The power button is used to turn the vehicle on and off.
Auto:
The Auto button is used to engage the automatic transmission. When the Auto button is pressed, the transmission will automatically shift gears based on the vehicle's speed and engine RPM.
E-AT:
The E-AT button is used to engage the electronic automatic transmission. The E-AT button provides the driver with more control over the transmission than the Auto button. When the E-AT button is pressed, the driver can use the gear selector to manually shift through the gears.