Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect plug from the pump

Measurement:

Check for continuity (zero resistance) between
the brown wire marked "D" at M4 on the PCB
to the corresponding pin at the pump plug.
Check for continuity (zero resistance) between
the blue wire marked "A" at M4 on the PCB
to the corresponding pin at the pump plug.
Inspect harness and connectors for good overall condition.