Having trouble starting car--theft system light blinking--have tried the 10 minute routine and doesn't work anymore. Chevy dealer mechanic first said it was auto start causing it and disconnected it; that didn't work and now he said it's the ignition module--which is expensive from what I understand. They said they checked the key and it's ok; however I read that the '99 Malibu doesn't have a chip in the key. Any suggestions?