So I looked up the code and I’m going to be completely honest with you, I don’t know much about Chevy’s. With what you said and after looking up the code, is it possible you damaged the wiring to the rack when you damaged the rack? If you know for a fact you did not then you should google if that needs to be reprogrammed to your vin from the dealer. Fords need to be reprogrammed.. I’m not sure if yours might need to be. But, look at the truck harness and make sure the wires look OK.