They have the temp sensors.
The way they set the system is now if it is below like 40 or above 75, the idle will not count against you. Or is not supposed too lol.
And the truck will run. In the area between you have to push in the clutch when the light comes on and it will keep running on the cummins trucks. On the prostar plus trucks it is hit or miss. Most of the time it will, sometimes it will not. Not allot of need to idle between 50 and 70 anyway.