It's telling you to change the oil.
It's not anything you can do yourself. Any Toyota dealer or well equipped locksmith shop can "flash" the chip in the key.
start with engine off. press and hold that speedometer resetter while starting engine, check engine light will flash a few times then disappear.
There is a reset button underneath the dash just right of the hood latch. Pressing and holding will turn it off. Then let go of button and press it again and tire pressure light will flash 3 times and then reset.
Flash the ECU
yes
On the 08 highlander make sure that your ODO display is on trip A then turn off your key, hold down the trip reset button and with your other hand turn the car to on. the display will flash to a series of either 0's or dashes, they will then countdown to nothing. When the display goes blank the reminder is reset. Since it is reset now do not rely on it for a monitor since it will come on 5k after being reset.
A failing alternator.
To re-set Toyota Highlander 'maintenance required' dashboard warning light: Turn on the ignition and observe the odometer window. Ensure that it is set on the total accumulated mileage of the vehilce (NOT the trip meter). Turn off ignition. With the ignition off - depress the little plastic switch that changes the odometer to the trip meter and then while holding the switch in the depressed position, turn on ignition (it is not necessarry to start the car). Continue holding the swtich down for 5-10 seconds and you will see the odometer window flash back to zero. Release the switch and turn the ignition off, and it will be re-set for another 7,500 miles.
It can be connection wires, bulbs or fuses.
To re-set Toyota Highlander 'maintenance required' dashboard warning light: Turn on the ignition and observe the odometer window. Ensure that it is set on the totalaccumulated mileage of the vehicle (NOT the trip meter). Turn off ignition. With the ignition off - depress the little plastic switch that changes the odometer to the trip meter and then while holding the switch in the depressed position, turn on ignition (it is not necessarry to start the car). Continue holding the swtich down for 5-10 seconds and you will see the odometer window flash back to zero. Release the switch and turn the ignition off, and it will be re-set for another 7,500 miles.
To re-set Toyota Highlander 'maintenance required' dashboard warning light: Turn on the ignition and observe the odometer window. Ensure that it is set on the totalaccumulated mileage of the vehicle (NOT the trip meter). Turn off ignition. With the ignition off - depress the little plastic switch that changes the odometer to the trip meter and then while holding the switch in the depressed position, turn on ignition (it is not necessarry to start the car). Continue holding the swtich down for 5-10 seconds and you will see the odometer window flash back to zero. Release the switch and turn the ignition off, and it will be re-set for another 7,500 miles.
To re-set Toyota Highlander 'maintenance required' dashboard warning light: Turn on the ignition and observe the odometer window. Ensure that it is set on the totalaccumulated mileage of the vehicle (NOT the trip meter). Turn off ignition. With the ignition off - depress the little plastic switch that changes the odometer to the trip meter and then while holding the switch in the depressed position, turn on ignition (it is not necessarry to start the car). Continue holding the swtich down for 5-10 seconds and you will see the odometer window flash back to zero. Release the switch and turn the ignition off, and it will be re-set for another 7,500 miles.