03 ION Why would it not start in cold weather works fine at running temp or in warm weather?

The grease in the ignition becomes 'frozen' in the colder weather. When you insert the key and turn, it triggers the anti-theft system. The 'solution' to this problem is to keep a lighter in your car and heat the key up BEFORE you insert and turn to start the engine. If you trigger the anti-theft system, you are going to have to wait 10 minutes for it to reset. Another problem could be in the ignition switch The switch contains the anti-theft logic and is suseptible to moisture This is a very common problem. If your security light flashes when it won't start it's your problem for sure Also if you have the codes checked it will have B2960 and B3033 in the body control module history