I was having some starting issues with my 2001 C5 Coupe. I would turn the key and there would be a long delay before the starter engaged. On one trip to the store it was dead and nothing happened for a long time.
I recalled a starting issue a few years ago when it was still under warranty and the dealer fixed the problem by ordering a new key. I changed keys to my backup and it starts fine now.
Who would think a worn out key would cause such a problem. Now how to obtain a replacement key. As I recall the dealer had to order one from GM