Set Appliance State:

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

Measurement:

Measure the resistance between each of the pins on CN9
and the diverter motor connector as listed below:
Connector CN9Diverter valve Connector
Pin 20 (Brown) Pin 1
Pin 18 (Blue) Pin 2
Pin 19 (Black)Pin 3

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