The car stopped while i was driving

[aroS3]

Hi quys,
Last night i faced a major problem. (S3 with BAM engine)
When i was driving the car suddently started something like misfire for a while and then stalled. The BIG CHECK engine in the dush lighted on and then dead of course. When i turned the key again the BIG OK sign appeared, the starter turned but there was no any other responce from the engine.
When my friend came with the diagnostic box and after we plugged it we receive the message "NO COMMUNICATION FROM THE ECU". The car is 30 Km away from home and service. Any ideas what to check ?
Do you think it's a general ECU mulfuntion (dead) or could be a fuse or something like that ?
Thanks in advance.

[VST]

Might be the power up relay for the ecu,if the ECU isnt getting enough voltage the diagnostic computer will not be able to communicate.
Failing that sounds like it could be the ECU itself...

[aroS3]

We find what was the problem. We plugged another S3 ECU and the engine strarted but afterwards stalled due to different 7 digit coding which is necessary to unlock the imobilizer.
So unfortunately the problem is the ECU.....
Also now the diagnostic box communicates with the tested ECU as should be normally.