Towing down hill?

[Todd78d]

I have a 2018 2500 with the 6.4 Hemi and automatic trans.
While towing me 25’ camping trailer It’s a light weight made for 1/2 ton to pull it. I’m having to step on the throttle while going down hill unless it’s pretty steep. When not pulling a trailer on level ground it’s like shifting to neutral when let off the gas as it goes Into ECO.
Does anybody know what would cause this?

 

[smurfs_of_war]

I have a 2018 2500 with the 6.4 Hemi and automatic trans.
While towing me 25’ camping trailer It’s a light weight made for 1/2 ton to pull it. I’m having to step on the throttle while going down hill unless it’s pretty steep. When not pulling a trailer on level ground it’s like shifting to neutral when let off the gas as it goes Into ECO.
Does anybody know what would cause this?

That sounds like the fuel shutoff technology they have. Don't remember what they call it or exactly how it works, but when you let off the throttle to coast a bit it shuts down the fuel delivery somehow.

Just a guess. Mine does it too.

 

[Princeton_Man]

Sounds like Hill Decent Control. Don't know if you can turn off or not.

 

[62Blazer]

Hill Descent Control only works to like 5 mph, and having to hit the accelerator going downhill has nothing to do with any fuel shutoff.

If you have the tow/haul mode activated it will use the compression of the engine to try to keep the vehicle speed down. It changes some various parameters to help maintain speed going downhill without riding the brakes non-stop. It's probably downshifting and/or keeping the converter locked up versus just free-wheeling. My suggestion is if you are in tow/haul to try driving in the same situation without the mode on and see how it does.

 

[indept]

The 4th gens do cut off fuel when coasting.

 

[Todd78d]

Thanks for all the reply’s. I only use tow haul when in steep hills.

 

[JC5Cents]

Trailer brakes are rubbing?

 

[Tim7139]

I've had that happen with the factory brake controller in a gas 2500, and was able to override by taking off Tow/Haul and manually shifting into 6th.

There are a few threads that discus, and have heard the Fast Lane Truck guys mention it in towing torture test, but I've not seen one name of the function.
https://www.ramforum.com/threads/cruise-control-towing-downhill.137911/

 

[392DevilDog]

I have a 2018 2500 with the 6.4 Hemi and automatic trans.
While towing me 25’ camping trailer It’s a light weight made for 1/2 ton to pull it. I’m having to step on the throttle while going down hill unless it’s pretty steep. When not pulling a trailer on level ground it’s like shifting to neutral when let off the gas as it goes Into ECO.
Does anybody know what would cause this?

Let me try to understand this question.

When towing with your trailer...you have to apply throttle to go down. Meaning...it will not just coast down the hill. If that is what you mean then the truck is working as designed. When you plug in the trailer the truck knows it needs to hold a gear longer and will engine brake more.

When going down the hill with out a trailer...it coasts well and even goes into MDS.
Again. The truck working as designed. It knows you need no input from the accelerator and need no extra power. It knows the truck brakes are plenty to stop it at this speed.

So if that is what you meant...that with a trailer it goes down the hill with need for acceleration to go faster and when going down the hill empty it coasts fine...then your truck is fine.

Take the truck to that hill empty with tow haul selected and it will act like it does with the trailer.

If I read your post right.

Using text is sometimes very hard to get a point across

 

[crazykid1994]

Does the trailer have manual brakes or electronic brakes? The surge brakes may be pressing if you are going downhill if the trailer is pushing into the truck.

 

[pacofortacos]

Could just be engine/wind resistance combined with decel fuel shutoff. Mine will do that even in normal mode with no trailer at highway speeds. 1500 with 3.92's