Auto Electronics: Theft system, haynes repair manual, chevy malibu

Question
I have my my 99 Chevy Malibu for 7 years now, the problem just started a year ago,elvery now and then [at random and when im late for work] the vehicle will not start and the THEFT SYSTEM light comes on and the vehicle wont start.After about 10 minutes or so the light goes off and the vehicle starts.This has not happend for the first 6 years i had the vehicle and i was not aware it had a theft system, nothing in the Haynes repair manual covers this. Again this happens now and then when you least expect it and it is quite anoying. Any input would be appreciated.

Answer
Diane, it sounds like you do indeed have a problem with the GM anti theft system. This particular system is very susceptible to problems with the pass-lock sensor, located in the ignition lock cylinder. As the key is turned in the ignition cylinder, a signal is sent by the sensor to the body control module. If correct, this signal will permit the vehicle to start. If not, the body control module will tell the powertrain control module not to allow the vehicle to start. Your Malibu has a problem somewhere in this system and you will be best served by taking it to someone who has the expertise and correct GM scan tool to diagnose it. Hope this helps. Don.