2003 Saturn ION 1 from North America - Comments

Go to Autozone or Advance auto and let them scan your car. Do you have bosch spark plugs, because I heard they would cause problems like you described not good for GM cars.

The car not starting when it is cold is a very typical problem. If you are handy you can replace the ignition switch yourself... it is not the tumbler assembly, but a plastic piece on the bottom side to the left of the tumblers. It costs about $250 for the dealer to do it. I did it myself for like $40.

The tricky thing is you have to reprogram the theft deterrent system to recognize your key. It takes a half hour to do. You have to put your key in turn it to start (which it won't), then leave it on for 10 min or until the theft light goes off. Then turn to start again and wait 10 min then repeat one more time. After a half hour the next time you start it, it should work. The root cause of this is some type of oil in the plastic piece that gets too thick when it is cold and doesn't send the signal from your key thru the theft deterrent so it makes the car think it is getting stolen... thus making it not start for 10 minutes.

My wife got stranded a bunch of times, called me and it would start before I got there. Finally I got fed up and started looking around on the internet and found out it was very common. When I went to the dealer and asked for the ignition switch, he tried asking what part of the ignition I needed. I kinda glared and said the ignition switch, ya know, the one that you keep replacing on Ions cause it gets cold? Yeah, that one. He went and got me the part right away.

I think the only thing special tools wise is some torx bits... I forget what size and a metric socket set. Also, when taking off the switch you need to have your key in the ignition to unlock the switch from the tumblers... have fun.