Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove X2 from the PCB and the connector at the diverter valve
Disengage Diverter head to facilitate connector removal

Measurement:

Measure the resistance of each wire of the harness.
The resistance should conform to the table below:
WireResistance in Ohms
Blue - BlueContinuity (zero resistance)
Brown - Brown Continuity (zero resistance)
Black - BlackContinuity (zero resistance)
Blue - BlueContinuity (zero resistance)

Note.
For instructions to refit diverter valve actuator CLICK HERE