Throttle Position Sensor: Description and Operation

Throttle Position Sensor Operation:

PURPOSE
This sensor is used to send input signals to the Powertrain Control Module (PCM) to indicate the current angle of the throttle blade.

THEORY/OPERATION
This sensor is a variable resistor that has a 5 volt reference signal applied to it by the PCM. The Throttle Position Sensor (TPS) sends signals back to the PCM in the range of approximately 1 to 4 volts, depending upon the throttle shaft angle. The PCM uses these input voltages to determine the current position of the throttle.

The PCM uses the voltage signals from the TPS and other input sensors to determine the proper air/fuel mixture and ignition timing for certain operating conditions. Some of these operating conditions are: acceleration, deceleration, idle, and wide open throttle.

TYPICAL READINGS
An input voltage of approximately 1 volt indicates a minimum throttle opening, idle, or deceleration condition. An input voltage of approximately 2 volts indicates a cruise or light acceleration condition. An input voltage of approximately 4 volts would indicate a maximum throttle opening or wide open throttle condition.

CIRCUIT OPERATION
From the Powertrain Control Module (PCM), circuit K6 supplies 5 volts to the Throttle Position Sensor (TPS). Circuit K6 connects to cavity 6 of the PCM.

Circuit K22 delivers the TPS signal to the PCM. Circuit K22 connects to cavity 22 of the PCM.

The PCM provides a ground for the throttle position sensor signal (circuit K22) through circuit K4. Circuit K4 connects to cavity 4 of the PCM.