It's because the design of the flapper type airflow meter makes a full range design unnecessary. Besides operating emissions, on a modern car the purpose of a TPS is to tell the ECU when the throttle plates open suddenly so that extra fuel can be injected to prevent a stumble.





the flapper design makes a full range TPS unnecessary, all OMP systems aside. It's a pretty impressive design for basically 70s technology.

http://bama.ua.edu/~darren/boschindex.html

original source is the Bosch L-Jetronic guide. Our fuel injection system (and especially s3 GSL-SE cars) are based on this system.

 

Interesting find man. Between this and your skills with INJ/ACCEL tip in on the PFC.......you could rule the world.

 

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What's the profile for an S5 TPS?

For the S4, I know the TPS output starts at about 1 volt at closed throttle and gets to about 5 volts at about 50% to 75% throttle.

 

full range TPS moves linearly from about .8 volts to 4.3 volts according to the s5 FSM . so max voltage is at WOT.

 

Yeah, and?

The S4 TPS is basically an "idle/off idle" switch. It is used for decel fuel cut and partially for the accelerator pump.