Hi There

To remotely shut the engine off you press the same button in the same manner as you do to remote start the vehicle. Also if you are in the vehicle and wish to leave it running , say you are wanting to go in to a store but leave the vehicle running press the remote start button turn off the key dont press the brake pedal and exit the vehicle the vehicle will stay running(Keyless running mode)

The AUX button is used for trunk release if applicable and to hook this option up it is normally 30.00.

Provided your vehicle is equipped with a power trunk release button , not a cable release handle that is pulled

Hope this helps

Terry