Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector X3 from the main PCB
Disconnect the harness from the diverter motor head

Measurement:

Measure the resistance between each of the pins on X3
and the diverter motor connector as listed below:
Connector X3Diverter valve Connector
Pin 46 (Brown) Pin 1
Pin 47 (Blue) Pin 2
Pin 45 (Black)Pin 3

Expect continuity / zero resistance on each test.
Also inspect the condition of the harness, visually
checking for any damaged insulation.