Key Fob Issue

[CleanIsFast]

Okay so ever since I purchased the vehicle, neither one of the key fobs actually work in unlocking/locking the vehicle via the buttons. Everything has to be manually done; inserting key into door lock and to start the vehicle as well. It's not a HUGE deal to me but it does get annoying from time to time when I forget to lock the vehicle when I walk away and have to go back.

So, before I start to throw money at the issue I started to do some research. Came across numerous threads spanning different chassis models. Some of the troubleshoot items are cheap and others are expensive. I honestly don't think it's a battery issue because from what I read those batteries should last a very long time. I won't get into a debate about it because it'll turn into an oil thread.

Initially I sent one key fob off to California for repair. (www.bmwgm5.com/bmwgm5/kr.htm) Reason I did this was because when I would unlock the car (manually), open the door, the interior lights would come on. IF the interior lights didn't come on, I believe this would be a general module issue. After 2 weeks (which is stupid long), I received the key fob back. If the battery was bad, he would've replaced it, this was not the case. Excited, I followed the directions to 'sync' the key to the vehicle:

1. Working from within the vehicle and with the doors shut
2. Turn ignition to position 1 and back to off within 5 seconds.
3. Remove the key from ignition and press and hold the unlock button for 15 seconds during this time press the key lock button 3 times within 5 seconds.
4. Release both buttons.
5. Doors will lock and unlock to show correct programming has occurred.

Step 5 never occured, the sync didn't seem to work. Continuing to research some people said to keep the key in position 2, then hold the unlock button, take the key out, press lock 3 times. That did NOT work either.


So at this point I am back at square one, still troubleshooting. My next step is to check the fuses (which I probably should've checked first). I believe I need to check fuse(s) 20, 24, 60 for the central locking system. Please correc me if I am wrong. I am really hoping it's just a fuse and not the next step.


Next step would be to look at the FZV Antenna
- https://www.bmwgm5.com/FZV_Antenna_Amp.htm
- Location: https://www.bmwgm5.com/Images/FZV/FZV_X5_Location.jpg
- Module: https://www.bmwgm5.com/Images/FZV/FZV_X5_Module.jpg


After that I am not really sure what to check? The actual GM3 module? It's located behind the glove box, removal instructions here:
https://www.bmwgm5.com/GM3_X5_Removal.htm
Information: https://www.bmwgm5.com/

Possibly just biting the bullet and buying a set of new key fobs? BMW Fairfax has them for $140, but I am sure they charge you for programming the keys.


Here is some info from QSilver7:

Originally Posted by QSilver7

Against better judgement (since the original post date was Aug/2009....6+ years ago)...there was no mention if the OP ever tried simply re-initializing their remote key since it hadn't been used for a long time. For posterity sake...the instructions on how to reinitialize the FZV/DWA features of the remote keys (old & new style) are listed below.

Also...there was no distinction between EWS/FZV/DWA...so the 3 features of the remote keys was glossed over as if there's only one function/one system...when there's actually 3 systems involved with the remote keys:

• EWS - immobilizing system (no start if key doesn't match EWS-CM & DME/ECU)
• FZV - central locking system
• DWA - anti-theft alarm siren system

EWS is self powered (thru induction) and doesn't require the battery inside the remote key. Only the FZV & DWA features of the key require the battery inside to transmit the RF signal to the car.

The no start issue after the OP opened the key to replace the battery...probably was due to the OP damaging the circuit board when they broke the key open. If not careful...one can cut resisters & capacitors off the IC board...are cut/scratch the traces on on the board or antenna...thus rendering the key non-workable.

Not just any locksmith can "program" or initialize the EWS portion of the remote keys. If you and the locksmith are unfamiliar with EWS and how it works/performs...then more than likely you're in for a big disappointment.

If the "locksmith" DOES understand BMW's EWS system...and you don't...then you've struck gold and may end up saving yourself a lot of money. They will need an AK90 set-up to retrieve the ISN (individual serial number) data and key codes that have been burned into the EWS-CM...then have the ability to write that data to a blank EEPROM (transponder chip) that has to be somewhere inside the new remote key. If not...the key will not be able to start the car on its own...even if they cut the blade correctly.

Any BMW remote key that was mfg'd for the e38/e39/e46/e52/e53...are all compatible in regards to FZV & DWA. Any of these keys (old style or new style) can be programmed to lock/unlock & arm/disarm any of the aforementioned BMW models. The caveat is...the new style keys are charged while in the ignition...so if you don't have a way of charging the new style key...then the battery dies along with your ability to use it as a remote/keyless entry tool.

Hope these few comments helps clarify some of the many misconceptions owners have about their remote keys. The topic is oft discussed (to death)...but continues to bewilder/befuddle/bewitch owners.