The pedal position sensors work in the same way as the throttle position
sensors. They need 5V and ground from the controller and provide PPS1 and PPS2
position signals. It is important that the PPS1 signal increases when pressing
the pedal!
If PPS2 is not connected, the system will still work but with reduced
reliability. If the only pedal position sensor (PPS1) is faulty or a wire gets
disconnected the throttle valve could open. The Throttle controller will check
for this second pedal position sensor during first calibration and use it if
available.