When the system has calculated that oil life has been diminished, it will indicate that an oil change is necessary. The CHANGE ENGINE OIL light will come on. The oil must be changed as soon as possible within the next 600 miles (1000 km). It is possible that, if the vehicle is driven under the best conditions, the oil life system may not indicate that an oil change is necessary for over a year. However, the engine oil and filter must be changed at least once a year and at this time the system must be reset. If the system is ever reset accidentally, the oil must be changes at 5 000 km (3,000 miles) since the last oil change. Remember to reset the oil life system whenever the oil and filter is changed.