Yes that us normal. It is fly by wire meaning that there is an accelerator position sensor which senses how far you are pressing the gas pedal and electronically opens the throttle. In case of a failure of the system there is a limp home mode which mechanically opens the throttle partially when you depress the gas pedal more than about halfway giving you just enough power to limp home. With no power to the system (key off) it is in the mechanical limp home mode and will only open the throttle partially. If you turn the key on and manually manipulate the throttle it will begin to open as soon as you turn it and will open all the way.
Hope that makes sense.
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