Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect the main multi-pin connector from the gas valve

Measurement:

Test 1:
Measure the resistance between pins V1 and V2.
Expected readings should be approx. as per table below.
Test 2:
Measure the resistance between any pin on V1 or V2 to
the earth point (centre pin)
Expected resistance greater than 1 Mohm.