2004 Ford Explorer Sport Trac Owner Guide 3rd Printing (Spanish) - Page 462

Maintenance and Specifications Board Diagnostics System (OBD-II). This OBD-II system protects the environment by ensuring that your vehicle continues to meet government emission standards. The OBD-II system also assists the service technician in properly servicing your vehicle. When the Check engine/Service engine soon light illuminates, the OBD-II system has detected a malfunction. Temporary malfunctions may cause your Check engine/Service engine soon light to illuminate. Examples are: 1. The vehicle has run out of fuel. (The engine may misfire or run poorly.) 2. Poor fuel quality or water in the fuel. 3. The fuel cap may not have been securely tightened. These temporary malfunctions can be corrected by filling the fuel tank with good quality fuel and/or properly tightening the fuel cap. After three driving cycles without these or any other temporary malfunctions present, the Check engine/Service engine soon light should turn off. (A driving cycle consists of a cold engine startup followed by mixed city/highway driving.) No additional vehicle service is required. If the Check engine/Service engine soon light remains on, have your vehicle serviced at the first available opportunity. Readiness for Inspection/Maintenance (I/M) testing It may be a legal requirement in your area to pass an I/M test of the on-board diagnostics system. If the system or battery has just been serviced, the on-board diagnostic system is reset to a "not ready for I/M test" condition. To ready the system, allow the vehicle to sit for at least eight hours without starting. Then, start the engine and complete the following driving cycle: 1. Drive on an expressway or highway for at least 10 minutes. 2. Drive in stop-and-go traffic for at least 20 minutes with a minimum of four idle periods. The engine must warm up to its normal operating temperature. Once started, do not turn off the engine until the above drive cycle is complete. Note: If your "Check Engine" light is on, your vehicle may not pass an I/M test. 204