Set Appliance State:
Set Multimeter to Resistance 
Isolate Mains Power to appliance as per TOPs P4
Disconnect connector plug CN2 from the Sequence Control PCB
Remove Air Pressure Switch Tubes from Air Pressure Switch
Disconnect connector plug CN2 from the Sequence Control PCB
Remove Air Pressure Switch Tubes from Air Pressure Switch
Measurement:
Measure the resistance between connection L2 (White wire) and connection L3 (Brown wire) at the disconnected plug.
Note 1:
Measurement taken at disconnected plug not PCB.
Note 2:
On some models sequence control PCB may only have numbered connections in which case connections will be numbered 5, 6 & 7. Test to be carried out on Brown and White wires on the plug that were connected to connections 5 and 6.
Note 1:
Measurement taken at disconnected plug not PCB.
Note 2:
On some models sequence control PCB may only have numbered connections in which case connections will be numbered 5, 6 & 7. Test to be carried out on Brown and White wires on the plug that were connected to connections 5 and 6.
Isolate as per TOPs P4
and refit as necessary