How in the world freaking cold is to get it to 3 cylinder idle???? I thought that was only below 0*F???? I have actually never seen one do the 3 cylinder idle, only heard of it down here in TX it rarely gets into the single digits.
There is a big difference in the automatic idle increase and the actual high idle function. The manual control is "Cruise ON" then "SET" goes to 1100 and using the "Accel" and "Decel" buttons increase up to 1500 incrementally and back to 1100 also incrementally. The automatic function only occurs when temps are low enough to need it to get warmed up.
Also, the manual control is not set "ON" by the factory, it has to be turned on either by a dealer's computer or by a tuner function while the automatic control is there all the time. Auto trans trucks just need to be enabled and the manual trans trucks are supposed to have a clutch safety switch- it's just a switch that sends a ground to the ECM when the clutch is fully released and goes away when you touch the clutch, most of US just bypass that by sending the ground all the time, the manual high idle disables when speed reaches 3MPH anyhow- I know, I tried to use it to drive.....just for fun.