DTC P0122, P0123, P0227, P0228: TP Sensor: Description
WARNING: This page is about a different car, the 2011 Infiniti FX35. However, it is still accessible from the selected car via links, so may be relevant.
Electric throttle control actuator consists of throttle control motor, throttle position sensor, etc. The throttle position sensor responds to the throttle valve movement.
The throttle position sensor has two sensors. These sensors are a kind of potentiometer which transform the throttle valve position into output voltage, and emit the voltage signal to the ECM. The ECM judges the current opening angle of the throttle valve from these signals and controls the throttle valve opening angle in response to driving conditions via the throttle control motor.