1997 Ford Explorer Owner Guide 1st Printing - Page 208

Maintenance and care the on-board diagnostic (OBD-II) system. If your "check engine/service engine soon" light is on, reference the applicable light description in the Warning Lights and Gauges section of your owners guide. Your vehicle may not pass the I/M test with the "check engine/service engine soon" light on. If the vehicle's powertrain system or its battery has just been serviced, the OBD-II system is reset to a "not ready for I/M test" condition. To ready the OBD-II system for I/M testing, a minimum of 30 minutes of city and highway driving is necessary as described below: • First, at least ten minutes of driving on an expressway or highway. • Next, at least twenty minutes driving in stop and go, city type traffic with at least four idle periods. Allow the vehicle to sit for at least 8 hours without starting the engine. Then, start the engine and complete the above driving cycle. The engine must warm up to it's normal operating temperature. Once started, do not turn off the engine until the above driving cycle is complete. 209