2000 Blazer, ZR2 - The security light stays on, have tried multiple relearn procedures for VAT system, but security light never turns off. Vehicle exhibits classic signs of pass-lock issues, starts but shuts down in 1-2 seconds.

Additional Information: Vehicle was purchased with a bad engine, I put a good engine with 87,000 miles in it. Engine fired right off, but died in 1-2 seconds, tried multiple times with same result.

Checked key and ignition system, found that someone had tried to bypass the security system with a resistor. Replaced the commutator, which included removing the wire in which resistor was installed and key switch, then attempted the relearn process, security light never turns off! Starts but shuts down 1-2 seconds.

Is there something I am missing in relearn process(key off, turn to start, allow key to return to on position and wait and wait and wait for security light to turn off, but it does not!

I believe that there is a issue with PCM, not sure if I should take to dealer and have reflashed or buy new PCM$$$, have flashed or get PCM from junk yard and have flashed(is this possible)?

Can I just carry the PCM to dealer to have it flashed, i.e remove it from vehicle so I do not have to tow it 30 miles?Can someone other than a dealer flash?

Or am I missing boat altogether on this problem???

Need help,
Roger

 

Is there something that I might have missed connecting when replacing engine that is preventing PCM from re-learning? a ground or other? It was quite apparent that there has been a problem in the past with the pass-lock system on this vehicle.