2005 have stepper motor issues with the instrument cluster. A lot of people fix it themselves. You should be good with your warranty. Although, they should fix the instrument problems outside of your warranty, since it was an issue at the beginning.
chevy runs deep, Don't step in chevy!
67 Coupe 289 - TCI C4 w/2k stall; Holley 4150 570cfm; Performer intake; mild cam; Pertronix HEI; 302 heads; Roller Tips; Hedman Tri-Y headers; H-pipe w/Flowmaster 40's; 9 in posi 3.50; 205/50-17F; 225/50-17R.