Jeep Wagoneer/Commando/Cherokee 1984-1998

Throttle Position Sensor (TPS)



See Figure 1

The throttle position sensor is mounted on the throttle plate assembly and provides the ECU with an input signal of up to 5 volts to indicate throttle position. At minimum throttle opening (idle speed), a signal input of approximately 1 volt is transmitted to the ECU. As the throttle opening increases, voltage increases to a maximum of approximately 5 volts at the wide open throttle position.

A dual TPS is used on models equipped with automatic transmission. This dual TPS not only provides the ECU with input voltages, but also supplies the Transmission Control Unit (TCU) with an input of throttle position.

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Fig. Fig. 1: Throttle position switch (A) used on vehicles with manual transmissions and (B) used on vehicles with automatic transmissions


  1. Unplug the connector at the TPS.
  3. Check the voltage between the black and grey wires with the key ON . Voltage should be approximately 5 volts. If the proper voltage is not present, check the harness for shorts or opens.
  5. Engage the wire connector to the TPS. With the key ON , and the throttle plate closed, check the voltage between the blue and the black wires. Voltage should be approximately 0.8 volts.
  7. If voltage is not correct, loosen the screws securing the TPS and adjust until 0.8 volts is present.
  9. If adjusting does not bring sensor voltage to specification, replace the TPS.