Service department is having trouble diagnosing Comfort Access Problem

SpacegrayMe90 · 03-30-2015, 01:54 PM

I dropped my car off at the service department on 03/21/2015, to have my passenger side comfort access door handle replaced. They kept the car for about a week. Finally, they call me and tell me I'm all set and to come get your car. When I get there the passenger side comfort access still does not function.

They replaced the CAS Module along with the door handle. The technician seemed perplexed as to what's going on when questioned about it. He said no fault codes are shown.

Any ideas what might be going on from your past experience with the comfort access door failing?

I'm going into my second week without the M3, just want to get past this already.

roastbeef · 03-30-2015, 02:59 PM

I had something similar happen, but it was a key that was faulty. They replaced both keys and the control module for the comfort access system. As far as I know, no handles were replaced. It does seem like it is a system they have a difficult time diagnosing.

Jesus E90 M3 · 03-30-2015, 04:47 PM

This might sound stupid, had same problem and i fixed it by changing the car battery... it was old and about to die, so system shuts down to save energy.

kscarrol · 03-30-2015, 05:05 PM

Could be but I would think a battery so weak that various systems were being shut down to conserve power would also throw some codes related to the battery...

BzsBimmer · 03-30-2015, 07:37 PM

I'm perplexed how the dealer can tell you that the car is ready when it isn't.
Meh... these things happen. Something was working when the tech tried it out.

I'd suggest to them a new battery (bring one down) or to try a new key fob. I'm sure when you mention that you saw it on a forum, the tech and SA may just

Chicken Little · 03-30-2015, 09:13 PM

Quote:

Originally Posted by Jesus E90 M3

This might sound stupid, had same problem and i fixed it by changing the car battery... it was old and about to die, so system shuts down to save energy.

+1 ^ Had this happen to one of my previous cars and once the battery was replaced the problem I was having went away.

BzsBimmer · 03-31-2015, 09:35 PM

Aaannndddd....

iansanderson · 04-04-2015, 10:56 PM

It could be a wiring issue, but I would guess the key is to blame. Just went through a comfort access diag for my trunk not opening. They replaced the trunk access antenna (behind the rear bumper) and the CA module. Also, brand new Varta key fob battery from the dealership. No difference. For your passenger door issue, the exterior door handle houses all of the CA electronics and antenna for that zone. Aside from wiring, or a cell phone being permanently lodged in your door and transmitting, I don't see what else could be to blame. I would say a new key is your next stop.

I am going to replace mine if it bothers me enough with the hope it fixes it, but I just deal with it for now.

SpacegrayMe90 · 04-10-2015, 11:31 AM

Update: My issue was resolved. The problem was a wiring malfunction that sends the signal to the comfort access antenna. I will try to post the specifics of my SA write up once I get a chance. It may help you guys having the same recurring issues. Took my car being at the dealership damn near two weeks for a full resolve. Nonetheless it feels good to able to open and close my passenger door without the fob after a year of it not working.

bdaddylo · 04-11-2015, 11:11 PM

Quote:

Originally Posted by SpacegrayMe90

Update: My issue was resolved. The problem was a wiring malfunction that sends the signal to the comfort access antenna. I will try to post the specifics of my SA write up once I get a chance. It may help you guys having the same recurring issues. Took my car being at the dealership damn near two weeks for a full resolve. Nonetheless it feels good to able to open and close my passenger door without the fob after a year of it not working.

Glad to hear that your problem was resolved. One thing I hate with the design is that CA doesn't work on the rear doors.

nthretourNAFTW · 04-11-2015, 11:28 PM

Quote:

Originally Posted by SpacegrayMe90

I dropped my car off at the service department on 03/21/2015, to have my passenger side comfort access door handle replaced. They kept the car for about a week. Finally, they call me and tell me I'm all set and to come get your car. When I get there the passenger side comfort access still does not function.

They replaced the CAS Module along with the door handle. The technician seemed perplexed as to what's going on when questioned about it. He said no fault codes are shown.

Any ideas what might be going on from your past experience with the comfort access door failing?

I'm going into my second week without the M3, just want to get past this already.

comfort access failing could be due to bad electronics in the radio. Like a power amplifier that lost performance prematurely.

BzsBimmer · 04-12-2015, 12:46 AM

Quote:

Originally Posted by bdaddylo

Glad to hear that your problem was resolved. One thing I hate with the design is that CA doesn't work on the rear doors.

I agree. I think it does on the X5

03-30-2015, 01:54 PM	#1
SpacegrayMe90 First Lieutenant 133 Rep 372 Posts Drives: 2010 e90M3 Join Date: Apr 2012 Location: NYC iTrader: (0)	Service department is having trouble diagnosing Comfort Access Problem I dropped my car off at the service department on 03/21/2015, to have my passenger side comfort access door handle replaced. They kept the car for about a week. Finally, they call me and tell me I'm all set and to come get your car. When I get there the passenger side comfort access still does not function. They replaced the CAS Module along with the door handle. The technician seemed perplexed as to what's going on when questioned about it. He said no fault codes are shown. Any ideas what might be going on from your past experience with the comfort access door failing? I'm going into my second week without the M3, just want to get past this already. Last edited by SpacegrayMe90; 03-30-2015 at 03:02 PM..
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03-30-2015, 02:59 PM	#2
roastbeef Lieutenant General 11586 Rep 12,728 Posts Drives: E92 M3 Join Date: Nov 2010 Location: Orange County, CA iTrader: (4)	I had something similar happen, but it was a key that was faulty. They replaced both keys and the control module for the comfort access system. As far as I know, no handles were replaced. It does seem like it is a system they have a difficult time diagnosing. __________________ Instagram; @roastbeefmike
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03-30-2015, 04:47 PM	#3
Jesus E90 M3 Private First Class 41 Rep 170 Posts Drives: E90 M3 Join Date: Mar 2015 Location: Jordan Middle East iTrader: (1)	This might sound stupid, had same problem and i fixed it by changing the car battery... it was old and about to die, so system shuts down to save energy.
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03-30-2015, 05:05 PM	#4
kscarrol Brigadier General 8912 Rep 4,107 Posts Drives: 2021 X3 M40i, 1974 2002 Tii Join Date: Jun 2010 Location: Greenville, SC iTrader: (0)	Could be but I would think a battery so weak that various systems were being shut down to conserve power would also throw some codes related to the battery... __________________ 2021 X3 M40i 1974 2002tii, Inka, 5 sp manual BMWCCA # 327475
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03-30-2015, 07:37 PM	#5
BzsBimmer Major General 3274 Rep 6,723 Posts Drives: '23 G80 FO M3, M3 & MY Tezzy's Join Date: Mar 2006 Location: Nor. Cal iTrader: (32)	I'm perplexed how the dealer can tell you that the car is ready when it isn't. Meh... these things happen. Something was working when the tech tried it out. I'd suggest to them a new battery (bring one down) or to try a new key fob. I'm sure when you mention that you saw it on a forum, the tech and SA may just
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03-31-2015, 09:35 PM	#7
BzsBimmer Major General 3274 Rep 6,723 Posts Drives: '23 G80 FO M3, M3 & MY Tezzy's Join Date: Mar 2006 Location: Nor. Cal iTrader: (32)	Aaannndddd....
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04-04-2015, 10:56 PM	#8
iansanderson Enlisted Member 2 Rep 45 Posts Drives: 2013 X5M Join Date: Apr 2012 Location: North Canton, Ohio iTrader: (0)	It could be a wiring issue, but I would guess the key is to blame. Just went through a comfort access diag for my trunk not opening. They replaced the trunk access antenna (behind the rear bumper) and the CA module. Also, brand new Varta key fob battery from the dealership. No difference. For your passenger door issue, the exterior door handle houses all of the CA electronics and antenna for that zone. Aside from wiring, or a cell phone being permanently lodged in your door and transmitting, I don't see what else could be to blame. I would say a new key is your next stop. I am going to replace mine if it bothers me enough with the hope it fixes it, but I just deal with it for now.
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04-10-2015, 11:31 AM	#9
SpacegrayMe90 First Lieutenant 133 Rep 372 Posts Drives: 2010 e90M3 Join Date: Apr 2012 Location: NYC iTrader: (0)	Update: My issue was resolved. The problem was a wiring malfunction that sends the signal to the comfort access antenna. I will try to post the specifics of my SA write up once I get a chance. It may help you guys having the same recurring issues. Took my car being at the dealership damn near two weeks for a full resolve. Nonetheless it feels good to able to open and close my passenger door without the fob after a year of it not working.
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