Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove the 4 wire pump connector from the PCB
Disconnect the electrical connection from the pump assembly

Measurement:

Test 1.
Measure the resistance between pin 2 on the pump
connector and pin 1 on the 4 wire PCB connector.
Test 2.
Measure the resistance between pin 3 on the pump
connector and pin 2 on the 4 wire PCB connector.
Test 3.
Measure the resistance between pin 4 on the pump
connector and pin 3 on the 4 wire PCB connector.
Test 4.
Measure the resistance between pin 1 on the pump
connector and pin 4 on the 4 wire PCB connector.
Expect continuity / zero resistance on each test.
Also visually inspect the condition of the harness.