Hill Start Assist Not Available: Causes & Fixes

Is the hill start assist warning light or “Hill Start Assist Not Available” message appearing on your car dashboard?

Don’t panic!

In this post, I will explain everything you need to know about the hill start assist system. Also, you will get a guide on what to do if the system has a problem.

Let’s dive into it!

What Is Hill Start Assist?

Hill start assist is a safety feature that prevents your car from rolling backward when starting on a hill. 

When you stop on an incline, your car will typically roll back a bit when you release the brake pedal to engage the accelerator. This can be dangerous, especially if there are other cars or pedestrians behind your car. 

But with Hill Start Assist, you won’t have to worry about that. The system automatically holds the brakes in place for a few seconds after you release the brake pedal, giving you enough time to get moving without rolling back. Once you accelerate forward, the system will release the brakes and the car will move smoothly up the hill.

You can find this feature on some car brands:

• Ford Focus, Fusion, Escape, and Explorer;
• Subaru Impreza, Legacy, Outback, and Forester;
• Toyota Camry, Corolla, RAV4, and Highlander;
• Honda Accord, Civic, CR-V, and Pilot;
• Volkswagen, Audi, etc.

What Does the Hill Start Assist Not Available Warning Mean?

When the hill start assist warning light comes on, it indicates there is a malfunction in the hill start assist system.

In some car brands like Ford, you also get a “Hill Start Assist Not Available” message.

As the system is temporarily unavailable, you should press the brake pedal to secure your car from rolling away unintentionally. Also, try to find out the cause and fix it as soon as possible.

Why Is the Hill Start Assist Not Available?

Here are two potential reasons why the hill start assist warning light may be on:

Faulty or Dirty Sensors

The hill start assist system uses various sensors to detect the incline of the hill and the pressure on the brake pedal. They include an inclinometer, vehicle speed sensor, wheel speed sensor, brake pressure sensor, etc.

Over time, these sensors can become faulty or covered in debris, which can affect their accuracy. Thus, the system may not be able to detect when the car is on a hill, and the warning light or message may appear.

These sensors are also used in the traction control (TC), electronic stability control (ESC), brake, and anti-lock brake system (ABS). In some cases, if one sensor is malfunctioning, you notice the multiple warning lights come on.

Low Battery Voltage

The hill start assist system relies on the car battery to function properly. If the battery voltage is too low, the system may be unable to operate and trigger the warning light or the “hill start assist unavailable” message to inform you.

What to Do If the Hill Start Assist Is Not Available

Step 1: Check the battery voltage

If the battery voltage is low, recharge or replace it if necessary.

Step 2: Inspect the sensors

Check the sensors for any signs of physical damage or wear and tear, such as cracks or corrosion.

Also, ensure the sensor’s electrical connections are secure and free of dirt and debris. Clean the connections if necessary.

Step 3: Use an OBD2 scanner to identify the problem

In some cases, performing a visual inspection cannot find the malfunctioning components. With a scan tool, you can access your vehicle’s onboard diagnostic system to check for any fault codes related to the Hill Start Assist system. The scan tool will provide you with a code and description of the issue, which can help you determine the cause of the problem.

So, how to use the tool?

• Turn off the engine.
• Connect the scanner to the OBD2 port. Most scanners will have a cable that plugs into the port, while others may be wireless.
• Turn on the ignition.
• Follow the scanner instructions.
• Select the “Read Codes” function on the scanner.

After that, figure out what the codes mean by using the DTC Lookup Library on the scanner or going to the OBD2 Codes Lookup to find meaning, causes, symptoms, and how to fix it.

Step 4: Repair malfunctioning parts

You can replace or repair the malfunctioning part with enough car knowledge and tools. Otherwise, get your car to a professional for inspection and repair.

Step 5: Reset the system

After replacing the malfunctioning sensor in the Hill Start Assist system, you may need to reset the system.

• Use a scan tool to clear any stored fault codes related to the Hill Start Assist system. You can navigate to the clear code’s function in the menu.
• Once the codes have been cleared, turn off the ignition and wait for a few seconds.
• Turn the ignition back on and check to see if the Hill Start Assist system is functioning properly. Take the vehicle for a test drive on a slope to ensure the system engages as expected.

In some cases, the “hill start assist unavailable” message may appear due to a software glitch. Resetting the system by disconnecting the car’s battery for a few minutes may fix the issue.

How to Turn the Hill Start Assist On/Off

In general, hill start assist is a feature that is automatically enabled when the car is started, and it will remain active until the car is turned off. However, in some driving conditions, you may prefer to have more control over your vehicle and choose to turn off the Hill Start Assist system. 

Here’s an example of how you can turn this feature on or off on some Ford models:

• Access the menu on the vehicle information display.
• Select Setting → Drive Assist.
• Locate the Hill Start Assist option to turn it on/off.

Please note that this process may vary for different car models. It’s always best to consult your car’s owner’s manual for specific instructions on how to operate the Hill Start Assist system in your vehicle.

Final Thoughts

Understanding how the hill start assist works is essential for you to avoid stalling or rolling back on an incline. By following the steps outlined above and practicing, you can gain confidence in using this system. 

If you encounter different situations while using hill start assist, feel free to share them with me in the comment box below. 

Remember to always stay safe while driving!