High Idle Option function Gas and Diesel Heavy Duty trucks

sheath · July 6, 2022

Ordered the High Idle Option with the L8T. Trying to figure out how to make it work, and couldn't find anything in the Owner's Manual in this regard. So I did a Google search, and found this excellent video that explains how to activate the function.

Basically the steps are:

* Engine Running

* Transmission in Park

* Parking Brake set

* Select the "Set" function of the Cruise control

This increases idle speed to approximately 1,200rpm.

To turn off the high idle, select the Set function, Cancel function or step on the foot brake.

Hope this is helpful.

https://www.youtube.com/watch?v=xxovWkmGFiI&ab_channel=FamilyAdventures

ETA: This is an optional feature, not standard. So if you try this and it doesn't work, you may not have the option. It may be something a dealer can initialize though, since it is all software.

Edited July 6, 2022 by sheath

pokismoki · July 7, 2022

isnt it located in the infotainment system?

Another JR · July 7, 2022

Foot has to be OFF the brake pedal when you hit set.

clearlysurfing · July 7, 2022

5 hours ago, sheath said:

Ordered the High Idle Option with the L8T. Trying to figure out how to make it work, and couldn't find anything in the Owner's Manual in this regard. So I did a Google search, and found this excellent video that explains how to activate the function.

Basically the steps are:

* Engine Running

* Transmission in Park

* Parking Brake set

* Select the "Set" function of the Cruise control

This increases idle speed to approximately 1,200rpm.

To turn off the high idle, select the Set function, Cancel function or step on the foot brake.

Hope this is helpful.

https://www.youtube.com/watch?v=xxovWkmGFiI&ab_channel=FamilyAdventures

ETA: This is an optional feature, not standard. So if you try this and it doesn't work, you may not have the option. It may be something a dealer can initialize though, since it is all software.

The brake pedal must be off when you press the set button

foodle

sheath · July 7, 2022

14 hours ago, pokismoki said:

isnt it located in the infotainment system?

I haven't looked. If you find it there, please post up. The video and my explanation works though.

9 hours ago, clearlysurfing said:

The brake pedal must be off when you press the set button

foodle

Yes, since the foot brake cancels the function, stepping on it would not allow it to set.

Another JR · July 7, 2022

I’m pretty sure you can’t control it from the infotainment system.

Flatus · July 7, 2022

What is this purpose of this?

Another JR · July 7, 2022

Increases alternator output and increases cycle pressures and temperatures, which makes the extended running easier on the engine.

sheath · July 8, 2022

14 hours ago, Flatus said:

What is this purpose of this?

I added the option for three reasons.

* Increase alternator output when I'm working the winch to clear brush and trees, repairing fence line, etc.

* Increase AC compressor rpm so that it cools better in the cab during extended idle times.

* Spend more money on gas, because the oil companies aren't making enough off me already.

Flatus · July 8, 2022

6 hours ago, sheath said:

I added the option for three reasons.

* Increase alternator output when I'm working the winch to clear brush and trees, repairing fence line, etc.

* Increase AC compressor rpm so that it cools better in the cab during extended idle times.

* Spend more money on gas, because the oil companies aren't making enough off me already.

Does having that option bypass (turn off) the factory 15 min idle shut off? If so, that would be nice.

sheath · July 8, 2022

I haven't let it run for more than 15 minutes yet without moving the truck, so I can't tell you. The 15 minute shut off can be deactivated by the dealership service department though. I plan on having that done at the next service.

Another JR · July 8, 2022

The 15 minute shutoff is after a remote start if you don’t do the steps to extend it. If the car is actually on, the shutdown time is longer, but I can’t remember exactly how long and didn’t find it immediately in the manual.

sheath · July 8, 2022

I think if the engine is running, and the key fob is used to lock the doors the engine will run for 30 minutes. I can't find this in the Owner's Manual. This can be turned off by the dealership service department (there is a thread on this forum discussing this).

If you remote start it is 15 minutes, with up to 30 minutes if remote start function is pushed again (page 21 of Owners Manual).

Random · July 11, 2022

Curious, does the engine still shut off after 30 minutes when the high/fast idle is activated? I've read the manual, but it doesn't provide any details outside of operating the high idle function. I'm considering having the feature added to my truck at the dealer, but having the engine shut off would be a deal breaker.

Another JR · July 11, 2022

From what I recall reading, the shutoff function operates regardless of whether you are in normal or high idle. Sheath says the dealer can turn off the auto shutoff. You can also defeat the auto shutoff at normal idle by running in neutral, but I don’t like the idea of that. I don’t believe you can use high idle in neutral.