The valet lockout switch is located inside the glove box.
(Off): Press this side of the button to turn the lockout feature off. When the lockout feature is off, you can open the trunk using either the keyless entry transmitter or the trunk release button located near the headlamp switch on the instrument panel.If the valet lockout feature is on it will also disable the Universal Home Remote transmitter, if equipped.
Locking the glove box with your key will also help to secure your vehicle.
See Remote Keyless Entry (RKE) System Operation and Trunk for additional information.