I am glad to be a part of the Trailvoy community. I own a 2005 GMC Envoy Carbon Metallic 4.2 6 cyl engine. I was looking for info on Ignition Switches and came accross this site. This evening, my truck shut down on me and i was told that the ignition switch needed to be replaced. It is now sitting at the dealer to be looked at on Monday. I am not sure of the cost to replace it.