Brocka2203

I owned my truck for about 2 years and I started doing my rear brakes without knowing about the service mode or anything. I took the caliper and rotor off and started refreshing…. When I go to put the caliper on I notice it’s way too far out. I use the social notched caliper tools and start turning and pushing in… it stops and is very hard. I tried putting truck into service mode and all I get is a solid yellow wrench with and bunch of service rear brakes and parking brake warnings… any help please

Doing rear brakes on my 2019 Chevy Silverado lt. I got the caliper off and the rotor and when I put the caliper tool on it to spin and push it in… it has too much resistance. I did the turn the truck on and hold the park brake and the light is on solid now with the wrench any help please!!!