[MrMCar]

I'm stretching hard to offer an answer. However usually when air pocket, there's steam in the head and temperatures skyrocket very fast...

 

[MrMCar]

Good thoughts about a hyperactive fan, albeit if the thermostat is working correctly..... The engine stays up to proper temperature and the radiator is excessively cool.

The thermostats job is not to keep the engine cool, rather to hold it within a certain delta.

Waiting to hear back about the connection and if the thermostat is being driven open by the DME?

 

[MrMCar]

I think you mean "activation"?
I'm not aware of a "Fan Test".

 

[MrMCar]

INPA allows you to specify an electric fan speed for testing.

Let me be a little more clear.
In the GT-1 or ISTA there are "Test Plans" that take you through modules, step by step to arrive at a conclusion.

What Sapote and you describe is not a Test Plan, rather a command or activation.