The problem stems from a faulty security system. I know because my 97 Grand Prix GTP has been doing the same thing every summer for about 3 years.
I have yet to find a permanent fix that I am willing to do.. I've read afew internet posts that say a new chip for security system will fix it. Also that it is related to a sensor having to do with the ignition, that the key being offset (or not a master) can cause the system to lock you out, assuming tampering. A heavy keychain can also cause the same system to lock you out.. and I assume repeated use of a REALLY heavy one could damage the system.
Disconnecting the negative on your battery will reset the system (including your radio) and using the selenoid switch under the steering column will release the key.
I am still searching for a permanent fix to the electrical system, security, or selenoid that will not cost me an arm and a leg.
Hope this helps.. if anyone can add anything I'd appreciate some feedback as well.
