To reset the 1999 Mercury Mountaineer oil change light, please follow these instructions:
1. Turn the ignition to run (one position before starting engine). 2. press and hold the OIL CHANGE RESET control for 5 seconds. The message centre will count down for 5 seconds and the message centre will display “OIL LIFE RESET TO 100%”. 3. Turn the ignition off and then start the engine to verify the indicator has been reset.