Throttle Valve Potentiometer
This potentiometer is located on the throttle valve shaft, opposite the accelerator cable attachment. It is switched as a current divider, the potentiometer brush representing the throttle valve opening angle. The control unit recognizes the throttle valve position by measuring the brush voltage at terminal "C".
This voltage signal is one of the control unit input variables for determination of the exact air/fuel ratio. In addition, it also automatically communicates the important information of whether the vehicle is accelerating or decelerating via the voltage change or voltage jump in the throttle valve signal.
When the throttle valve is closed, the sensor signal is approx. 0.65 volts. The voltage at fully opened throttle valve is approx. 4.8 volts.