2009 GMC Savana Van Owner's Manual - Page 152

Tire Pressure Light For vehicles with a tire pressure monitoring system, this light comes on briefly when the engine is started. When the Light Flashes First and Then is On Steady This indicates that there could be a problem with the Tire Pressure Monitor System. The light flashes for about a minute and stays on steady for the remainder of the ignition cycle. This sequence repeats with every ignition cycle. See Tire Pressure Monitor System on page 5-65 for more information. It provides information about tire pressures and the Tire Pressure Monitoring System. Malfunction Indicator Lamp Check Engine Light A computer system called OBD II (On-Board Diagnostics-Second Generation) monitors operation of the fuel, ignition, and emission control systems. It ensures that emissions are at acceptable levels for the life of the vehicle, helping to produce a cleaner environment. This light should come on when the ignition is on, but the engine is not running, as a check to show it is working. If it does not, have the vehicle serviced by your dealer/retailer. When the Light is On Steady This indicates that one or more of the tires is significantly underinflated. A tire pressure message in the Driver Information Center (DIC), can accompany the light. See DIC Warnings and Messages on page 3-48 for more information. Stop and check the tires as soon as it is safe to do so. If a tire is underinflated, inflate to the proper pressure. See Tires on page 5-55 for more information. 3-34