For 1990-2009 cars

The power door lock switch is located on the instrument panel.

(Door Lock): Press to lock the doors, liftgate, and the fuel tank door. The button will illuminate when locked. Press again to unlock.

If the driver's door is not closed properly, the power door lock switch will not lock the doors.

When the vehicle has been unlocked, the key is not in the ignition, and no door is opened the vehicle will automatically lock itself again after one minute.