Set Appliance State:

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

Measurement:

Test 1:
Measure the resistance between red and purple.
Expect either approximately 8.3 kOhms or open circuit.
Test 2:
Measure the resistance between red and grey.
Expect either approximately 8.3 kOhms or open circuit.