My 05 Tahoe has 2 issues when it gets wet (rain, car wash, melting snow, etc.). 1. When it gets wet, the buttons for Auto4WD, 2wd, 4H, 4L randomly light up, and sometimes even the red neutral light is on. The Tahoe is not really in whichever is lighted, but I can't change from one to the other either. This is not serious unless I'm driving in snow and want to use 4wd and can't select it. Took it to mechanic one rainy day, he could not get a code. And, when the Tahoe is wet it also misfires. I can't hardly get enough power to start out from a stop sign without it feeling like it's going to die. Code for this said I need new plugs & wires (couldn't tell which one, so change them all). I keep thinking it's something with the wiring getting wet but no one can tell me for sure.

 

Maybe the actuator has a short