From 2002 through 2009, GMC Envoy and Chevrolet Trailblazer used the same factory keyless entry system. The replacement remote transmitter for this system is Remotes Unlimited part 610-1610. This 3-button keyfob has FCC ID MYT3X6898B and several GM part numbers, including 15051014.
Any factory keyless entry system must be programmed to accept a new remote keyfob. For 2002-2009 Chevy Trailblazer and GMC Envoy, systems are user programmable. Remotes Unlimited includes easy-to-follow programming instructions with the purchased part.