Engine no crank, anti theft light on steady?

Hello,

The first thing I need to ask is what your key looks like. Certain cars have the anti-theft chip in the key. I have attached a picture of a key that may look similar to yours. If yours does not have the "pellet" just below the head, let me know.

FYI, I am a locksmith.

If your key has the "pellet" in it, try another key. If you do not have another key, most likely the "pellet" went bad. All the "pellet" is is a resistor chip. The early GM anti-theft keys had only a handful of different resistances. If you have a key cut on the wrong blank, the key will turn, but the car will not start. If you were to have taken the working key to a locksmith, they would have checked the resistance in the key, and used that code to get you the proper replacement.

I have also attached the relearn procedures just to ensure you have the correct information.

I would first take your key to a local locksmith (usually less expensive than the dealer) to have them test the key. If the key is good, we can look into other issues. Please let me know.

William

Hello,

There are two small wires that go to the ignition switch tumbler that break causing the security light to come on. I would remove the steering wheel and top plate to see if I am right.

Here are diagrams to help you get the job done.

Check out the diagrams (below).

Please let us know what you find. We are interested to see what it is.

Cheers, Ken

The new computer has to relearn the security codes.

Disconnect the battery and hold the cables together for about 30 seconds then reconnect the cables before performing the procedure. Read it carefully if done incorrectly it won't work. If it helps let me know.
Turn ON the ignition, with the engine OFF.
Attempt to start the engine, then release the key to ON (vehicle will not start).
Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
Turn OFF the ignition, and wait 5 seconds.
Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes (the vehicle is now ready to relearn the Passlockâ Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK).
Important
The vehicle learns the Passlockâ Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.
Start the engine (the vehicle has now learned the Passlockâ Sensor Data Code and/or password).
With a scan tool, clear any DTCs if needed (history DTCs will self clear after 100 ignition cycles).

I forgot to ask but has your new PCM been flashed yet?

Y did you replace the cpu?If for the security lights on I would have tested the ohms reading on the key. Then insert the key in the cylinder. Then youll see a orange harness with 2 white wires. Go to the connecter at the base of the steering column. Read the ohms reading at the connecter on the 2 white wires. It should read the same as the key. Or you will need to replace the key cyl. To repair

This is a Passlock system. It doesn't even have resisters in the keys.

This sounds like the drivers door latch needs to be replaced because the micro switch inside goes bad. But to be sure let try to reset the system first by following this guide.

https://www.2carpros.com/articles/how-to-reset-a-security-system

Please run down this guide and report back.