Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Appliance drained and discharged
Remove the low pressure sensor from the pump manifold (see note)
Note.
If the right side panel can be partially removed then the water pressure sensor can be removed separately, but if side access is difficult then the pump, manifold and low pressure sensor will need to be removed complete

Observation:

Inspect the low pressure sensor and the pump manifold
for any blockages in the waterways.
Are there any blockages present ?