the light coming on is a good thing. If it was an immobilizer issue the light would be on.
What was happening before it wouldn't start? Symptoms? check engine light?
you know you're getting fuel as in you pulled a spark plug and it was wet with fuel?
The check engine light is coming on, indicating power at the ECU, yeah?
getting battery voltage to the coils?
the harness on the passenger side, is known to have issues where there is a hard bend in it.