I have a strange issue on my 2006 Flying Spur (Australian Delivered, RHD)

Only had the car a few weeks appeared fine a couple of weeks ago, however recently when I get in the car first thing in the morning it just doesn't like to go into "ignition mode", what would be considered position 2 on a normal car I guess, what I mean is that in acc position everything works, but I don't get any of the normal cluster lights / messages "press brake" etc when turning ignition. Note : the temperate has dropped here somewhat in the last few weeks

I just replaced both batteries thinking this could be related and not knowing the battery history, so know these are good

if I leave the key in the car and leave it alone it all comes good after a few minutes (5 - 15 minutes) after its started once I have never seen it happen on the same day again

When this occurs I get the following codes,-

01314 - Engine Control Module
004 - No Signal/Communication
01315 - Transmission Control Module
004 - No Signal/Communication
01299 - Diagnostic Interface for Data Bus (J533)
013 - Check DTC memory
01321 - Control Module for Airbags (J234)
004 - No Signal/Communication

And this one

001672 - ECM Power Relay Load Circuit
P0688 - 004 - Open Circuit

Once started and cleared, they don't come back until the next day when I try and start it

Should I start with the ECM relay ? Could it be going weak / sticky ? Is it just the - J271 - Motronic Engine Control Module (ECM) Power Supply Relay (167) in the right plenum fusebox, or is there more I should check / replace ?

Thanks in advance, hope someone can help. I don't have a name of an independent specialist near me at the moment, but looking for one also (Gold Coast, Australia) .

Andy