Fiat Grande Punto starting issues

[adam2896]

I have a 2006 (56) fiat grande punto 1.4 active sport,
The car has been left for 2 years standing on a driveway purely as a family member has been away in university.
After replacing the battery and doing minor repair work I’ve found the car doesn’t want to start at all,
The car will crank (turn over) for a few seconds and then shut off, and immobiliser light will come on.

Battery voltage is good, no fault codes, earth appears to be ok (I haven’t removed this to check, but no resistance)
A friend of a friend has come out to have a quick look, and tried to obtain a key code from the BCM/BSI and the software he was using suggested the information on the control unit is corrupt?
Then advising the BCM, ECU and lock set needed to be replaced but trying to find one for a 1.4 3 door punto is becoming difficult.
Has anyone has similar issues?

Thanks!

[Chris32345]

Check the fuses boxes for water and the run a jump lead from the battery to the engine to check for a bad earth cable