Open Loop/Closed Loop

[JockoT]

I was aware that DFCO doesn't come into effect until the engine is sufficiently warmed up and thought it was a function of the Open Loop/Closed Loop. This morning I set the ScanGauge up to show me Coolant Temperature and Loop ststus, with a view to finding out at what temperature the changeover occurred, but almost from the get go the system was cycling between Open and Closed Loop. This happened even before Blue dashboard Engine Temp light went out.
I take it there is more in play than I first though?