2003 Chevrolet Silverado 1500 Pickup Owner's Manual - Page 200

Notice: Modifications made to theengine, If the Light is Flashing transmission, exhaust, intake or fuel system of your The following may prevent more serious damage to vehicle or the replacement of the original tires with other than those of the same Tire Performance your vehicle: Criteria (TPC) can affect your vehicle's emission Reducingvehiclespeed. this light to come on. controls and may cause Avoiding hard accelerations. Modifications to these systems could lead to costly Avoidingsteepuphillgrades. repairs not covered by your warranty. This may also result in a failure to pass a required Emission If you are towing a trailer, reduce the amount of Inspection/Maintenance test. cargo being hauled as soon as it is possible. This light should come on, as a check to show you it is If the light stops flashing and remains on steady, see "If working, when the ignition is on and the engine is the Light Is On Steady" following. not running. If the light doesn't come on, have it If the light continues to flash, when it is safe to do so, repaired. This light will also come on during a stop the vehicle. Find a safe place to park your vehicle. malfunction in one of two ways: Turn the key off, wait at least 10 seconds and restart the engine. If the light remains on steady, see "If Light Flashing - A misfire condition has been the Light Is On Steady" following. If the light is still detected. A misfire increases vehicle emissions flashing, follow the previous steps, and drive the vehicle and may damage the emission control system on to your dealer or qualified service center for service. 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. 3-45