[bch92]

Hi Guys! I have a 2006 325xi with 238,000 miles (runs like a champ) completely stock and no mods. It does have comfort access but the car is not recognizing the key. The key will not lock or unlock the car I have to use the manual insert and turn the lock. The car recognizes the key when it is put it the slot.

I am trying to figure out where to start to diagnose the problem. I have done some research and have checked the fuses. Where is the module on the car that registers the key fob or do we think the key is bad. Let me know what you all would do.

[ctuna]

Check the batterys both in the fob and in the car

The fob can work with a dead fob battery in it when inserted in the slot.

The battery is a common cr2032 I think, you can find it any drug store for
about 3 bucks. Or you can get 5 of them for 2 bucks of ebay.

Sounds like the Fob battery is dead.
Comfort Access Battery's are not rechargeable.

[Bavarian Tech]

Can you lock/unlock the doors using the central locking button in the car ? Generally speaking if that doesn't work. The fuse is blown and the one (if not two) door lock modules are faulty.

[bch92]

Key fob battery is brand new. The central locking button inside the car still works. Where is the receiver located inside the car?

[ctuna]

Did you recently install tinting
because certain types of tinting will block radio signals
but it should work inside the car anyway.
Are you sure the battery you installed was good and put in
the right orientation.
Do you have a voltmeter to check these things?

If the keyfob is brand new did you get it progammed for the car
with the comfort access option programmed?
Also if its brand new do you have any kind of warranty on it?


electical e90 pdf
http://www.google.com/url?sa=t&rct=j...,d.cGU&cad=rja
http://www.google.com/url?sa=t&rct=j...85464276,d.cGU
http://www.google.com/url?sa=t&rct=j...85464276,d.cGU

[bch92]

Key fob battery has power and is installed the right way. No tints or anything out of the ordinary. It's the original key that came with the car. So the car recognizes the key in the slot but not to use any buttons or CA features

[ctuna]

This is a classic indication of no power to the FOB
You can pull the battery out of the Fob and it will do the same
thing.
When the battery gets low in the fob there is usually an low bat indication
on the instrument cluster don't know what happens when its dead.
But I have a dead key just for getting in and starting the car that you insert
in slot and it works as you describe.
Why don't you have more than one Fob two are suppose to come with the car.

If you say the key fob is brand new that would mean it did not come with the
car . When you got it was it programmed for the car at BMW or somewhere else?
If you just ordered the Fob did they as you what specification the car had although
they should know with the VIN number.
Also they have a key reader at most BMW service centers why don't you take it
in and see if they can read it.

[bch92]

The key fob battery is brand new. Not the key fob itself, it is the origional. I bought the car second hand and only have one fob.

[ctuna]

So it has always been like this since you bought it?
Then I would complain to whoever you bought it from
and see if they will fix it.
The entire electrical system is described in those three PDF's
but I would verify the Fob any way I could first.

Did you check the main car battery as when it gets low IBS
system as described in the first PDF can start to turn stuff off that
is not necessary for the car to run.

[bch92]

Comfort access/key fob use to work fine. It just stopped working. The cars battery is fully charged so there should be no reason for the car to disable CA.

[ctuna]

I think you need code read and a verify of the key.
So you are going to have to take it in it looks like.
The comfort access module is located above the battery
If you look in the second link there is a explanation of how it
functions and where the modules are.

[VTECaddict]

Something is wrong with the fob or fob battery if even the buttons on it don't work. The remote buttons and CA are separate systems from each other and utilizes different signals and antennae. The remote buttons should still work even if CA doesn't if the fob is functional.

[gaverjam]

Hello,

I am seeing similar issues as OP.
This is the first post I have found with similar issues.
I have a 2006 325xi wagon, manual, iDrive, CA, etc.
I the only non original item I have installed is trailer hitch and hitch lighting wiring.

A little background on my issue:

Wednesday AM, things are all OK.
Wednesday night I drive out to go camping and everything is fine.
Show up at camping, shut off the car and huddle under the tailgate for 1-3 hours while setting up camp in the rain.
Thursday AM, trying to enter the car, CA does not work. I try the remote buttons, they do not work. I manually open driver door using hard key, and then unlock the rest of the doors with the center console button. CA starting does not work, but I was able to start with the key in the dash slot.
I do this the rest of the weekend running the car for 30-60 min each day to keep the car battery and phones charged up.
Monday morning, same deal. Drive home with no issues, just having to manually open door and key in slot at all the stops.
Tuesday AM heading to work, manually open the doors, key in slot, and nothing. Bricked...

I get the key with the slash through it on the gauge display and two bings.

Try my second key remote, same deal.
Change batteries on both key remotes, same deal.

Flashers work, interior lights work, center console lock button works.
Just nothing happens when key is inserted, it doesn't lock in like normal and cannot start the radio or the engine.

I put the battery on the trickle charger for a couple hours, tried again, same deal. I tried jumping the car, same deal.

I then checked the battery voltage, reading was 11.95, a little low.

Because I can't start up anything, I couldn't pull any OBD-II readings.

I don't know how this is related, but I can hear a constant clicking sound coming from the battery compartment area. When I pulled all the covers and padding away, it was coming from a white boxe attached to the wall with two out of the three bays occupied by computers(?). I disconnected the battery and the clicking stopped, reconnected the battery and it continued.

At this point being frustrated from looking at the issue all afternoon and making no headway, I decided I was going to totally disconnect the battery and try to fully drain the system. On the way to disconnecting the (-) terminal, I moved a bundle of wires to the side to get better access. The clicking stopped... I wiggled the bundle again, clicking did not return.... I tried starting the car with CA, but it would not. I put the key in the slot, it locked in like normal and started up. The dash lit up like a christmas tree but at least it started.

Errors: Key Error, AWD & DSC error, hill assist inactive.
Also, I noticed all the normally strong radio signals were super weak on the drive in today. Which matches the condition I saw on the drive home from camping. At the time I thought it was weird and maybe just the area we were in had weak signal.

I am no longer in daily driver emergency mode, but any insight or ideas on where to begin trouble shooting would be greatly appreciated.

[hellomyBMW]

I too, am having similar issues with my comfort access.
I just got my X6 and it does have comfort access for I have verified off BMWVIN decode and the door handles have the ridges on top.
The key fob unlock/lock/trunk button works perfectly fine but when I try to start the car with the key in my pocket, it does not work. It says that the key is not recognized or out of battery. So I have replaced the battery but comfort access still doesn't work.
I have made an arrangement at the local BMW to reprogram the fob key but they are asking $125 plus a few hours to test the vehicle.

Is this something I can re-program my self or do I need to code?

[E90335$]

I'm having the same exact problem you are bought the car second hand I only have one key I changed the battery on the remote and still nothing I have no idea what to do I have to manually open locks and trunk

[hellomyBMW]

Any advice anyone??
I've been spoiled by comfort access so it is very annoying to take the key out every time I need to open/start/stop the vehicle...

I honestly don't want to pay $125 to reprogram the fob... I rather use that money towards a nice set of DPs...

Please help!

[bch92]

Update on my issue. If I start the car with the fob in the slot. Then turn the car off and take the fob out. Then place my foot on the break and start without the fob in the slot the car starts and then key out of range warning pops up on iDrive.

[wildcatcrazy]

Originally Posted by bch92

Update on my issue. If I start the car with the fob in the slot. Then turn the car off and take the fob out. Then place my foot on the break and start without the fob in the slot the car starts and then key out of range warning pops up on iDrive.

Most (all?) BMWs will start immediately with FOB removed if done immediately after shutting down. That's some sort of safety feature they built in.

[socal619]

I had the same issue as previous post above and I had to take my car to get reprogrammed. ... my issue was when I bought my 335is, the salesman just gave me a key fob etc... and both my keys wasn't syncing with one and the other w/ the car so my local sa had to get po from az bmw to pay for it.. btw if u need get issue taken care. ...don't have your car in for service @ end of the wk cuz they don't reprogrammed on wkends.

[yoseikan]

I had this problem and the solution was to replace the diversity antenna amplifier, in my case located in the tailgate section (e91). Water ingress damages it, It is a common problem. You can try to get it out and clean it (worked for some) or to source an used one.

[bch92]

Excuse my ignorance but where is the diversity antenna amplifier in the sedan and is how can I test it for faults if even possible?