Long story short: Shop lost my only key (with the anti theft chip on it). Apparently it was stolen. Yeah right, nothing else in the shop or my car got touched though. GM dealer was able to make new key and make it start the car but now that security light stays on. So I assume the antitheft function is toast now. The shop I deal with now cannot even access this system with the OBDI or II diagnostic tool. I guess I can just put black tape over the light. Anyone have any ideas?

 

If there are no "chip" on the new key the car shouldnt even turn over...
If VATS senses a invalid key it shuts down the injectors and starter enable relay... its strange that the Security light is on when the car is running..
How did they know that they gave you the correct key value, there is 15 different keys..

 

The new Key does have a chip on it. I remember that it took the GM guy 2 days to get it to start because I had to fly him 650miles one way. I have no idea which of the 15 key values it would be. Maybe he had to go thru them 1 by 1 till it worked. I couldn't hang out with him when he was doing it because I had to work. The car starts and runs fine anyhow. The light is annoying though.

 

Try disconnecting the battery cable for 10 minutes and then start her up (thats resetting the ECM) maybe theres nothing to it. get back with some info after you resett the ECM..

 

That doesn't work as I've had the battery out every winter since this happened. Various other times too. Nice try though

 

Well then you have to check the circiut and measure some cables (be carefull when you / if you do this.. Disconnect battery before measuring the cables..
Maybe you have some "glitch" somewhere, maybe he bypassed VATS and you dont know that ? If you wish to let the security light go away (and not use VATS) just disable it in the prom..

 

Thanks King, but sadly I have no idea how to do anything with the prom. Let alone find it. (yes I'm embarrassed) Do you mean disable it via the OBD code scanner? When I had one hooked up last week we couldn't even access VATS thru it. So I'm thinking he probably did bypass VATS. Time to start researching PROM.

 

tpiparts.net sells custom proms, you could asked them. If you disable the VATS in the prom the light shall come off. there will be some $$ in the prom, but you will also gain some hp with an prom or just remove the lightbulb in the dash (I dont think I would have done that myself but its an option)

please let me now how it turns out for you