1998 Cadillac Seville Owner's Manual - Page 131

Malfunction Indicator Lamp (Service Engine Soon Light) I 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 as be good and your engine may not runsmoothly. as This could lead to costly repairs that may not be covered by your warranty. Canada This light should come on, asa check to show youit is working, when the ignition is on and the engine is not running. If the light doesn't come on, have it repaired. This light will also come on during a malfunction in one of two ways: SERVICE ENGINE SOON United States Your vehicle is equipped with a computer which monitors operation of the fuel, ignition and emission control systems. This system is calledOBD 1 (On-Board 1 Diagnostics-Second Generation) and is intendedto assure that emissionsare at acceptable levels for the life of the vehicle, helping to produce a cleaner environment. The SERVICE ENGINESOON light comes on to indicate that there a problem and service is is required. Malfunctions often willbe indicated by the system before any problem apparent. This may prevent is more serious damageto your vehicle. This system is also designed to assist your service technician in correctly diagnosing any malfunction. Light Flashing-- A misfire condition has been detected. A misfire increases vehicle emissions and may damage the emission control system on your vehicle. Dealer or qualified service center diagnosis and service may be required. Light On Steady -- An emission control system malfunction has been detected on your vehicle. Dealer or qualified service center diagnosis and service may be required.