B5 Key, remote unlocks the car but no start.

[newsh]

Tried the spare key on my RS4 today as I was trying to repair the key that I normally use. I'm pretty sure when I put this spare away a couple of years ago it was working fine but it wouldn't unlock the car on the button. Anyway, I got the key to operate the central locking the car by pressing the buttons while the key was in the door. All seemed to be working as normal. Tried to start the car and it would turn over, fire up for 2 seconds and then die, tried it a few times. there's a flashing "car with key" light on the dash
Seems the immob chip in the key is not triggering immob in the car.

Any ideas how to sort it?

The key I normally use works fine.

I'm sure I had a proiblem like this back when I first got the car and I'm not sure how I fixed it, I know I had the dash out at one stage.. Or maybe I didn't fix it, I just swapped keys??

[Ruffiano]

is there a key symbol flashing on the dash? that would be telling you the IMMO is stopping it from running

[newsh]

is there a key symbol flashing on the dash? that would be telling you the IMMO is stopping it from running

Yes, key symbol is flashing.

But I've been doing some googling and I just read something else.

"the remote switch and battery are in one half of the keyfob, the immob chip is in the other half with the physical key"

So, I swapped the top half of the casing (which was broken) with a key that I was given from another car, so I think I've inadvertently swapped the immob chip as well.

So I either need to swap the casing back or code the chip in the key to the immob in the car (which I don't know how to do).

[Ruffiano]

you just need to move that immobilizer chip into the new casing.

[newsh]

B5 Key, remote unlocks the car but no start.

Ah, that side of the key does come apart then!
I took out the small screw under the Audi rings and tried levering it but no joy, I'll have another look.

Thanks

[pcfnet]

Do you have vcds cable? If you have then it's possible you can program the chip on your key to the immobilizer. I've done that to my rs4 but with a bit of trick to get the key code by a software. Let me know if you want to go this approach.

[pcfnet]

Something like this to get the code.

Here is the software :

http://nefariousmotorsports.com/forum/index.php?topic=1168.0title=