Rear defogger issues - BMW 3-Series (E90 E92) Forum

Quinten · 02-14-2011, 11:18 AM

Just wondering if someone has had this issue, and maybe knows where I can start looking before I need to bring it in for help.
My '06 e90 rear defogger is not working. It starting fall of last year, working intermittently. I could turn it off and on a couple of times then it would work. The last couple of months it doesn't work at all. The light on the switch comes on when pushed, and the fuse checked out OK.
Anyone have any clues as to where to look?
Thanks.
Q.

csupernova · 02-16-2011, 11:28 PM

last time i had the exact same problem. I changed to a new car battery and problem solved.

Quinten · 02-17-2011, 06:16 AM

Thanks for the info. Maybe it needs some sort of "reset"/power down sort of thing?

john_e90bimmer · 02-18-2011, 01:03 AM

You need a new battery, see my post here I had the same problem http://www.e90post.com/forums/showthread.php?t=482754

volkswackin · 02-19-2011, 08:56 PM

yep-battery issue likely or IBS problem. Both will cause consumer cutoff issues and thus turn off the rear defroster. Check the battery and scan for any IBS

Quinten · 02-22-2011, 06:16 AM

John, thanks. I read your issues regarding similar symptons. Did your symptons go away once the battery was changed? (I am assuming they did)The other similarity is my heating blower will continuously change speeds from like low to med. to med high, then to low, then back up. It just doesn't stay steady unless on defrost mode. So this might also be a sympton of the battery?
One question, and I will search, but just in case, what is IBS?
Thanks guys.
Q.

timmahh · 02-22-2011, 09:33 AM

Quote:

Originally Posted by Quinten

John, thanks. I read your issues regarding similar symptons. Did your symptons go away once the battery was changed? (I am assuming they did)The other similarity is my heating blower will continuously change speeds from like low to med. to med high, then to low, then back up. It just doesn't stay steady unless on defrost mode. So this might also be a sympton of the battery?
One question, and I will search, but just in case, what is IBS?
Thanks guys.
Q.

IBS = Intelligent Battery Sensor (I believe)

The blower speed may also be a result of a bad or failing battery, but that's also a symptom of a bad final stage resistor. It sounds like a battery is needed no matter what; start with that - then see if all of your issues are resolved.

02-14-2011, 11:18 AM	#1
Quinten Private Drives: Silver 2006 E90 Join Date: Nov 2008 Location: Enumclaw, WA. Posts: 55 iTrader: (0)	Rear defogger issues Just wondering if someone has had this issue, and maybe knows where I can start looking before I need to bring it in for help. My '06 e90 rear defogger is not working. It starting fall of last year, working intermittently. I could turn it off and on a couple of times then it would work. The last couple of months it doesn't work at all. The light on the switch comes on when pushed, and the fuse checked out OK. Anyone have any clues as to where to look? Thanks. Q.
	Tweet

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

02-16-2011, 11:28 PM	#2
csupernova Lieutenant Drives: E90 330i Join Date: Sep 2007 Location: NYC Posts: 596 iTrader: (6)	last time i had the exact same problem. I changed to a new car battery and problem solved.

02-17-2011, 06:16 AM	#3
Quinten Private Drives: Silver 2006 E90 Join Date: Nov 2008 Location: Enumclaw, WA. Posts: 55 iTrader: (0)	Thanks for the info. Maybe it needs some sort of "reset"/power down sort of thing?

02-18-2011, 01:03 AM	#4
john_e90bimmer Enlisted Member Drives: Silver Join Date: Dec 2009 Location: Illinois Posts: 38 iTrader: (0)	You need a new battery, see my post here I had the same problem http://www.e90post.com/forums/showthread.php?t=482754

02-19-2011, 08:56 PM	#5
volkswackin Lieutenant Colonel Drives: too broke for a BMW Join Date: Jan 2008 Location: i get around.. Posts: 1,827 iTrader: (1)	yep-battery issue likely or IBS problem. Both will cause consumer cutoff issues and thus turn off the rear defroster. Check the battery and scan for any IBS

02-22-2011, 06:16 AM	#6
Quinten Private Drives: Silver 2006 E90 Join Date: Nov 2008 Location: Enumclaw, WA. Posts: 55 iTrader: (0)	John, thanks. I read your issues regarding similar symptons. Did your symptons go away once the battery was changed? (I am assuming they did)The other similarity is my heating blower will continuously change speeds from like low to med. to med high, then to low, then back up. It just doesn't stay steady unless on defrost mode. So this might also be a sympton of the battery? One question, and I will search, but just in case, what is IBS? Thanks guys. Q.