Prizm L4-1600cc Throttle Position Sensor Locations
Throttle Position Sensor: Description and Operation
Throttle Position Sensor
The Throttle Position Sensor (TPS) consists of a contact point (idle switch) and a potentiometer. The TPS is connected to the throttle valve shaft on the
throttle body, and detects the throttle valve opening. The throttle opening in the idle state is detected by means of the idle switch which supplies B+ to
the ECM when the throttle is moved off idle. The full opening is detected by the potentiometer. A 5-volt reference voltage is applied to the sensor from
the ECM and the resistance varies according to the throttle valve opening, the output voltage varies accordingly. By monitoring the sensor output
voltage, the ECM detects the throttle valve opening and its change.
