2005 Pontiac Aztek Owner's Manual - Page 156

Engine Coolant Temperature Gage Malfunction Indicator Lamp Service Engine Soon Light in the United States or Check Engine Light in Canada United States Canada United States Canada This gage shows the engine coolant temperature. If the gage pointer moves into the red area, your engine is too hot! It means that your engine coolant has overheated. If you have been operating your vehicle under normal driving conditions, you should pull off the road, stop your vehicle and turn off the engine as soon as possible. See Engine Overheating on page 5-26. Your vehicle is equipped with a computer which monitors operation of the fuel, ignition, and emission control systems. This system is called OBD II (On-Board Diagnostics-Second Generation) and is intended to assure that emissions are at acceptable levels for the life of the vehicle, helping to produce a cleaner environment. The SERVICE ENGINE SOON or check engine light comes on to indicate that there is a problem and service is required. Malfunctions often will be indicated by the system before any problem is apparent. 3-34