The “Hill Descent Control Fault” or “Hill Descent Control Malfunction” (depending on your Ford model) is one of the most common alerts on Ford vehicles, and it can be really unpleasant to experience.
But don’t worry, I’ve got you covered because, in this article, I am going to explain what this message means, why it happens, and how to fix it. Let’s get into it!
What is Hill Descent Control on a Ford?
Before we dive deeper into what is causing the “hill descent control fault” alert on your Ford,
It’s important first to understand what hill descent control is and how it works.
Basically, the Hill Descent Control System (HDC) is like an advanced cruise control-like system that helps automatically control your vehicle’s speed when going down steep hills.
It uses the anti-lock brakes and traction control technology already built into your vehicle to help maintain a steady preset speed down the hill.
As you’re descending, it constantly adjusts the braking pressure to help prevent wheel slippage and keep the vehicle at the speed you’ve set.
This takes a lot of the effort out of going down steep grades, as you don’t have to ride the brakes or downshift the transmission nearly as much.
This Hill Descent Control system can maintain speeds between 2-12 mph on the downhill.
If you happen to be going over 20 mph, it remains active in the background but won’t re-engage to set a descent speed until you drop back below 20 mph again.
So, in essence, this system acts like an advanced cruise control just for going down steep hills. It uses anti-lock brakes to maintain a steady preset speed for you, letting you focus more on steering and less on braking.
Going downhill is made easier and more controlled.
What Does Ford’s “Hill Descent Control Fault” Alert Mean?
Now that I have briefly explained what Ford’s HDC System does, let’s get into what the alert means.
In simple terms, when the “Hill Descent Control Fault” or “Hill Descent Control Malfunction” message pops up on your dashboard, It means the computer (PCM) has detected some kind of problem with the HDC system.
It can be caused by a simple thing such as a bad wheel sensor or a more serious problem such as a faulty ABS control module.
As an auto technician, I will now provide a list of the primary causes based on my experience below.
Hill Descent Control Fault Causes
Now let’s look at the leading causes for this warning alert:
1. Faulty Brake Switch:
The most common cause of Hill Descent Malfunction is a Faulty Brake light switch.
The brake switch detects when the brake pedal is pressed.
If it malfunctions, it can’t properly signal the Hill Descent Control module that brakes are applied, preventing the system from activating.
2. Bad Wheel Speed Sensor:
The second most common cause of this alert is a bad wheel speed sensor (also known as an ABS sensor).
These sensors monitor the speed of each wheel. If one fails, the Hill Descent Control system won’t have accurate wheel speed info to function properly.
The sensor will need to be replaced to restore operation.
3. Low Battery Voltage:
Just like most electronics on your Ford, the Hill Descent Control relies heavily on proper battery voltage.
If the battery voltage goes below a certain point due to a bad battery/ low charge, it may cause the system to malfunction.
4. False Alarm from Battery:
Sometimes when reconnecting or replacing the battery,
it can cause odd errors in the computer system, including false flags for the Hill Descent Control.
Often the faults clear up on their own after a battery reset.
5. Faulty/Damaged Steering Rack:
The steering rack is responsible for communicating the vehicles direction and movement to the computer system.
If it is damaged or faulty, it can cause issues with the Hill Descent Control. Although this is a less common cause of the “hill descent control fault”
There are more than enough cases from Ford owners where the steering rack has been the cause of this error.
6. Bad ABS Module:
The ABS (Anti-lock Braking System) module is a key component that the HDC relies on. It houses the logic and valves that modulate brake pressure during ABS braking events.
If the ABS module is malfunctioning or damaged, it can cause a disruption in communication and signals with the Hill Descent Control system and trigger a fault code.
7. Blown Battery Fuse:
The final common cause of the “hill descent control fault./malfunction” is a blown fuse.
In addition to the specific Hill Descent Control fuse, there may be other fuses connected to components like the ABS module, brake control module, etc. that the system relies on.
If any of these related fuses blow, it can interrupt the communication network and cause a hill descent control fault.
Checking and replacing any blown fuses related to the brake or traction control systems may help resolve a fault code.
How to Fix and Reset the Hill Descent Control Fault Message on a Ford
Lastly, lets look at how to go about solving this problem.
Disconnect and Reconnect the Battery
The first thing that I recommend that you do when this alert shows up on the dashboard is disconnect and reconnect the battery.
This is a good way to reset the computer, and it can sometimes clear up problems like this one.
Check the Battery Voltage
If the alert doesn’t go away, the next thing to test is the battery voltage itself,
You can take your Ford to the nearest AutoZone and they will be able to test it for you for free.
if the battery is bad replace it with a new one.
Get a Diagnostics
If the you disconnected and reconnected the battery and the condition of the battery is still good.
As a mechanic, I would advise you to have your car scanned with an OBD diagnostic tool.
The scanner will read all the stored codes and tell you what’s wrong with your car.
You can take it to any nearest Ford Dealership or or an independent mechanic.
If you want to try to fix the Hill descent control malfunction yourself, without scanning the vehicle, below are the best places to start.
Change the Brake Switch
If the “Hill Descent Control Fault” warning is still showing on your Ford, then the next thing that you should check is the brake switch itself.
It is relatively simple to change and can often be done by yourself,
however if you not mechaniccally inclined it is best if you take your Ford in for a professional mechanic to do this for you.
Change Wheel Speed Sensors:
If the “Hill Descent Control Fault” warning is still showing on your Ford, then the next thing that you should check is the wheel speed sensors.
These are located on each axle of your vehicle. I would advise you to replacing all four at the same time.
This should fix the issue.
Take Your Car to a Qualified Repair Garage/Dealer:
If doing the above things doesn’t fix the “Hill Descent Control Fault” then the next thing that you should do is take your car to a qualified repair garage or Ford Dealer.
They will be able to diagnose the problem and fix it for you.