2001 e39 alarm problem

[bmwhiteman]

My key randomly stopped unlocking my doors and opening my trunk. Alarm works fine if I lock it with the key in the door. It beeps and locks all the doors fine when I do that. I tried reprogramming it with several different methods I found in the search and even tried programming my friends 330ci key to mine. It stopped working on his but still wouldn't do anything on mine. It reprogrammed to his car first try. I checked all the fuses I could think of but they are all good. Seems to be a problem with something on the car. Any ideas?
Thanks

Actually got my friends key programmed to my car. Im thinking battery so I cracked my key open and tested voltage. 3.43v and 3.2v when a button is pressed. I tested all the buttons. Maybe my transponder just gave out


So I peeled back the sticker while I was checking out the circuit board and this tiny chip fell off. its stuck to the sticker now for safe keeping and was directly below the battery. any idea what it is?

[mattmartindrift]

that's the transponder that your EWS needs to see to allow the car to start.


have you tried re-initializing the key?

[Qsilver7]

The EEPROM (transponder chip) is only for the EWS feature of the key...it has NOTHING to do with FBZV or DWA (keyless entry & alarm siren system).

Did you check your fuel filler flap door to see if it locks when you lock the car? Stick the key into the door lock cylinder & lock the car...then walk around to the fuel filler door to see if you can open it. If you can open it...then you need to RECHECK the central locking fuse (in the trunk) to see if it is blown. Did you check the fuses in the trunk previously?

Even if the fuse in the trunk isn't blown...if the fuel filler door actuator is not working (but it's electrical harness is still connected)...it is sending a fault to the central locking system (FZV)....which is preventing the keyless entry (FBZV) from working. The keyless entry system will NOT work if the central locking system has a fault.

The latter two features (FBZV & DWA) only transmits (one way) a radio frequency to the receiver in the C-Pillar...which then sends that data on to the GM to lock/unlock the car....and to the alarm siren to arm/disarm.

The transponder chip (transponder means that it transmits as well as receives data) is used by the EWS feature of the key. EWS sends and receives data to all it's components where they all must communicate that they share the same ISN (individual serial number).

The transponder (on the new style key) is one of the chips soldered to the IC board...see the pic below for its' location...I'm not sure what it is that you pictured...but it's not the EWS transponder...check to see if there is a missing component on the IC board where leads are running to an area with nothing there:

(transponder chip...soldered to IC board inside new style key)


(transponder chip inside the old style key...it is moveable and sits off to the side inside the key...just like it is in all the other key styles)


(all the other key types (valet/spare/wallet/illuminated) have the same type of transponder chip as the old style remote key)

[testdood]

That is a surface mount capacitor or resistor. You should solder it back on the board and see if it works. If you have never soldered such a small surface mount component I would recommend finding someone who has the correct type of soldering iron and some experience to help.

[bmwhiteman]

That is a surface mount capacitor or resistor. You should solder it back on the board and see if it works. If you have never soldered such a small surface mount component I would recommend finding someone who has the correct type of soldering iron and some experience to help.

Ya i tried resoldering it but i couldnt get an impedance reading through it. I wish I knew exactly what it was for. I know its my key because my car programmed to my friends 330ci key and my 525i key first try. My gas door lock has never worked so i know thats not the issue. Crevier BMW quoted me $220 for a new key. might not be a bad idea cause I only have 1 key right now. This one could just be a backup

[testdood]

It has been awhile since I have worked in electronics, but from the look of it that part is a capacitor or possibly a fuse. See if you can see any markings on it with a magnifying glass. If you can, search for the part at the DigiKey website. If you can figure out what it is you should be able to order 1-5 parts for a couple of dollars.
If you are soldering this yourself make sure you set the temperature on your soldering iron relatively low, maybe 720F.

By the way, if you have a multi-meter it will most likely have capacitance testing capabilities. Google 'test a capacitor' to see how to do it. If it is just a fuse all you need to do is put a voltage across it to see if it has been blown. If you dont have a multimeter, here is a cheap one that will work just fine:
Amazon

Good luck figuring out what the part is, even if this just becomes a back-up key. I feel your pain with the dealership key prices. I think I paid around $250 for mine last year.

[Qsilver7]

... My gas door lock has never worked so i know thats not the issue...

...unless your fuel filler door is unplugged and that's the reason it has never worked...you can spend money on new keys and paying for diagnostic work until the world comes to an end...but your keyless entry system isn't going to work if that fuel filler door actuator is plugged in and not working. As long as it is sending a signal that it is malfunctioning...I'll say it for the last time...a fault in the central locking system is NOT going to allow the keyless entry system to work.

FZV(the central locking system) has to be working without any faults in order for the keyless entry (FBZV) to work. If there's a blown fuse or non working actuator registering a fault in the central locking system...FBZV isn't going to work.

If it IS a faulty actuator...if you unplug it...(and make sure the fuse is good)...then it is no longer registering a fault...and you can program the FBZV to lock/unlock & arm/disarm.

[bmwhiteman]

...unless your fuel filler door is unplugged and that's the reason it has never worked...you can spend money on new keys and paying for diagnostic work until the world comes to an end...but your keyless entry system isn't going to work if that fuel filler door actuator is plugged in and not working. As long as it is sending a signal that it is malfunctioning...I'll say it for the last time...a fault in the central locking system is NOT going to allow the keyless entry system to work.

FZV(the central locking system) has to be working without any faults in order for the keyless entry (FBZV) to work. If there's a blown fuse or non working actuator registering a fault in the central locking system...FBZV isn't going to work.

If it IS a faulty actuator...if you unplug it...(and make sure the fuse is good)...then it is no longer registering a fault...and you can program the FBZV to lock/unlock & arm/disarm.

Well seeing as it has never worked, the fuses are fine, and it is plugged in, that is not the problem. My alarm has gone off plenty of times and has worked perfectly up to this point. Seeing as any other BMW key can be programmed to my car first try, my key is what is bad. This has nothing to do with my filler door

It has been awhile since I have worked in electronics, but from the look of it that part is a capacitor or possibly a fuse. See if you can see any markings on it with a magnifying glass. If you can, search for the part at the DigiKey website. If you can figure out what it is you should be able to order 1-5 parts for a couple of dollars.
If you are soldering this yourself make sure you set the temperature on your soldering iron relatively low, maybe 720F.

By the way, if you have a multi-meter it will most likely have capacitance testing capabilities. Google 'test a capacitor' to see how to do it. If it is just a fuse all you need to do is put a voltage across it to see if it has been blown. If you dont have a multimeter, here is a cheap one that will work just fine:
Amazon

Good luck figuring out what the part is, even if this just becomes a back-up key. I feel your pain with the dealership key prices. I think I paid around $250 for mine last year.

Ya there are no markings on it. I tried both tests and I have a cert in electrical metering so I know I did it right. Whatever it is, it's blown. I already called around and beverly hills BMW can get me a new key for $178 out the door. I think I'm gonna go for it since I currently have no spare

[bmwhiteman]

::::UPDATE::::
Got the new key from the Beverly Hills dealer, Problem solved, all buttons work, programmed first try