!997 Chevrolet Cavalier security light. Computer codes- not on a low end scanner. Repairs for this problem = Replaced ignition key barrel, GM passlock system. Can not get the system to disarm. Have done the ten on three times so many time I have just about worn the replacement lock out.
Went back to the junk yard, got the ECM and gauge cluster from the same wrecked Cavalier as the lock, which was mechanically the twin for mine. Donor was also the same year as mine. Still does not work. My car has never been wrecked, in water, or had no major parts replaced. Have not had any squirrels chewing on my wiring.
Question = How do I get the GM passlock to disarm? See above
Answer: Assuming you have done the relearn procedure correctly, I would suggest you get the car computers scanned for codes with a good scanner. You need to check the PCM and BCM for codes. If there are codes, then go from there. If none, then you need to find a broken wire.
You are using used parts. The IP and PCM are not for your VIN. Even if the same year and make, the part numbers can be different, and the PCM will not be programmed to your VIN.
We do not know of any way to disarm the Passlock or bypass it.