2016 Yukon XL Denali - Remote start only turns on front A/C. Can it turn on the rear A/C?

[brettofthewild]

Recently bought a used Yukon XL Denali. Using an OnStar trial at the moment. When I turn on the car via remote start, it only turns on the front (driver/passenger) air conditioning. Is there a way to get it to turn on the A/C for the rear seats?