2007 GMC Envoy Owner's Manual - Page 209

Tire Pressure Light This light will come on briefly when you turn the ignition to RUN. If your vehicle has a Driver Information Center (DIC), a CHECK TIRE PRESSURE DIC message will accompany the light, see DIC Warnings and Messages on page 222 Stop and check your tires as soon as it is safe to do so. If underinflated, inflate to the proper pressure. See Tires on page 439 for more information. This light will flash for approximately 70 seconds and then turn on solid if a problem is detected with the Tire Pressure Monitor system. See Tire Pressure Monitor System on page 448 for more information. This light will also come on when one or more of your tires are significantly underinflated. 209