2014 GMC Sierra Hill Descent Control

JC59 · June 17, 2019

Does anyone know how to disable the Hill Descent Control on the 2014 GMC Sierra?

Here is the problem: When traveling down a hill at around 40 to 45 mph I will have to brake along the way to the bottom of the hill. All of a sudden the transmission will kick down to a lower gear and my rpm's on the engine will almost RED line. I usually have to shift into neutral to get this to stop. I have tried using the transmission in the manual mode making sure I manually shift into 6th gear before taking off. This seems to work fine but if you forget to do this before you begin driving you will need to come to a complete stop and do your manual shift. Otherwise if you do it on the fly the manual gear setting might be in 1st gear and that is not good.

I also found that I can press the button in the end of the transmission shifter and hold it for at least 5 seconds and this will disable it. The only problem with that is you have to remember to do it every time you re-start the vehicle because the default is always on.

I would like to permanently disable this feature. It is one of the most annoying features on this vehicle.

JimCost2014 · June 17, 2019

1 hour ago, JC59 said:

Does anyone know how to disable the Hill Descent Control on the 2014 GMC Sierra?

Here is the problem: When traveling down a hill at around 40 to 45 mph I will have to brake along the way to the bottom of the hill. All of a sudden the transmission will kick down to a lower gear and my rpm's on the engine will almost RED line. I usually have to shift into neutral to get this to stop. I have tried using the transmission in the manual mode making sure I manually shift into 6th gear before taking off. This seems to work fine but if you forget to do this before you begin driving you will need to come to a complete stop and do your manual shift. Otherwise if you do it on the fly the manual gear setting might be in 1st gear and that is not good.

I also found that I can press the button in the end of the transmission shifter and hold it for at least 5 seconds and this will disable it. The only problem with that is you have to remember to do it every time you re-start the vehicle because the default is always on.

I would like to permanently disable this feature. It is one of the most annoying features on this vehicle.

Believe you answered your own question.

Welcome to the site, and before you are attacked by the masses, you are talking about the "grade braking" system.

HDC is an option with the Z71/Denali package for controlling your "very slow" downhill decent, kind of like a "crawl mode".

RACERX7775 · June 17, 2019

I think you are in tow/ haul mode. Turn tow/haul off and its fine. Done.

Ozer · June 17, 2019

Pressing the button each time is the only way to turn off. Im sure its doable with a tune but if you arent going that route, no other way.

tyler.frost92 · June 18, 2019

Youre talking about grade braking, not hill descent control.

dangav · June 28, 2019

Press and hold the tow mode button for 5-10 seconds to turn it on and off. Works in my 14 slt

tyler.frost92 · June 28, 2019

Anytime grade braking has kicked in for me it only drops enough gears necessary to control my speed that it recognized i was braking to maintain. Never redlined and usually happens on downhill off ramps from the freeway or when I'm hauling something. I dont believe theres a way to disable it, except for holding the tow haul button for 5 seconds every time you start the truck.

2kwik4u · June 28, 2019

On 6/16/2019 at 8:23 PM, JC59 said:

Does anyone know how to disable the Hill Descent Control on the 2014 GMC Sierra?

Here is the problem: When traveling down a hill at around 40 to 45 mph I will have to brake along the way to the bottom of the hill. All of a sudden the transmission will kick down to a lower gear and my rpm's on the engine will almost RED line. I usually have to shift into neutral to get this to stop. I have tried using the transmission in the manual mode making sure I manually shift into 6th gear before taking off. This seems to work fine but if you forget to do this before you begin driving you will need to come to a complete stop and do your manual shift. Otherwise if you do it on the fly the manual gear setting might be in 1st gear and that is not good.

I also found that I can press the button in the end of the transmission shifter and hold it for at least 5 seconds and this will disable it. The only problem with that is you have to remember to do it every time you re-start the vehicle because the default is always on.

I would like to permanently disable this feature. It is one of the most annoying features on this vehicle.

Why do you want to disable it? Is it just annoying? Do you think you'll damage the engine? Something new and different that you've never needed in the past so by god you don't need it now?

The engine will take the revs just fine. It's providing safety margin over your existing brake setup under a heavy load. I use it often (long down grade towing our boat), and find it works well, so I'm curious whats annoying about it?

Ozer · June 28, 2019

Trying to maximize mpg? If im not towing anything and going down hill i will turn it off, idk if it helps with mpg? maybe not?

aseibel · June 28, 2019

I rarely notice grade braking on mine, but once in a while when it kicks on, I press the button and turn it off.

I believe you must be coasting with zero throttle and going downhill for it to engage.

RACERX7775 · June 28, 2019

I think its zero throttle, brakes applied, but picking up speed. It helps so you dont get brake fade or loose brakes completely. Thats why they have run away truck ramps in mountain areas. If you stay on the brakes to long, they will overheat and become useless... Then lookout........

2kwik4u · June 28, 2019

1 hour ago, Ozer said:

Trying to maximize mpg? If im not towing anything and going down hill i will turn it off, idk if it helps with mpg? maybe not?

Theoretically it does help with MPG.

When at zero throttle and maintaining speed the ECM turns off the injectors, so you get a theoretical infinite miles per gallon. The more time you spend travelling without using fuel the better average mpg you get. used to be called Decel Fuel Cutoff (DFCO), not sure if it still works under the same name in the newer ECM's.........However it does this regardless of grade braking active or not.