Cold Weather Automatic High Idle Problem

[jman]

Temp was 19 degrees the other morning and my truck was idling and it ramped to 1000 rpm like it is supposed to. Problem is it only stayed for about 30 seconds and it dropped back to 750 rpm. This has happened several times lately even with much lower outside temps. Do I have a bad sensor somewhere telling it it is warmer that it actually is? What sensors activate the high idle on an 03?



TIA

 

[RMalone]

I know coolant temp, together with intake air temp will trigger high idle. At 19deg on cold coolant my truck starts right into high idle, freaked me out first time it happened. I have seen mine cycle in and out of high idle but never after only 30sec of high idle. Anybody else have any ideas??

 

[DonFitzwater]

My automatic high idle is random at best. I had the dealer enable my high idle through the cruise buttons and it works great. The factory high idle is a joke and doesn't really run high enough r's to do you any good anyway. Take it to the dealer and have the enable your high idle.

 

[DPKetchum]

03 6 speed (or auto)there is no way to activate the ramp up idle through cruise etc. Its got what what its got.

 

[jman]

I'm just talking the automatic high idle. What all is involved in controlling this? It has to get its info from one or more sensors to automatically ramp up. I just wonder if I have a sensor that is off because at 19 degrees it should ramp up to 1000 and stay for a while or cycle up and down. Something is definitely out of whack here because it used to work like a charm.

 

[cerberusiam]

I'm just talking the automatic high idle. What all is involved in controlling this? It has to get its info from one or more sensors to automatically ramp up. I just wonder if I have a sensor that is off because at 19 degrees it should ramp up to 1000 and stay for a while or cycle up and down. Something is definitely out of whack here because it used to work like a charm.

IAT/MAP sensor provides the input for the idle ramp up. Clean it or replace it and see if that helps.



It is rumored that late 03 model trucks are flashable for the high idle with CC. It is supposed to be doable with acertain revision level in the ECU. Might try that route if you feel lucky.

 

[ddutil]

Misadjusted brake light switch? Dan

 

[PBrauer]

Oil pressure (low) can also activate the idle-up. When it's brief, that's usually what it is. Mine did it a few times even when it was warm... been meaning to check/clean the relief valve (probably stuck open a little).

 

[JBlakeman]

My 03 high idle does the same thing

I have a mid-year 03 that behaves the same. It's been pretty cold here in Wisconsin the last couple weeks and regardless of being plugged in or not, the high idle doesn't always act right. It can be sitting in 10 degree weather for two days and still start at 750, idle to 1000 for a minute or two, then back down to 750 the rest of time before I even get it in to drive.



But other times I could have driven it all day, stop in at a friends for ten minutes hot (coolant at 200) and it'll idle the entire time at 1000.

 

[jman]

Maybe it is a flame red sport package thing, JBlakeman. :-laf:-laf:-laf