how to program 2006 trailblazer ignition key?

To program a 2006 Chevy Trailblazer ignition key, you need to have two working keys. Insert the first key into the ignition, turn it to the "On" position for 10 minutes and 30 seconds, then turn it off. Remove the key and repeat the process with the second key. Finally, insert the new key you wish to program, turn it to "On" for 10 minutes and 30 seconds, then turn it off; your new key should now be programmed.