2017+ Ford Platinum trucks with adaptive cruise control and exhaust brake

[SNOKING]

There is a tread going on the RV.net tow vehicle forum about this regarding new Fords with adaptive cruise control. Seems that even when cruise control is in normal mode and not adaptive the truck is using it's service brakes in conjunction with the exhaust brake when descending a grade. This could lead to over heated service and trailer brakes.

https://forums.goodsamclub.com/index.cfm/fuseaction/thread/tid/29640916/srt/pa/pging/1/page/1.cfm

 

[MCTalley]

Interesting.

On my '16, I kick the cruise control off at the top of the hill (if it is even still on - I generally like to keep my own foot in it at my pace). Descending big hills with my house behind me I'd rather be in full control. I turn off cruise, drop mine in Manual shift mode and drop down to an appropriate gear for the descent. If one gear is a little too slow and the next one a bit too fast, I'll toggle between the two as needed to maintain the approximate speed I'm looking for.

I will say, aside from the behavior noted in that thread, that adaptive cruise would be great in some non-hilly situations when I get behind a truck or slower car that is going just under my set speed and is varying in speed.

 

[dave10a]

In flat country I set the cruise to 62mph in 6th gear and enjoy the scenery. In hilly/mountainous roads I generally go to manual mode and take complete control. However, for long and steep up-hill grades I will find the gear that allows 2000/2500 rpm and set the cruise control and enjoy the long grade and scenery. That keeps the engine and transmission working the least to allow the best operating economy and temperature. I come to appreciate Fords flat torque curve.

 

[SNOKING]

Interesting.

On my '16, I kick the cruise control off at the top of the hill (if it is even still on - I generally like to keep my own foot in it at my pace). Descending big hills with my house behind me I'd rather be in full control. I turn off cruise, drop mine in Manual shift mode and drop down to an appropriate gear for the descent. If one gear is a little too slow and the next one a bit too fast, I'll toggle between the two as needed to maintain the approximate speed I'm looking for.

I will say, aside from the behavior noted in that thread, that adaptive cruise would be great in some non-hilly situations when I get behind a truck or slower car that is going just under my set speed and is varying in speed.

Having the service brakes involve in Adaptive mode is understandable, however having them assisting the slowly of the TV/trailer on a grade in normal mode seems to be the issue. This becomes a driver training issue that some my not even realize until they have overheated their service brakes.

 

[LBR]

Having the service brakes involve in Adaptive mode is understandable, however having them assisting the slowly of the TV/trailer on a grade in normal mode seems to be the issue. This becomes a driver training issue that some my not even realize until they have overheated their service brakes.

I've never taken our cruise control out of adaptive mode yet...will experiment with it next time I have a chance.

If it was a known issue during the 2017 build year, ours MAY not have that trait. Our truck was built close to the last day 2017s were being built and a few days later the 2018 s were getting built.

 

[For20hunter]

We have a 2017 F450 and we have descended some pretty hellacious hills and although occasionally the Ford does apply some brakes to keep it slow, it is really minimal with the exhaust brake activated. Its awesome the slowing power our F450 has when defending without using the brakes at all. Our prior rig was an 2012 F350 DRW with the 6.7 and we had to use our brakes SUBSTANTIALLY more to descend the same hills with lighter trailers.

Rod

 

[travlingman]

I think it is pretty funny that the op of that thread that was complaining about his brakes being used is 12,000 pounds over the weight rating for his truck with the trailer he was pulling. I would be pretty happy if I was that much overweight and my truck had held the speed no matter what it used to do it.

 

[SNOKING]

We have a 2017 F450 and we have descended some pretty hellacious hills and although occasionally the Ford does apply some brakes to keep it slow, it is really minimal with the exhaust brake activated. Its awesome the slowing power our F450 has when defending without using the brakes at all. Our prior rig was an 2012 F350 DRW with the 6.7 and we had to use our brakes SUBSTANTIALLY more to descend the same hills with lighter trailers.

Rod

If you are on cruise control, it maybe that the truck is applying the service brakes without you being aware if it? Chris

 

[For20hunter]

If you are on cruise control, it maybe that the truck is applying the service brakes without you being aware if it? Chris

Chris,

No, the brake lights come on when the system activates the brakes, so I can see them in my trailer when it happens. The rig changes the gears to the appropriate gear and the exhaust brake activates when you let off the accelerator, which together takes care of 90% or better of the slowing. Jerrod Jess (Jesstalkin) and I came down 97 to Biggs Junction (by Maryhill State Park) yesterday and it is a 14% grade and neither one of us had to use our brakes and we both haul trailers weighing in close to 18k.

Rod

 

[SNOKING]

Chris,

No, the brake lights come on when the system activates the brakes, so I can see them in my trailer when it happens. The rig changes the gears to the appropriate gear and the exhaust brake activates when you let off the accelerator, which together takes care of 90% or better of the slowing. Jerrod Jess (Jesstalkin) and I came down 97 to Biggs Junction (by Maryhill State Park) yesterday and it is a 14% grade and neither one of us had to use our brakes and we both haul trailers weighing in close to 18k.

Rod

At 14% you most likely did not have cruise control engaged. Chris

 

[SNOKING]

Some more info from the RV.net forum.

"4x4ord wrote:

It still applies the wheel brakes when set to normal cruise. I did a little more reading in my owner's manual. It explains the following:

Hilly Condition and Trailer Tow
Usage
Note: An audible alarm sounds and the
system shuts down if it applies brakes for
an extended period of time. This allows the
brakes to cool. The system functions
normally again when the brakes have
cooled.
Note: When towing with adaptive cruise
control, turn on Tow/Haul Mode and Diesel
Engine Brake.
Select a lower gear when the system is
active in situations such as prolonged
downhill driving on steep grades, for
example in mountainous areas. The
system needs additional engine braking in
these situations to reduce the load on the
vehicle’s regular brake system to prevent
it from overheating."


Reply by brulaz



Guess I was wrong. Ford seems completely aware of how their AC works under "Hilly Condition and Trailer Tow Usage". They even built in a fail-safe to shut it down when necessary after extended braking.

It would be nice if this shutdown could be manually activated, leaving the old-school CC with just downshifts and exhaust brake control.

 

[For20hunter]

At 14% you most likely did not have cruise control engaged. Chris

No, it was definitely engaged.

Rod

- - - Updated - - -

Some more info from the RV.net forum.

"4x4ord wrote:

It still applies the wheel brakes when set to normal cruise. I did a little more reading in my owner's manual. It explains the following:

Hilly Condition and Trailer Tow
Usage
Note: An audible alarm sounds and the
system shuts down if it applies brakes for
an extended period of time. This allows the
brakes to cool. The system functions
normally again when the brakes have
cooled.
Note: When towing with adaptive cruise
control, turn on Tow/Haul Mode and Diesel
Engine Brake.
Select a lower gear when the system is
active in situations such as prolonged
downhill driving on steep grades, for
example in mountainous areas. The
system needs additional engine braking in
these situations to reduce the load on the
vehicle’s regular brake system to prevent
it from overheating."


Reply by brulaz



Guess I was wrong. Ford seems completely aware of how their AC works under "Hilly Condition and Trailer Tow Usage". They even built in a fail-safe to shut it down when necessary after extended braking.

It would be nice if this shutdown could be manually activated, leaving the old-school CC with just downshifts and exhaust brake control.

There is a fail safe. You just hit your brake or the button on your steering wheel that turns the cruise control off. Then its all about doing it the old fashioned way with no cruise, or in your menu you turn off the adaptive cruise control and its normal cruise control function.

Rod

 

[LBR]

There is a tread going on the RV.net tow vehicle forum about this regarding new Fords with adaptive cruise control. Seems that even when cruise control is in normal mode and not adaptive the truck is using it's service brakes in conjunction with the exhaust brake when descending a grade. This could lead to over heated service and trailer brakes.

https://forums.goodsamclub.com/index.cfm/fuseaction/thread/tid/29640916/srt/pa/pging/1/page/1.cfm

Having not read that site's thread, did anyone mention which mode (Automatic or Manual) they had the exhaust brake in when they noticed the brakes were being applied in adaptive cruise control?

The difference between the 2 modes on how the speed of decent is moderated is definitely different from my experimenting with both modes....wonder if in Manual will not apply brakes and Automatic will?

 

[Jesstruckn/Jesstalkn]

Bottom line is these trucks are amazing, and the cruise works perfectly. the only time the brakes are applied in cruise mode is when you come up on a slower vehicle in front of you and it has to slow down more then the trans and exhaust brake are holding you back. Other then that you will rarely ever see/feel the brake being applied.
For me I run the cruise most of the time with a combination of my foot on the throttle when coming up on trucks and vehicles in front of me to maintain my speed while I change lanes to pass. then going down steep grades I click the manual shift button down to 4th gear (NOT in manual mode) It just set the highest gear the trans is allowed to shift too.
With all of the control options I have at may fingertips THIS NEW FORD TRUCK IS UNBELIEVABLE !!!!!!!

Also Rod and I ran from Kenniwick WA. to Silverton OR. 5 hour drive. He has the 2017 F450 with 4:30 gears I have the 2017 F350 with the 3:55 gears he was leading and we bucking a heck of a head wind for a long way west on 84. We both reset the trip meters in WA. and had the same mileage when we arrived in OR.
250 miles and we were ROLLING we are both pushing 30,000 pound gross weight.
F450 4:30s = 8.4mpg
F350 3:55s = 8.5mpg

 

[ksucats]

The 'exhaust brake' button has two different click modes with tow-haul on. The way I read the manual, and some on-line posts from the Ford Forums, the first is simply the exhaust brake - it will hold the speed as best possible (automatically down shifting if unable to hold in its initial gear) but no service brakes. If you push the button two times in rapid succession you initiate the exhaust brake with service brakes. In this case it will use the service brakes to slow you down if the exhaust brake can not maintain the speed by itself. It is referred to as Auto mode in one of the forums and has a small "A" included with the dash Icon. Took me a while to figure out what was going on - kept seeing my brake lights coming on at night when going down a particular hill near home (no load, simply returning from Fort Riley); the next time no brake lights and not nearly as much speed holding. I believe hitting the button a third time results in turning it off (back to its initial state - identical to its 'off' condition when you first start the truck.) Hope this all makes sense and helps.

 

[LBR]

The 'exhaust brake' button has two different click modes with tow-haul on. The way I read the manual, and some on-line posts from the Ford Forums, the first is simply the exhaust brake - it will hold the speed as best possible (automatically down shifting if unable to hold in its initial gear) but no service brakes. If you push the button two times in rapid succession you initiate the exhaust brake with service brakes. In this case it will use the service brakes to slow you down if the exhaust brake can not maintain the speed by itself. It is referred to as Auto mode in one of the forums and has a small "A" included with the dash Icon. Took me a while to figure out what was going on - kept seeing my brake lights coming on at night when going down a particular hill near home (no load, simply returning from Fort Riley); the next time no brake lights and not nearly as much speed holding. I believe hitting the button a third time results in turning it off (back to its initial state - identical to its 'off' condition when you first start the truck.) Hope this all makes sense and helps.

Correct..press exhaust brake button once for Manual, again for Automatic, again for off....sequence complete.

 

[SNOKING]

Correct..press exhaust brake button once for Manual, again for Automatic, again for off....sequence complete.

Just a FYI.

That is not how the newer RAMs work. First push is full exhaust brake. It comes on when you let up on the throttle. Second push is auto mode and works as described here:

Speed for Auto mode can be set with cruise control or a touch of the brake pedal at a given speed.

Automatic Smart Exhaust Brake Automatic Exhaust Brake technology delivers smoother, less aggressive exhaust braking characteristics during downhill descents. Although it can apply full exhaust braking force if needed, Automatic Exhaust Brake may not apply obvious braking if the vehicle speed is not increasing. Automatic Exhaust Brake is intended to maintain vehicle speed, while Full Exhaust Brake is intended to reduce vehicle speed. Automatic Exhaust Brake can be enabled by pushing the exhaust brake button again any time after the normal Full Exhaust Brake has been turned on. The “Exhaust Brake
Indicator” in the EVIC/DID will change from Yellow to Green when Automatic Exhaust Brake is enabled. Pushing the exhaust brake button again will toggle the exhaust brake mode to off.

It never uses the service brakes and I would not want it to.

It would finish the circle to know how the GM exhaust brake modes work.

Chris