One problem related to brake light on 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 two separate occasions, the truck has been dead when attempting to crank. There were no lights or devices left on after the previous time the truck had been used. Something is drawing power from the battery causing it to be dead. After recharging the battery, the check engine codes read that there is a problem with �brake light illumination. � help in determining wha t is causing the battery to die on such a new vehicle would greatly appreciated! I'm uncertain at this time as to whether or not the brake light illumination is causing a safety hazard.