Set Appliance State:

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

Measurement:

Measure for continuity (zero resistance) between each of the 5 wires, in turn, running from the X13 (rightmost blue and brown) and X11 (black and grey) to the pump.
Inspect the harness and connectors for good overall condition.
NOTE:
The fifth wire in the pump harness is an earth which terminates at the main earthing strip to the left of the PCB.