so just bought an a4 2.0 L tdi 2006 06 plate (private sale) with one key fob that never worked and knew this when took it, thought would be an easy fix bought new battery from shop, turned out there was not even one in the fob, have been following instructions from the internet trying various pressing patterns and in door lock and master key in ignition while fob in door trying things and nothing seems to work???

is a brand new battery and the small red led light on fob works when a button is pressed, but really want it working as struggling to use the key in the door and get all the doors open

anyone give any help, really was trying to avoid the dealer with their prices

 

Does that key start the car? If it is truly the fob from that car, you can relink it to the car with the procedure in the manual. IIRC, it's pretty much just hold down the unlock button while you turn the key to ON (not start) and back off. Maybe twice. I forget exactly. It's in the manual. I have to relink mine most of the time I disconnect the car's battery to do work.

 

Here is what the manual says:

1. Press the unlock button on the FOB
2. Insert key into ignition and turn to the on or accessory position (do not crank the engine or start the car)
3. Turn the key back to the off position and remove
4. Press either the lock or unlock button on the FOB to complete the reset sequence.

 

thanks for the replies guys much appreciated, and yes the fob opens the door as it should and also starts the car exactly as it should, the small thin black plastic master key thing that was in the wallet also lets me enter the car and start it without issue and works as it should.
just cant seem to get the open and lock buttons on the remote to work?
the thought had crossed my mind that possibly the orginal keys were lost and this was one purchased and cut using the original master key thing maybe? the previous owner did not own it that long and it had never boithered him apparently, or maybe he knew and was lying who knows, cant trust anyone these days really can you, however the car is fine other than a few wee niggle i will sort was just this key

 

if it has been a key thats been bought at some point and not an original key, someone obviously had it cut etc to work with the car and bought it, seems odd they wouldint just code it at the same time i know i owuld if had went to the expense? but IF they have just not done that part is there still not a way i can do it? IF this is the case which i have no idea?

Grant

 

That's why I asked if it starts the car. If it does, it's been coded to the immobilizer (whether original or done by a dealership). If that's the case, there's no reason you can't program it with the sequence rhodes gave. Never heard of that not working with a key that is properly mated to the car.

Have you tried that sequence with the non-working fob? The only thing vague about it is that you need to HOLD the unlock button while turning the key to on, back to off, and pulling it from the ignition. Do this with the non-working fob and report back.

 

Have you tried that sequence with the non-working fob?

I only got the one fob and is the one i am talking about, the only other thing as said above is the thin black master key i believe its called (could be wrong)

i will go out now and try the above again just now with holding the button all the time, but sure i have already tried that.

However so the fact that the key/fob opens the door as it should and starts the car as it should with no problems means that at some point at least it has deff been programmed to the car and the buttons must have worked at some point previously?

 

just went out and tried that numerous times, even tried pressing the lock button while doing the process as well as trying the unlock button, pressing it before putting key in lock, and holding the entire time and letting go once key removed from lock.
Also tried putting key in lock then pressing and holding button before turning to on etc, tried both buttons doing ti that way then back to first way and still nothing? totally stumped here

 

I don't know if this is right, but I think you need to either have the driver's door open or closed for the process to work. If I remember correctly it has to be open. Does anyone else recall if this is correct?

 

I'm not positive, but I think I've done it both ways. Usually open because I'm too lazy or it's too hot to pull my leg in and shut the door.