i SP
Join Date: Jan 2012
Location: Springfield, VA

Posts: 27
iTrader: (0)

Tom K.,

I discovered the exact same problem you are having last night in my '08 335i. The CA has been working intermittently for some time, but i always thought i was doing it wrong. LOL

It sometimes locks but doesn't unlock after that, and the key battery discharged message appears on the dash. Yesterday it wouldn't start without the fob in the dash at all when i had it on just a few minutes before that.

Keep us updated as to what happens.
philiphilip is offline   United_States
0
Reply With Quote
      01-13-2014, 12:57 AM   #11
rogerdiaz
Lieutenant
 
Drives: 2011 335d
Join Date: Sep 2010
Location: Durham,NC

Posts: 526
iTrader: (2)

Quote:
Originally Posted by chiefjefe View Post
I have comfort access in my 07 335i. Problem is that it doesn't work when I try to unlock the car after the car has gone to sleep. I can press the unlock on the key fob and that will unlock the doors. Also, if the car is "awake" comfort access seems to work. Coming back to my car after work, however, comfort access never works.

Reading the forums, it sounds like my battery is draining and the car is going to sleep. I do get a low battery warning after a few minutes if the engine is off but the car is still on, so I am pretty sure that there's a battery problem of some kind.

I have a jb4, so not sure if that is causing the issue, although Terry @ BurgerTuning says it's not.

Curious if anyone knows what might be going on. About to take to the dealer, but have to remove the JB4, and it was a pain to install.
Any solution found? Replaced my key fob batteries and checked the car battery visually. Saw green dye.

one afternoon keyless entry and start just stopped working. All other buttons on fob work fine.

Last edited by rogerdiaz; 01-15-2014 at 10:23 AM.
rogerdiaz is offline   United_States
0
Reply With Quote
      04-20-2014, 03:11 AM   #12
leo67
New Member
 
Drives: 2012 BMW 335is
Join Date: Sep 2012
Location: Dallas, TX

Posts: 20
iTrader: (0)

Garage List
2012 BMW 335is  [0.00]
If the car thinks the car battery is low (whether it is or not ... A faulty ibs cable can report low voltage erroneously), comfort access is one of the first functions to be degraded in order to conserve battery. But once the car "wakes up" by unlocking with a fob for example comfort access functions are typically restored.

I had this problem but also bad intermittent lock and unlock when the car was fully "awake". Diversity antenna and tint replacement to ceramic seemed to fix it. This was under warranty and "goodwill" by BMW.
leo67 is offline   United_States
0
Reply With Quote
      04-20-2014, 03:44 PM   #13
leo67
New Member
 
Drives: 2012 BMW 335is
Join Date: Sep 2012
Location: Dallas, TX

Posts: 20
iTrader: (0)

Garage List
2012 BMW 335is  [0.00]
Troubleshooting comfort access problems is difficult. A variety of subsystems, signal paths, and handshaking are used. Faults are not always reported when the comfort access function is not working properly. And getting a BMW dealership to work on a problem that doesn't have a corresponding fault being reported can be difficult and may require BMWNA authorization. I'm speaking from my own personal experience.

If the problem is electromagnetic interfence (EMI) in nature, a fault will not always be reported. An example would be if the system is not recognizing your remote because RF signals sent or received are too low or degraded due to multipath interference (RF reflections which can can add or subtract or deteriorate a digital signal), environmental loss (e.g. tint), insufficient antenna gain at transmit and/or receive location . A certain design threshold must be exceeded for a signal to be processed correctly in any system which includes RF signals as a component. If the signal is inadequate, the system may not work properly or may not work consistently.

You could narrow the problem down to electromagnetic in nature if you observe different behavior say in the garage versus out in the open. I found that my comfort access would work reliably in my garage or an enclosed space but not in the open (say in a street or parking lot). I also found "dead zones" where if I held out the remote in one spot comfort access worked but in another spot it would not. These are indications of EMI or signal loss.

I would always suggest the first, easiest thing to try as a fix if you're experiencing comfort access problems is simply to swap out battery in your remote with a new one. Beyond that, things can get much more complex to diagnose and fix.
leo67 is offline   United_States
0
Reply With Quote
      06-22-2014, 08:12 PM   #14
rogerdiaz
Lieutenant
 
Drives: 2011 335d
Join Date: Sep 2010
Location: Durham,NC

Posts: 526
iTrader: (2)

Is there a comfort access "fuse" to check? What number?
rogerdiaz is offline   United_States
0
Reply With Quote
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 Off
Forum Jump


All times are GMT -5. The time now is 01:39 AM.




e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST