Cherokee 2WD L4-150 2.5L VIN H TBI (1988)
Throttle Position Sensor: Description and Operation
Throttle Position Sensor (TPS)-Manual Transmission
Throttle Position Sensor (TPS)-Automatic Transmission
This sensor is used to send input signals to the ECU to let it know the current angle of the throttle valve shaft. This sensor is a variable resistor that has a
5 volt reference signal applied to it by the ECU. The TPS sends signals back to the ECU in the range of 1 to 5 volts. The ECU uses these input voltage
signals to determine the current position of the throttle.
An input voltage level of 1 volt indicates a minimum throttle opening or idle condition. An input voltage of approximately 5 volts would indicate a
maximum throttle opening or wide open throttle condition.
Two different sensors are available, one is used on vehicles with automatic transmissions and the other is used on vehicles with manual transmissions.
The TPS used with automatic transmissions has two integral wire harness electrical connectors, one three pin connector and one four pin connector, that
plug into the engine wire harness. The three pin connector supplies input to the Transmission Control Unit while the four pin connector supplies input to
the ECU. The wire harness for the manual transmission TPS is not an integral type, it connects directly to the engine wire harness connector.
