Technical Won't start, ECU fault?

[robster1138]

I have a 1.2 punto, 03 plate. After starting it up today the power steering died, then the engine soon followed. It turns over but won't fire. Upon turning the key part way the lights on the dash/fule gauge would go on and off at random.
A mobile mechanic has said that it reported an ECU fault and I should take it to a fiat dealer. I am worried after looking at some of the threads that first I need to get my car towed there, then could get charged £300 for a new ECU ! Is there any way I can tell for sure that's the problem? Is it worth unplugging the battery first as I have read?

 

[T14086]

complete ECU failure is very rare,normally it runs on 2 cylinders....i'd look closely at the ignition switch especially the ignition orange wire.

 

[robster1138]

I think I will tow it home in the morning and have a fiddle with that first then. I am not remotely mechanic but I cant afford any major expense. Is it worth me trying the spare key as someone suggested the key could be at fault and affecting the immobiliser?