Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect connector X2 from the PCB
Measurement:
Inspect the condition of the harness between the gas valve modureg and the PCB.
Check for continuity between the grey wire (pin 8) at X2 connector to the grey wire at the modureg and also the yellow wire (pin 9) at X2 connector to the yellow wire at the modureg.
Check for continuity between the grey wire (pin 8) at X2 connector to the grey wire at the modureg and also the yellow wire (pin 9) at X2 connector to the yellow wire at the modureg.
Isolate as per TOPs P4
and refit as necessary