E46 M3 key fob issues

[stadtler]

Hi all,
I'm having issues with my key fob.
Recently fob #1 stopped working - I assumed battery finally died (it is 19 years old after all).
Fob 2 has never worked in the 13 years I've owned the car - I've always assumed the battery was dead and never had a chance to recharge as the key wasn't used.

I went about replacing both batteries; easy peasy. Then I went about the fob reprogramming. Turn the ignition on/off, hold down the door unlock button, press the lock button 3 times - but I don't get the door lock/unlock when I complete those steps. I've tried a bunch of times, including some of the variants like turning the ignition to the first pos and off 5 times quickly. Still no luck in reprogramming either fob.

Any idea what i might be missing here? One oddity, my fob 1, the one I've always used, does lock the doors with no problem. I just can't unlock or pop the trunk. Fob 2 is still totally useless. Is there another part in the remote lock/unlock system that can fail?

Thanks for any advice you can offer!

[MarcoZandrini]

Fobs have 2 separate electronic circuits. The remote lock/unlock circuit is powered by the battery. The other circuit, the anti-theft + engine start circuit, is powered by the ring antenna that surrounds the ignition lock.

It sounds like fob #2 is dead, as if it spent a day in salt water dead! I’d buy a new key at www.bmwminimarts store.com. I think that dealer in Cincinnati has the best price on a fob. But check around anyway.

Are you sure you properly replaced the battery in fob #1? It sounds like the remote lock/unlock circuit isn’t working. As for the inability to open the trunk, that sounds like the trunk unlock switch is bad. Can you unlock the trunk using the button under the dash? If you can then the fob is the problem.

[jclausen]

As the guy says who rebuilds these keys says more times than not the battery is just fine, when I took apart mine and test the battery they were all good

[stadtler]

Just to close the door on this thread in case anyone finds it years from now - The issue was the key fob. I ordered up one of the $10 fobs from ebay. It synced right up via the standard process and works to lock and unlock the car.
Thanks everyone for your advice.

[Mataa]

Just to close the door on this thread in case anyone finds it years from now - The issue was the key fob. I ordered up one of the $10 fobs from ebay. It synced right up via the standard process and works to lock and unlock the car.
Thanks everyone for your advice.

Good for you. Coz my problem is the locking which doesn't work. The unlocking and trunk work perfectly. And even if I have just bought a new key and an AK90 on ebay, I cannot program the new key to lock coz the locking button on the original key doesn't work. I need to find a smiths person to cut the key first then I can program it for remote use.