Butterfly valve position potentiometer

BUTTERFLY VALVE POSITION POTENTIOMETER

The arrowed screw is used to adjust throttle closure to prevent fouling against the surrounding duct; this screw must not be used to adjust idle speed because it is set by flushing during manufacture and should never be tampered with under any circumstances.

The resistance value measured across terminals 1 and 2 must be > 3KΩ

Butterfly valve percentage opening sensor (A) is fitted on butterfly valve case (B) and connected directly to the butterfly valve spindle.

Butterfly valve angular position is determined by measuring the resistance of the potentiometer that constitutes the sensor (resistance varies as throttle opening angle changes).

The ECU provides the butterfly valve position sensor with a reference voltage of 5 Volt.

As rotation of the butterfly valve about its spindle changes, electric circuit resistance alters: by measuring the voltage between one resistance terminal and variable connection of potentiometer (3) connected to terminal F5, the ECU is able to determine percentage throttle opening on a parametric basis.

If throttle opening is 30°, therefore, the ECU measures a voltage of 1.70 Volt.

Pin 1 is connected to pin F8 of the control unit and receives a signal, while pin 2 is connected to pin F15 of the ECU and to earth.