GTV 3.0L 24V will not start
Code light wouldn't go out, engine would not fire.
The answer was the ECU power up relay (£8.50 from Alfa). There are two located on a relay bank under the plastic cover of the F/O/S wheel. One powers the other which in turn powers up the ECU. An easy check if you have the same problem.
A month later, same problem - this time it was a dodgy connection on the low voltage cable going into the yellow immobiliser module strapped to the steering column under the dash. A good clean up of the 2 plugs and module connections solved this problem.