Throttle Position Sensor: Description and Operation

PURPOSE
PCM uses sensor input with other inputs to determine current operating conditions.

PCM adjusts air/fuel mixture (injector pulse width) and ignition timing.

OPERATION
The TPS connects to the throttle blade shaft The TPS is a variable resistor that provides the Powertrain Control Module (PCM) with an input signal (voltage).
- The signal represents throttle blade position.
- As the position of the throttle blade changes, the resistance of the TPS changes.

The PCM supplies approximately 5 volts to the TPS. The TPS output voltage (input signal to the powertrain control module) represents throttle blade position. The TPS output voltage to the PCM varies from approximately 0.40 volt at minimum throttle opening (idle) to a maximum of 3.80 volts at wide open throttle.

The TPS mounts to the side of the throttle body.

CIRCUIT OPERATION
From the Powertrain Control Module (PCM), circuit KS supplies 5 volts to the Throttle Position Sensor (TPS). Circuit KS connects to cavity 61 of the PCM.

Circuit K22 delivers the TPS signal to the PCM. Circuit K22 connects to cavity 35 of the PCM. On vehicle~ equipped with an electronically controlled automatic transaxle, circuit K22 splices to the Transmission Control Module (TCM).

The PCM provides ground for the TPS signal (circuit K22) through circuit K4. Circuit K4 connects to cavity 43 of the PCM.

Helpful Information
Circuit KS splices to supply 5 volts to the manifold absolute pressure sensor and NC pressure switch.

Circuit K4 also splices to supply ground for the signals from the following:
- Upstream heated oxygen sensor
- Downstream heated oxygen sensor
- Camshaft position sensor
- Crankshaft position sensor
- Engine coolant temperature sensor
- Manifold absolute pressure sensor
- Knock sensor
- Intake air temperature sensor
- Vehicle speed sensor