Hi
I signed up as a public service for those who are having the GM passlock problem I had. My problem was the one where the key does not appear to be getting "read" by the security system, so passlock disables the car from starting for 10-20 minutes and then the car will start.
I was getting the problem a lot this summer. Tried all the "Reset" fixes people were posting in the internet. (Sequences about turn off & on 3 times, lights off & on 3 times, etc.)
One day, when I put the key in I noticed there's an extra millimeter of "play" where I can push the key farther in before I turn the key. OK, I said, lets be pushing the key further in when I'm turning it, so the car does a better job of reading the security magnets or resistors in the key.
It worked and I haven't had a single passlock "timeout" problem once since then. Every time I put the key in, I make sure I'm pushing it all the way in before I turn the key.