Does my hill decent function above 20 mph or not?

WARNING: Hill descent control cannot control descent in all surface conditions and circumstances, such as ice or extremely steep grades. Hill descent control is a driver assist system and cannot substitute for good judgment by the driver. Failure to do so may result in loss of vehicle control, crash or serious injury. Hill descent control can maintain vehicle speeds on downhill grades between 2 mph (3 km/h) and 12 mph (20 km/h). Above 20 mph (32 km/h), the system remains armed, but descent speed cannot be set or maintained. WARNING:Hill descent control does not provide hill hold at zero mph (0 km/h). When stopped, the parking brake must be applied and/or the vehicle must be placed in P (Park) or it may roll away. Hill descent control requires a cooling down interval after a period of sustained use. The amount of time that the feature can remain active before cooling varies with conditions. The system will provide a warning in the message center and a chime will sound when the system is about to disengage for cooling. At this time, manually apply the brakes as needed to maintain descent speed. Enabling hill descent control and setting the descent speed 1. Press and release the hill descent button located on the instrument panel. A light in the cluster will illuminate and chime will sound when this feature is activated. 2. To increase descent speed, press the accelerator pedal until the desired speed is reached. To decrease descent speed, press the brake pedal until the desired speed is reached. Whether accelerating or decelerating, once the desired descent speed is reached, remove your feet from the pedals and the chosen vehicle speed will be maintained. Note: Noise from the ABS pump motor may be observed during hill descent control operation. This is a normal characteristic of the ABS and should

 

Part of what you quoted:
"Hill descent control can maintain vehicle speeds on downhill grades between 2 mph (3 km/h) and 12 mph (20 km/h). Above 20 mph (32 km/h), the system remains armed, but descent speed cannot be set or maintained..."

So you can't use it as a downhill cruise control at highway speeds.

But it stays on and will kick in again at the low speeds which may or may not be desireable on a highway.

Doesn't your cruise control keep you at the set speed on downhills?

 

I don't like cruise control going up or down hill....
Shift pattern changes too much, and I want more control at these critical times while towing.

 

I'm not typing this to be snarky by any means but I think it is important to include things like vehicle year, make, model, engine, trans, and etc. so people know what they are dealing with when trying to give suggestions and/or advice. But also, you now say that you don't like that the shift patterns change while you are towing and you want "more control". I think this is information to know upfront to try to help you with a solution. But with this, I think it would be a good idea to give an overview of what it is you're wanting to accomplish as a whole so we have an idea.

Just my thoughts.

I have no idea what specific model of vehicle you have but assuming you have a pickup that is probably less than 10 years old, if you want to have "more control" over how much your vehicle slows down while going downhill with a trailer, then I would assume it would make sense to use the tow/haul button or function if your vehicle has that. I believe pretty much every pickup has something like this so I would think you could use that.

However, the other thing I was thinking is that if you have a diesel pickup, it "should" also have an engine brake option which would allow you to use that to help slow down your vehicle instead of using the brakes assuming that is what the goal is. But, again, with the exception of the internet sleuths that can pick apart what is typed and determine exactly what vehicle you have based on other things that you typed, how do we have any way to know that your vehicle has an engine brake option or is a diesel? Is your vehicle a 1/2, 3/4, 1 ton or larger pickup?

What is your overall goal or what is the specific problem? Is it that you feel unsafe when allowing your vehicle to slow down on its own with the current system in place or are there possibly malfunctions with the currect system? What type of trailer are you pulling and what type of cargo is on it? How heavy is the cargo? Just trying to get more details so there can be more/better help.

 

Yeah.... I was a little vague, sorry. Just for the record I have a 2011 6.2 SC FX4......... she is way more truck than what I need to pull my 7.5K loaded trailer and its 3K plus payload. I have since been able to figure what this feature is all about, which seems to be for more off road and descending hills at a slow, under 20 mph speed and not intended for highway travel as it won't allow my trailer brakes to function in that mode anyway.... sorry for ant confusion.

 

Well, as I believe I typed already, I was just trying to look at things from not just my perspective but others as well that might be wanting to help but "sort of" scratching their heads trying to decipher specifically what you have but also, what you're trying to accomplish. Which brings me to my question now.......after you have since come to terms with how the system works, what do you believe is going to be your solution going forward?

Again, what SPECIFICALLY are you wanting to do? Are you just wanting the vehicle to slow down by itself WITHOUT using your brakes while towing a trailer going downhill? If so, is this for ALL declines whether they be only very slight to mild grades or extreme grades? Also, at what speeds are you wanting this to happen? Say for example, you're wanting to go down the mountains around Colorado or something similar that has pretty steep grades, are you just wanting the vehicle to slow down the trailer and truck without using the brakes? If so, then I don't know why just using the tow/haul mode (I'm not sure if your model has that or if it's called that specifically but something to do with changing how the transmission reacts and/or shifts when you select this option/feature/button) wouldn't take care of this OR.....if you need to just simply downshift the gear selector, then just do that.

For me, I've got a 2002 F-250 with 6.8 and 4-speed auto with electronic 4x4. When I'm towing a trailer and want it to slow down WITHOUT using the brakes, I simply press the O/D button on the end of the shifter and it essentially downshifts from 4th gear (Overdrive) to 3rd gear. If this isn't enough because the grade is too steep or the trailer and cargo is too heavy, then I need to move the gear selector from "D" into "2" which would be 2nd gear. If that STILL ISN'T ENOUGH, then I need to be using my brakes as well. (I do use 1st gear as well when coming to stops or going down extremely steep declines or my trailer and cargo are really heavy though as well if needed)

I also have a 2005 F-350 SRW 6.0 (diesel) crew cab long box with electronic 4x4 and 5-speed auto. When towing, I don't use the tow/haul button on the end of the gear selector UNLESS I want to slow down. (Typically) I just tow with the tow/haul disengaged. I know some people could bawk at that and say that I'm gonna ruin my transmission that way by towing with it and letting it be in overdrive. However, I want the fuel mileage so I use the foot feed as needed if the load is too heavy for cruise or there are a lot of steep hills and so on. I do like the tow/haul for slowing down when coming up to stop signs or going down steep grades because when it's engaged, it not only takes it out of overdrive, but it also slows it down even more even though it's not actually downshifting. In my 02, it is either in 3rd gear if I have the O/D button depressed (light on/engaged) or, I have to manually select a different gear if I need it to slow down even more. With the 2005, it seems like it does a better job of slowing down even more than just taking it out of overdrive even without using the brake.

I suppose it's "almost like" (sort of ish) an engine brake in that regard even though not "technically" the same. Whatever the technology is, I prefer the way the 05 helps slow down without braking compared to my 02.

I don't think this was discussed and maybe it was a given but do you have a trailer brake controller built in (factory) or di you install one aftermarket? That would also definitely help assuming the trailer brakes are working properly.

But, if I'm understanding what you want to accomplish correctly or "assuming" how you want to do things, you just want the pickup to slow down WITHOUT having to use your brakes right? If so, is there a particular reason other than just simply not wanting to have to replace brake pads and rotors more often or getting your brakes too hot?

 

You are correct that the hill descent control is meant for off-road low speed situations and not for highway travel. If you are towing and wanting better speed control for downhill sections than the use of the tow/haul mode provides, I would suggest using the Manual shift mode. I have a 2015 F250 with the 6.2, CCSB 4x4 and I tow a fifth wheel that weighs about 8k throughout Colorado. The manual shift mode does an excellent job of holding the selected gear, but will not allow you to mechanically over-rev the engine by selecting too low of a gear. I have found that manually downshifting is an excellent way to manage speed on long downhill sections without overheating the brakes.

 

Here is how it all started..... I know a guy who is searching for his first full size truck. He asked about mine and he said he believed you need to get the FX4 to get hill decent as a standard and asked if mine had it. I wasn't sure because in all the years I had it I never used it, and the switch is more over by the passenger that in front of me......so, that was how it started. I read my manual and upon first reading didn't make sense. As to my pulling, stopping, using my tow/haul, trailer brakes/gain (factory installed) and cruise control and shifting or locking out gears in tranny..... I'm good and LOVE the way my truck handles its load.

 

Great....thanks. I have never felt the need to use that function yet, as I have always felt in control of my descending a grade and sparingly using my brakes. I have had to give them a little more foot to get it to downshift a few times, and I think next time I will try as you suggested. Also, when I travel, I will always only take those downgrades with good available day light.......it seems the older I get the more trouble I have at seeing in the darkness, especially in those dark mountainous areas and its harder for me to sense if I am going up, down, or what....... not chancing that while being pushed by a trailer.....nope!

 

Ok, I'm going to beg you not to read this as being rude, mean, or snarky in any way because that would serve no purpose but I'm now curious about the whole reason for why you're asking about the hill descent function now after the last part of your statement above. I you're genuinely "good" and "LOVE" the way your truck handles its load, then why are you trying to figure out how to use the hill descent function and asking about it in relation to slowing down when towing a trailer?

I'm not trying to argue here but just not understanding what the point is now if you are plenty happy (the way it sounds based on what you typed) with the way your vehicle performs/handles when towing a trailer and going down hills.

Hey, I'm all for doing something that can work better so if this is more a matter of just wondering if there is an even better way to do something, I'm all for it. I'll admit I used to be a person that just simply used their brakes more when going down hills while towing but finally understood that this is just not really safe and wears out brake pads/rotors and cooks the fluid more than necessary. If you can use the engine/trans to slow you down and you don't need to use the brakes at all or hardly at all, then that's a big win. I wish I had chose to do that sooner than I did in my life and it would have saved me more money. Oh well.

Again, I'm NOT trying to be rude and just trying to understand the thinking behind this. I "get" that if you never knew about a function that your vehicle had and all of a sudden discovered it that you would be curious to know how it functions. And if you read the manual and did what it explained and it didn't "seem" to operate the way that you think that it should be, then I totally get trying to get answers or maybe a better explanation. If that's all it was, so be it.

Yeah, nobody likes to have their trailer pushing them around especially down steep hills at night. Better to be more safe and travel when you feel comfortable. To each their own but for me, I prefer to travel at night due to a lot less traffic and almost no congestion in the larger metro areas or outskirts leading into them. I can't stand accidentally not realizing that you are running into rush hour or busy times. For some areas like going from the border of Oklahoma into Austin, Texas, it can "seem" like it's a never ending crap show with high amounts of traffic. Sadly, the majority of the interstate is only 2 lane which is stupid for an area with such a high population density but not only that, but the people on the roads just don't drive worth a crap. When you see a notification on your Google Maps that there is a vehicle stopped 2 miles ahead, it's like there has to be this 5 miles backup and go 10 mph and you get to the vehicle and it's just someone getting towed but meanwhile, everyone is traveling at a snail's pace and can't figure out to stop being "looky lou's" and just get their butts moving. I'll just stop with that rant now because it will never end.

 

My my my...... you ever try writing a book? LOL.
I have the luxury of traveling at my own pace, and I do. My issue with "darkness" is with dark areas in mountains and grades, not streets and highways with lighting, etc.
And finally, I will end my participation to the thread with this; "If I don't ask a question re: something I don't know, then I will always be ignorant in my thinking that I am right and above learning something new....."
Safe travels,.