1996 Chevrolet Blazer Owner's Manual - Page 127

Engine Coolant Temperature Gage This gage shows the engine coolant temperature. If the gage pointer moves into the red area, your engine is too hot! Malfunction Indicator Lamp (Service Engine Soon Light) Your vehicle is equipped with a computer which monitors operation of the fuel, ignition and emission control systems. SERVICE ENGINE SOON It means that yourengine coolant has overheated. If you have been operating your vehicle under normaldriving conditions, you should pull off the road, stop your vehicle and turn off the engine assoon as possible. In "Problems on the Road," this manual shows you what to do. See "Engine Overheating" in the Index. This system is called OBD I1 (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. (In Canada, OBD I1 is replaced by Enhanced Diagnostics.) The SERVICE ENGINE SOON 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, which may prevent more serious damage to your vehicle. This system is also designed to assist your service technician in correctly diagnosing any malfunction. 2-69