Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove the 7 pin connector from the PCB
Remove the connector from the diverter valve

Measurement:

Measure the resistance between the points listed below:
Pin 3 on the PCB connector to pin 5 on the diverter valve connector.
Pin 5 on the PCB connector to pin 6 on the diverter valve connector.
Pin 6 on the PCB connector to pin 4 on the diverter valve connector.
Expect continuity / zero resistance on each wire in the harness.
Also visually inspect the condition of the harness through its length.
Are the harness checks satisfactory?