Unable to connect to the ECU

[cnut]

My mother's 1998 2.0 Saab 9-3 convertible went into limp mode, then cut out at the weekend after a long journey and wouldn't restart at the time it happened, I suspect it's the crank sensor.

Anyway I tried to scan the ECU yesterday using my cheapy eBay WIFI ELM327 and it wouldn't connect to the ECU.

The scanner definitely works as I have used it on my Alfa and my father's Saab. The only thing that happened was it caused to the fuel pump to continuously prime...

Any suggestions?

Thanks