1998 Chevrolet Venture Owner's Manual - Page 210

Malfunction Indicator Lamp (Service Engine SoonLight) NOTICE: SERVICE ENGINE SOON United States CHECK Canadian 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 notas be good and your engine may not run as smoothly. This could lead to costly repairs that may not be covered by your warranty. This light shouldcome on, as acheck to show youit is working, when the ignitionis on and the engine is not running. If the light doesn't come on, have it repaired. This light will alsocome on during a malfunction in one of two ways: Your vehicle is equipped with a computer which monitors operation of the fuel, ignition and emission control systems. This system is called OBD I1 (On-Board Diagnostics-Second Generation) and is intended to assure thatemissions are at acceptable levels for the life of the vehicle, helping to produce a cleaner environment. The SERVICE ENGINE SOON light comes on and achime will soundto indicate that there is a problem and service is required. Malfunctions often will be indicatedby 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 technicianin correctly diagnosing any malfunction. 0 Light Flashing -- A misfire condition has been detected. A misfire increases vehicleemissions and may damage theemission 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. 2-93