One problem related to automatic transmission has been reported for the 2017 GMC Sierra. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2017 GMC Sierra based on all problems reported for the 2017 Sierra.
The contact owns a 2017 GMC Sierra. The contact stated that on several occasions while accelerated at various speeds, the gears inadvertently shifted from high to low and the rpms increased. No warning lights was illuminated. The vehicle was taken to the dealer where the failure could not be determined however, the failure recurred. The vehicle was then taken back to the dealer where it was diagnosed that the valve body, the clutch, the piston, and transmission plates needed to be replaced. The vehicle was repaired however, the failure recurred. The contact stated that while driving, he felt a hard shift into lower gear and felt the gears had shifted and jumped into third gear without warning. The vehicle was taken back to the dealer, but the failure recurred. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 60,000.