[aerohead]

From a review of the Toyota Motor Sales, official Dealer Service training manual:
1) Toyota/LEXUS uses three (3) different throttle position sensors.
2) They are 'Linear-type' and 'On-Off type'.
3) They all possess Potentiometers.
4) They are all 'resistive' devices.
5) Inside the potentiometers are 'rheostats', with fractional portion division, vernier-scale, sliding-contact, variable-resistors, providing the dynamic ohm's law function for the variable-voltage signal to ECU TPS data terminal.
6) The TPS is responsible for signaling 'Driver Demand' ( driver intent ).
7) With feedback from the TPS, the ECU can perform precise, asynchonous EFI and Ignition timing optimization for optimum efficiency, power enrichment, as well as optimizations reflecting Oxygen-sensor A/F ratio, best torque, best stoichiometric, triple-catalyst emissions functions.
8) With feedback from the TPS, the ECU can optimize engine operation based upon thermistor coolant temperature-sensor data.