My 2013 SL's power rear liftgate works when I use the FOB or when I press the control within the vehicle, but not at the liftgate itself. When I press the button at the gate, it only opens about an inch like it would if there was no power. I reviewed the manual, but did not see where there is a switch my wife could have accidentally pressed to disengage the use of the button at the gate. Any ideas would be helpful. It's under warranty, but if it is operator error I would rather not waste the dealerships time.