Engine brake question, does this act like a Jake brake?
how do I use it, trying to understand the Manuel states turn it on/off with button at/near the radio, or just push the button that looks like a exhaust within circle. Thanks.

 

Yes the Owners Manuel is confusing at times..... "My Understanding" is that it just holds back the exhaust gas VIA a flapper in the exhaust pipe, rather than the "Jake Brake" type of braking. In "Tow/Haul" mode, the Exhaust brake is activated automatically. Yesterday for the first time I activated the Dash Mounted brake by pushing the button. Guessing it's an option to be used independent of the Tow/Haul mode. I have not got this far in the Owner's Manual yet. Take it with a grain of salt.

 

It's not a Jake brake. It's also not technically an exhaust brake, it utilizes the vanes in the VGT turbo to create backpressure (engine braking). I would think it also adjusts the transmission to downshift sooner, similar to tow/haul. The manual states you can activate by pressing the button once, or press it twice and release the throttle to set the speed you wish to maintain.

 

Correct as you state, mostly. Technically it does not actually use back pressure to retard the engine. The vanes, as you said, are changed to create more boost at lower rpms of the turbo and that raises the compression in the engine without adding fuel.:

Yes I understand the shift points are changed in order to increase the RPM to the top of range in order to compress more air.

 

When towing in the Sierras I first set the CC at 60 mph and then hit the TH button and engine brake button. This keeps the truck within 4 mph wether climbing or descending. Mammoth to Bishop I use the brakes once and that's for a curve where 60 mph doesn't feel comfy.

 

Were you towing??

 

Exhaust brake does *not* activate automatically with Tow/Haul. You have full on, and then Auto mode, and then off.

Tow/Haul will downshift the engine as you apply the foot brake to add engine braking and help slow the vehicle down. However, the exhaust brake must be switched on separately if you want that benefit.

The exhaust brake is massively more helpful in slowing the vehicle down compared to downshifting alone.

Activating full exhaust brake on basically does nothing without Tow/Haul or Cruise Control engaged.

However, Auto mode actually works pretty well. Without even having Tow/Haul or Cruise engaged, simply take your foot off the accelerator at the top of a hill. The truck "remembers" your speed and lets the vehicle speed up maybe 3-4mph...then it will automatically downshift to give the exhaust brake the necessary RPMs to work. The truck will slow down, and if you don't touch the accelerator, it will continue to slow beyond your initial speed.

Auto mode is designed to be more smooth especially as you hit the accelerator again.

In reality, the best way to use the exhaust brake is to shift the truck into "M" mode, activate the Full exhaust brake, and use the +/- buttons on the shifter to drop down a gear or two or three which will provide all the braking you need without touching the brakes.

 

that’s nice the EB can be used in manual mode. on my GMC the exhaust brake only works in Drive. pretty lame.

 

Although moving the shift lever, at least on the '15 I used last, is almost difficult to be careful to only move to manual, especially on bumpy roads. The MKC with the pushbuttons on the dash is very easy to change the operation into sport mode which in turn will allow the transmission to stay in the selected gear with the flappy paddles on the steering wheel, which are also much easier to use than the small slide on the shift lever. Ford take note, the manual mode could be easier to operate!

It is interesting that even though there is no engine braking per say on the MKC the sport mode with cruise control on will automatically utilize lower transmission gears to reduce speed while in cruise control on a downgrade.

 

Is there anything that displays the EB is active when in auto mode? So you know it is being used as opposed to the truck downshifting automatically or both going at the same time?

 

No. You just get the exhaust brake symbol with the "A" when the button is engaged. The boost gauge will fluctuate a tad, but that's about it.

It doesn't have an option like the Cummins where it shows you how much braking HP is being applied.

 

Second word in the first sentence.

 

Although there is no icon or info on the screen stating the EB is actively operating, the turbo boost gauge will show pretty heavy boost (25-60% from my experience) while your foot is completely off the throttle, so you know its working. You can also clearly hear a difference in engine tone.

 

Great info in this thread - thanks guys!!

 

I used it while towing my 16k fifth, works great very smooth but really helps your stopping power, for when that signal changes at the last minute and you have to slow the freight train really quick........Much better than my 2011 f250 that just downshifted