High idle not working

[Bearman95]

I have a 2021 Limited longhorn crew cab 2500, 6.7 Cummins and I cannot seem to get the high idle working. Truck is in park, parking brake is on. After starting the truck I press the cruise control button and then press set. I have tried this numerous times and it will not work on my truck. Any ideas?

 

[Papa_smurf]

I have a 2021 Limited longhorn crew cab 2500, 6.7 Cummins and I cannot seem to get the high idle working. Truck is in park, parking brake is on. After starting the truck I press the cruise control button and then press set. I have tried this numerous times and it will not work on my truck. Any ideas?

After pressing (set -) then you pres the (res +) button till the rpms get the level you want them at. Are you pressing the (res +) to raise the rpms after pressing (set -)?

 

[Bearman95]

Yes I pressed resume which is a positive button. Just curious if the 21s have that high idle setting. Because mine sure doesn’t. I pressed cruise control on, then set which should have raise the idle all by itself. Then I pressed resume/positive. No luck.

 

[Will_T]

Just curious if the 21s have that high idle setting.

I have a 2021 Laramie 3500 and high idle works for me.

 

[Brutal_HO]

Yes I pressed resume which is a positive button. Just curious if the 21s have that high idle setting. Because mine sure doesn’t. I pressed cruise control on, then set which should have raise the idle all by itself. Then I pressed resume/positive. No luck.

Press Cruise, then you press the Set - first for initial idle up.

You press the Set + button to increase the idle up to 1500RPM.

Brake pedal or cancel button to cancel. I think if you press ACC if you have it will also cancel idle.

 

[H3LZSN1P3R]

Take the parking brake off maybe?

 

[Brutal_HO]

Take the parking brake off maybe?

Doesn't matter on mine. I always use the parking brake.

 

[Bearman95]

OK I finally got it to working, apparently it will not work when the engine is cold. After about a 30 mile trip I parked in my driveway and put it in park, parking brake on, press cruise control, then press the set button and everything worked as it should. First time I’ve ever gotten it to work But the other two or three times that I have tried it the engine was cold and was not up to operating temperature. Seems like it should work when the motor is cold so it will warm up faster but not on my truck.

 

[Will_T]

OK I finally got it to working, apparently it will not work when the engine is cold. Seems like it should work when the motor is cold so it will warm up faster but not on my truck.

Mine does. That is often when I use it.

 

[Brutal_HO]

If you have the latest software flash, it WILL limit the high idle max RPM when cold (I think below 0F?)

What drives me nuts is that it won't work after a certain number of miles, which I have yet to really determine, unless you shut the truck off and restart.

 

[Bearman95]

Thanks guys I think it was driver error all along. When I start my truck of course I have to put my foot on the brake and I think I was leaving it on the break when I was trying to start a high idle when The motor was still cold – but having my foot on the brake the truck would not go into high idle.

 

[RedRam]

If you have your foot on the brake pedal it won’t work. Don't ask how I know.

 

[H3LZSN1P3R]

If you have the latest software flash, it WILL limit the high idle max RPM when cold (I think below 0F?)

What drives me nuts is that it won't work after a certain number of miles, which I have yet to really determine, unless you shut the truck off and restart.

Any idea if there is a time limit? I was running the truck to charge my battery in the flat deck after winching logs on the trailer and after a while it seemed to kick the high idle out, never looked in to it though

 

[Brutal_HO]

Any idea if there is a time limit? I was running the truck to charge my battery in the flat deck after winching logs on the trailer and after a while it seemed to kick the high idle out, never looked in to it though

Could be time instead of miles I suppose.

 

[elephantrider]

if there's a timer, it's more than 30 minutes.

 

[H3LZSN1P3R]

if there's a timer, it's more than 30 minutes.

Hmm it was less that that i wonder if the draw from the winch played a part

 

[elephantrider]

that's as far as I've high idled it. was pretty dang cold where I was that day.

 

[Myfast70]

Thanks guys I think it was driver error all along. When I start my truck of course I have to put my foot on the brake and I think I was leaving it on the break when I was trying to start a high idle when The motor was still cold – but having my foot on the brake the truck would not go into high idle.

Here you guys go! This is from the '22 manual

 

[Brutal_HO]

The process has already been clarified.

It's the cutoff timing that's being discussed.

That's not in the manual.

 

[AEV_CUMMINS]

Thank you for posting this! I have been under the impression that only HO 3500's have the idle up feature and I have not even tried, when there have been times I have wanted to. I am running out to the truck to give it a shot now!