1994 Toyota/LEXUS throttle position sensors

[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.

[freebeard]

Shouldn't this be in instrumentation? Oh, right.... throttle-stop.

[redpoint5]

I'm not following this thread logic. It simply states how a throttle sensor functions. Modern cars have throttle by wire too, not just a position sensor. The throttle is controlled via a motor.

[me and my metro]

1994 is pretty early for drive by wire. Ford and Gm went drive by wire about 2003. Of course the Diesels were drive by wire in 94.

[aerohead]

Originally Posted by redpoint5

I'm not following this thread logic. It simply states how a throttle sensor functions. Modern cars have throttle by wire too, not just a position sensor. The throttle is controlled via a motor.

1) I was 'attacked' for using 'rheostat' in the same sentence as 'potentiometer.'
The information provided was to illustrate the state-of-the art for Toyota electronic engine management, as of 1994; which I'm operating.
2) The second point had to do with the implication for 'constant torque' within the context of an electronic engine management system, robbed of its vision. The cautionary tale, elaborated on in Sovran's SAE Paper on constant-throttle testing.