put the prom from one of my 92 Camaro computers into the other 92 Camaro computer it ran fine for a minute installed. I put the original prom back in and it wont start. no crank. did I possibly mess up the ecm?

 

The ECM won't prevent the starter motor from cranking the engine. It may be a VATs issue though... If the Security light stays on, VATs.

RBob.

 

Well heres the thing. No security light what so ever. Let me give a little more in depth info. Prom that was originally in the ECM is back in. Still no crank. When key in on position left side of dash dimly lit up while right side is dark. Only lights to come on when key is turned to on is the seatbelt and restraint lights. No check engine, no security light, nothing. When key on and i pull the headlight switch to turn markers on, then the left side of dash is dark and the right side lights up dimly. Now when i pull the smaller connector at the ECM and key to on, the security light is lit dimly.... Plus when everything is all plugged back in and the key is on, the alternator hums a bit as does the TB unit. Thd ign coil buzzed before but now i put a new battery in yesterday and the buzzing stopped. So do you still think VATS, espacially with no security light? Plus i cant pull any codes either... Not sure whats goin on exactly

 

Update. Was going through a couple of test procedures and made some slight progress. Was testing the pass key module and wasn't getting the readings i was supposed to get so I moved along further in the test tables. Proceeded to mess with the starter enable relay by jumping it and starter cranked over. Now the reading I was supposed to get at the vats module were there. This also got my gauge cluster back to normal, put the relay back in and now the dim cluster problems gone and I have all my test lights back illuminated. Not sure why this happened but maybe there was a bad contact at the enable relay? How did swapping the prom mess with this I don't know. None the less. Got crank and fuel but no spark. Tried swapping in a known good coil and still no spark. I can't remember but does the ECM control the spark cause I'm thinking now it's either the Ign Module in the dizzy or the ECM... Any suggestions?