One problem related to brake loud noise has been reported for the 2020 GMC Sierra 1500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2020 GMC Sierra 1500 based on all problems reported for the 2020 Sierra 1500.
Highway driving engine light started flashing, received codes on service esc and service parking brake. Truck seemed to loose power transmission started shifting very hard, cruse disengaged,lane keep assist stopped working , brakes and steering seemed to act different . When ignition was turned off loud noises from under truck sounded like brakes releasing with loud clunking noise.