Audi sure can make things WAY overly complicated for everyone, including themselves.

Does anyone here know anything about the compatibility of keyfob/remotes on the A4, specifically the 05-08 remotes.

Firstly, I'm not talking about the immobilizer. I've resigned to the fact that the dealer has to work Audi magic there.

I'm talking about buying used keyfobs that match yours, and trying to program them for the lock/unlock buttons.

I bought a car with 1 working remote. I have 3 other remotes. They all share the same 315MHz freq, and part number. They share the same FCC ID #. I can't decipher the other numbers, likely batch code, and or other part numbers.

I was able to program 1 of the 4 remotes for lock/unlock. The other 2, I cannot get to work. This is using the unlock button, turn ign on with good key, off, key out, press unlock on new fob method. All the batteries light up the red LED on the remotes. I tried about 10x on each remote before giving up.

Do I have the right method(listed in the user manual)?
What is the magical #(s) that I need to look for on the side of the remote?

Any other info you can share?

Thanks,

Thomas

I'm pretty sure for the A4, there are a total of 4 keys that can be associated with the car. Whether that means 2 remotes, 1 valet and 1 master key, or 4 remotes and no other keys I don't know. And that is my understanding for immobilizer.
What you're bringing up crossed my mind as far as whether using this method of associating remotes(not immobilizer) can be done for more than 1 additional remote at any 1 time/instance. Sounds weird to limit, but we're talking about VAG here.

Furthermore, in my case, I have only 1 working key to work in the tumblers. This means, I need to put my good key in the ignition, and go through the procedure with the other key in my hand(since my other 3 keys don't have a working blade that can turn the locks/tumblers yet). As this seems to work fine, it is not quite what Audi intended for this procedure. They list this as a 'remote reset' procedure(page 59), in the event that the remote doesn't unlock the car due to some battery change gone bad, or other reason.

Any help, or other links and knowledge on this would be real useful. There is so much misinformation on the web about this stuff.

Yes, very common for owners to do this upgrade. The B7 fobs are a lot nicer and are more durable. Provided the frequency and other specs on the B7 remote are the same as the B6 part, either the B6 fob is disassembled and the immo transceiver chip removed and installed into the B7 fob, or a fob that has a virgin immo transceiver is obtained. With VAG-COM, the new virgin immo chip is adapted to the instrument cluster using the standard procedures, or the already adapted chip (removed from an adapted B6 fob,) installed into the B7 fob is re synchronized using the "press fob button insert into ignition switch, turn key ON, press fob button again, turn key OFF, remove key and exit car" procedure is used.
Any Audi dealer can adapt a B7 fob with a virgin immo chip installed, as well as many Euro car locksmiths.

I have a B7 fob, where I inserted the B6 already adapted immo transceiver chip that I removed from one of my B6 fobs, and swapped the key shank from the B6 fob (shank reshaping required,) and all that was needed was the simple re-synchronization, for full functionality.

Remember that the immo function and the remote lock/unlock functions in the fob are totally separate functions within the remote key fob, and the separate functions are dealt with accordingly.

For more detailed info, search Audizine Forum, using "B6 to B7 key fob" search terms.

Edited by: diagnosticator1 on Feb 28, 2010 5:06 PM

Edited by: diagnosticator1 on Feb 28, 2010 5:08 PM