2013 Turbo Diesel 200 Series Entry System Failure

[Warmtone]

Apologies if this duplicates a previous post which seems to have vanished.
My 200 series Landcruiser has developed an Entry System fault with both FOB keys suddenly not recognised - even with new batteries. I have tried a cold reset removing main batteries but the fault remains. The car starts normally with the fob key pressed against the starter button with doors requiring the manual key.

I have tried scanning for faults but the Entry System shows no error codes.
However there is a communication issue which is puzzling:
I am using a Launch X431 (Toyota) scanner which seems to be incredibly competent at providing detailed analysis and active functions to make changes (bi- directional)

Here's the key findings from the diagnostic report:
Bcc Malfunction - OK
EFI/EV Code Receive - NG
EFI/EV Communication - NG
ID COde Difference - OK
ID Box Sleep Condition - No
Ignition available area - All
Lock request receive - NG
Lock/Unlock request - NG

Rolling Codes vehicle ID key status all measure OK.
I am trying to locate where the module is located that does the mediation between keys and main computer/door sensors
as I suspect a bad connection.

Can anyone help?

 

[bloc]

The service manuals and wiring diagrams I have access to are all US market, but things like location of components (adjusted for drive side) should be similar. I’m gonna watch this thread so I remember to dig in to the manuals when I have some time.. kindof an interesting problem.

I do remember someone posting with an immobilizer fault recently but can’t remember the specifics..

 

[Warmtone]

The service manuals and wiring diagrams I have access to are all US market, but things like location of components (adjusted for drive side) should be similar. I’m gonna watch this thread so I remember to dig in to the manuals when I have some time.. kindof an interesting problem.

I do remember someone posting with an immobilizer fault recently but can’t remember the specifics..

Thanks - appreciated!

 

[Boston Mangler]

May be apples to oranges but i had some odd issues with both my fobs and needing to press the start button directly by touching it with them

Even with new batteries

LONNNNNG story short, i had been using no name amazon cheapo batteries

I switched both fobs over to Duracell brand batteries and zero issues since.

May be totally unrelated, but my .02

 

[Warmtone]

May be apples to oranges but i had some odd issues with both my fobs and needing to press the start button directly by touching it with them

Even with new batteries

LONNNNNG story short, i had been using no name amazon cheapo batteries

I switched both fobs over to Duracell brand batteries and zero issues since.

May be totally unrelated, but my .02

Thanks for your response.
Batteries are high quality and verified by the scan tool - so unlikely to be a FOB issue.
The Scan gauge points to an internal communication issue between the main CPU and module that communicates with the key fobs.
I am trying to locate the above module as I suspect a possible loose connection.