Radiator shutter

[BMac]

Hi all,
I have noticed that my radiator shutter is closed lately. I have not noticed it being open. The weather been cooler but only for the last few days.
I have also noticed that the mechanical indicator (dash) indicates a warm up to 90 degrees C where it stays as normal operating temp. The digital unit ( mdf device) indicates a apx 20 degree C lag, compared to mechanical device, during warm up. The digital unit also displayed 105 degrees C last night while highway driving and would not cool. Not that I look at this display a lot but I thought the digital display use to show similar readout as the mechanical unit.
How does the shutter work and what do the experts here thing about the conflicting readings. Local dealer will look at it when I take in for service next week or so. They stated that if there was a problem I would show a CEL.

Thanks guys

 

[BMac]

Just realized that the digital display is oil temp not coolant temp.

 

[meerschm]

The analog dial temperature indicator is driven by the computer, and does not directly tell you what the temperature reading is.

the computer makes it read straight up for a range of plus or minus 25 degrees or so.

this is true for all these cars, and for many more.

they do this so the dial is straight up for normal range of temperatures.