Cadillac Repair: ecu, newer cars, knock sensor

Question
hey whats going on? i recently changed out my ecu on my 1996 deville v8 northstar because my windows wouldn't roll up, the electronics on my dash board were going out, and my trunk won't close. after changing it the car won't crank.

Answer
Hi Deandre,

        On newer cars now when a computor is changed it needs to be programmed or things won't work. In your case the ignition key resistance needs to be learned by the PCM. Otherwise what it thinks is someone is trying to steal the car and doesn't allow the engine to turn over. In years past all that was needed was to change the proms inside. Or it could be a coincidence that the engine isn't cranking. If you still had your original computor I would plug it in and see if it starts. If memory serves there is still a chip inside the PCM behind an access plate that needs to be changed for the knock sensor but that shouldn't make the engine not start. Bill