P2118 Throttle Control Motor: Description
WARNING: This page is about a different car, the 2009 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor. The throttle position sensor it provides feedback to the ECM, when opens/closes the throttle valve in response to driving conditions via the throttle control motor.