Alarm and running problems

[THE MONSTER]

Audi A4 B5 1997 1.8t ..I have been having starting problems first of all it was running ok on the road till you came to start it next day and it was cold..I did a manual Throttle body set...but still was the same...

Now I cannot start it at all after disconnecting the battery because it needed charging and tried restarting it..

I noticed might have nothing to do with it but the yellow car light on the dashboard know as the immobiliser is flashing when the ignition is on(is it supposed to do that never noticed before)but when I try to start the car it wants to start but just fades out after a couple of revs like the immobiliser is kicked in..

I tried taking the fuse out for the immobiliser but is connected to the ignition..


Any ideas welcome..

 

[THE MONSTER]

On further investigation I found that is what they call the dreaded flashing yellow immobiliser symbol ..

With having the battery off or spending the day running the battery down the ecu has not recognised the code in the ignition key that is being used..

Is it a case of resetting the code with vagcom if so can you instruct me further...