One problem related to warning has been reported for the 2020 GMC Sierra 3500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2020 GMC Sierra 3500 based on all problems reported for the 2020 Sierra 3500.
My intellibeam function stops working sometimes, I can still use the lights as normal but the intellibeam function stops every so often and starts working after about 2 to 10 mins. Lane departure warning stops every so often and will start working after 1 to 10 mins, I have noticed that when it stops working at night time then the intellibeam function stops working also. When I press the on/off button for lane departure then it will say that lane departure is unavailable right now. I have been getting a p20ee code showing something is wrong with scr nox sensor 2. Scan tool reveals that the sensor works normal and then stops. Once I clear the code then it works good for a few days.