I have a 1999 Blazer 4x4 with the AutoTrac feature. I turn that on and when the rear wheels slip it does work properly by going into 4-HI, but it won't go out of 4-HI and I get a 'Service 4wd' light. When I push the 2wd button I can hear a relay clicking, but it still won't go out of 4-HI. Before when this happened I could park, turn off the truck, start back up, and then shift back into 2wd, but now it won't let me. Can I read the codes myself or does it take a special scanner to pull these codes? Any ideas would be appriciated.
Thanks,
John