Set Appliance State:

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

Measurement:

Measure the resistance across terminals marked V1 (bottom 2). Resistance should be approximately 2.8 kOhms.
Measure the resistance across terminals marked V2 (top 2 connections). Resistance should be approximately 1.6 kOhms.
Reconnect plug after test.