Tracer L4-116 1.9L SOHC (1991)
Throttle Position Sensor: Description and Operation
Throttle Body Assembly
The Throttle Position (TP) sensor, mounted on the throttle body, is a potentiometer that monitors throttle plate angle and sends a signal to the Electronic
Control Assembly (ECA). The TP sensor contains a pivot arm that moves along a curved resistor. One of the sensor leads supplies a five (5) volt
reference signal (sent by the ECA) to the resistor. The second lead is used to ground the resistor. The third lead is for the voltage signal to the ECA.
As the throttle plates move, the pivot arm moves along the curved resistor and receives a varying voltage signal. The ECA reads this signal and converts
it into throttle plate angle. The voltage signal ranges from approximately one (1) volt at idle to approximately five (5) volts at wide open throttle.
The TP sensor will also set a fault code if the ECA determines the output signal is out of the normal operating range.
