If you have a RAM pickup truck with an Off-Road package, or Power Wagon package you’ll have hill descent control (HDC).

What is hill descent control?

Hill descent control is a downhill assist system that controls the speed of the vehicle without driver input. It’s almost like a very slow cruise control designed to help with off-road driving. Braking and acceleration are needing when the system is in action, taking some of the strain off the driver.

downhill assist

Hill Descent Control button is the one looks like the truck is pointing down a slope.                                                                                             Photo: L Baures

There are 3 modes

  • Off
  • Enabled
  • Active

Off– The system is off

Enabled– System is ready but not active (ie. the driver has overridden the system by pressing brake or accelerator). Solid HDC dash light will appear.

Active– The system is on and the truck is actively controlling the speed downhill. Solid HDC dash light will be on.

Turn on Hill Descent Control

For the system to be enabled, these following conditions must be met.

  1. Push the Hill Descent Control Button to turn on (usually on the lower part of the center console panel). Dash light will appear.
  2. Shift to 4WD LOW RANGE
  3. Parking brake released
  4. Driver door closed
  5. Vehicle speed below 5mph

If the conditions are not met, excessive speed or overheated brakes are detected, the dash light and switch lamp will flash, then turn off.


The system will start automatically when the truck is driven down a grade steep enough.

Change speed

shifter truck

+ and – buttons enable manual gear shifts                                   Photo: L Baures

Using the +/- on the shifter, there are up to 9 different speeds the driver can choose from;

  • R = 0.6 mph (1 km/h)
  • N = 1.2 mph (2 km/h)
  • D = 0.6 mph (1 km/h)
  • 1st = 0.6 mph (1 km/h)
  • 2nd = 1.2 mph (2 km/h)
  • 3rd = 1.8 mph (3 km/h)
  • 4th = 2.5 mph (4 km/h)
  • 5th = 3.1 mph (5 km/h)
  • 6th = 3.7 mph (6 km/h)
  • 7th = 4.3 mph (7 km/h)
  • 8th = 5.0 mph (8 km/h)
  • 9th = 5.6 mph (9 km/h) – If Equipped

At any time, the driver can pause the system by braking or accelerating. The system will also deactivate (but remain engaged) if the grade of the hill becomes insufficent (ie. too flat), or is on an uphill grade. If the truck does more than 20mpg but less than 40mph or shifted to park (P).

Turn Hill Descent Control Off

The system will turn off completely if;

  • The Hill Descent Control button is pressed to switch off.
  • Truck is no longer in 4WD LOW.
  • Driver door opens.
  • The parking brake is ON.
  • The Truck is driving at more than 20mph for over 1 min 10 seconds.
  • Speed goes over 40mph.
  • Excessive brake temperature is detected.


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“Owner’s Manual RAM 2500.” Official Mopar Site , www.mopar.com/ramtrucks/en-us/care/dynamic-manuals/viewer.html?id=1147&topics=GUID-2D1974CB-8CA0-4B43-BEE3-3D75F2805CAE&tocID=2017.