a4 non start

[abby1]

can you help me i have a4 1997 will not start code reads 17978 where do i look to fix this:zx11:

[Quattros]

17978-ECM Blocked by immobilizer

ecu blocked by immobaliser. yellow key symbol in dass cluster must go out and stay out. try another key, or will need to get key coded again.