2004 Chevrolet Corvette Owner's Manual - Page 155

Engine Coolant Temperature Gage Malfunction Indicator Lamp Check Engine Light Your vehicle is equipped with a computer which monitors operation of the fuel, ignition and emission control systems. United States Canada This gage shows the engine coolant temperature. If the gage pointer moves into the shaded area, your engine is too hot. This 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. (The larger tic marks are in increments of 30° below 220°F (104°C) and in increments of 10° above 220°F (104°C).) See Engine Overheating on page 5-26 for more information. This system is called OBD II (On-Board DiagnosticsSecond 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 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. This may prevent more serious damage to your vehicle. This system is also designed to assist your service technician in correctly diagnosing any malfunction. Notice: If you keep driving your vehicle with this light on, after a while, your emission controls may not work as well, your fuel economy may not be as good and your engine may not run as smoothly. This could lead to costly repairs that may not be covered by your warranty. 3-41