help..toledo not starting

[vw754]

seat toledo 'V' -reg battery was disconnected and a new one fitted after 2 days,now car dont want start,immobiliser symbol flashes on the dash.

It starts and runs for around 1-2 seconds then cuts out....any ideas on what to do ?

I do have vag-com.........

 

[longman]

I think this is an immobiliser fault.

This is the same symptom as when you are starting with no transponder to switch it off.

Not sure why it wouild suddenly stop working. Perhaps you could check in the instruments controller in adaptation (Channel 21) to see how many keys are stored.

If the field is 0, then you know you have a problem

 

[Uwe@Ross-Tech]

First thing that should be done is check the immobilizer for fault codes. If the car didn't start due to an immobilizer issue, it's almost certain that a fault code was stored as a result. It is exceedingly rare that keys spontaneously become unmatched, and the transponder in the key itself is probably the most reliable component of the whole immobilizer system. So chances are, the problem lies elsewhere.

-Uwe-