In the service manual, F09 refers to the pressure switch (pressostat).
In fact, the causes may be all that can fool the control unit.
To fix F09, the unit must be inspected by someone who has the minimum knowledge of how the washing machines work.
Whoever claims this error must be willing to investigate and provide the required details.
This error code means there is an abnormality.
If the on-off door lock LED on a Whirlpool washer flashes rapidly at the same time as at least one other LED, then this means there is an abnormality.
Try first to reset the machine. You can press and hold the reset button for a couple of seconds, otherwise turn off the power completely (unplug it) for 5 mins.
If your machine is reasonably old, perhaps take a look at the bushes of the motor . Before that, take the manual and run the test cycles by following the instructions; it might provide you with answers
If after 30 seconds the control does not detect water entering
machine, the valves will be turned off and the error code will be
displayed. OR If the control has turned the water valves on and after
8 minutes the flow sensor has detected 10.5 gallons of water passing
through it, but has not detected the pressure switch trip, the valves will
be turned off and the error code will flash.
Press PAUSE/CANCEL twice to clear the display.
check the fill hose screens or you my have to repalce water valve make sure water is turned on....