Throttle Position Sensor: Description and Operation

Throttle Position Sensor (TPS)/Automatic Idle Speed (AIS) Motor:

This sensor is used to send input signals to the engine controller to let it know the current angle of the throttle blade. This sensor is a variable resistor that has a 5 volt reference signal applied to it by the engine controller. The Throttle Position Sensor (TPS) sends signals back to the engine controller in the range of 1 to 5 volts. The engine controller 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.

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