High-Idle mode is independent of ECT!

[rbattelle]

I noticed this yesterday, and don't recall anyone else pointing this out before. High idle mode is apparently not a function of engine coolant temperature. After a long highway drive I was sitting in the truck (with it idling) waiting for the wife to come out mof the store. After 2 minutes sitting there, the engine went to high idle. Note I never shut the truck off... we pulled in, she got out and went inside, and I sat there idling. Conditions were as follows:



Ambient temperature: 27*F

Engine Coolant Temp: 187*F

Intake air temperature: 57-59*F



I was pleasantly surprised. I believe it's a function of intake air temperature only.

 

[XcumminsX]

was your truck fully warmed up... . if you sit at idle doing nothing for about 1 minute and the truck isnt warmed up it will kick on.

 

[JNutter]

I've noticed the same thing, even when the truck is fully warmed up.



If I've been towing one of my Jeeps or my skid loader somewhere and I get out with the truck running (to look for a good spot to unload), the truck will often kick into high idle before I get back in.

 

[rbattelle]

X,



Truck was completely warmed (notice ECT=187*F). I had just pulled off the highway after 45 minutes at 70 mph.

 

[lschultz]

I have read where they are suppose to do this. One of them sensors sensed something was out of speck,probably intake air temp at idle.

 

[XcumminsX]

hmm, thats pretty cool and a good idea. I havent noticed it yet i havent driven anywhere real far to where i pull over in a truck stop or something.

 

[Tony T.]

I believe I read in the manual if temp is under 32*F that it will kick into the high idle mode as long as the coolant temperture is under 190*F. Page # 187 2003 Owners Manual under Engine Idling-Cold Weather section, look under Note:

 

[ScottBrown]

Your trucjk is fine, It is doing what it is supposed to do. I live in Alaska. and when the temp is below freezing 32f and colder, it will up the idle to 1000rpm. This will happen after aprox 2 min. Does not matter if I have been driving 3 hours. it will go up after 2 min. Look at this as a good thing.

 

[bulabula]

Mine's done the same thing for the last 2 winters. I think its a good thing.

 

[dieselpilot1969]

don't guess i'll be worrying about that, it was like 72* here in dallas today