One problem related to wiring 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.
On December 14, 2020 my sierra with 2339 miles displayed, at startup, the power steering was out, to drive with care. Also displayed service esc and traction control failures. I drove with much difficulty, without power steering, ten miles to the nearest GMC dealership, lafontaine in highland, mi. I picked up the vehicle on December 29, 2020 with an additional 60 miles. The service personnel said they were unable to duplicate the problem, therefore no repairs were made. Lafontaine had contacted general motors tech center who offered no solutions other than checking the battery and wiring harness connections. The problem has not reappeared in the fifteen days since I picked up my vehicle.