The throttle position sensor provides a signal to the controller to determine how much voltage and current from the battery pack is passed to the motor. The sensor is an automotive grade potentiometer – a 5,000 Ohm resistor with a sliding contact that measures a variable portion of the resistance depending on position.
The sensor needs to be mounted in the same location as the throttle body of the gas engine. The throttle linkage is routed through a bellcrank on the transmission, so I decided to mount my throttle position sensor to the transmission adaptor plate to avoid throttle surging due to torque induced twisting of the transmission during acceleration.
The adaptor plate has a cutout feature at the bolt mount that I used to key the throttle bracket.