Service Brake Assistance - Definitions, Causes & Fixes

Today’s modern vehicles have many advanced driver-assist functions installed for better control. The brake assist function is an example of one such system. If something goes wrong, you may see a “Service Brake Assist” alert on the dashboard. What does “Service Brake Assist Mean,” and how should you fix it?

In this guide, we talk about the meaning of the “Service Brake Assist” warning. The Brake Assist system is compared to ABS and Automatic Emergency Braking. We will also discuss the many benefits this safety system offers. Some of the most frequently asked questions are answered. You should read our article on how to fix the warning lights before you rush. 

What does the Service Brake Assist message mean?

If the Service Brake Assist message is displayed on your dashboard it indicates that the Brake Assist has failed. It’s possible that a brake sensor has failed or there isn’t enough pressure in the brake system. You should inspect it immediately.

Brake assist measures the pressure on the brake pedal. This advanced system provides additional power if more pressure is required in an emergency. 

Benefits of Brake Assist

Brake Assist monitors how much pressure is being applied to the brake pedal. This system ensures sufficient pressure to avoid collisions in an emergency stop. 

If the system determines that a fast stop is necessary, but you haven’t fully pressurized the pedal, extra hydraulic pressure will be applied. This increases the distance that the vehicle will stop completely. You can avoid an accident, and it is priceless. 

ABS or Brake Assist

Brake Assist can be found in many modern cars as a safety feature. It’s not identical to anti-lock brakes (ABS), which are included with every vehicle these days. Both systems improve the braking performance. 

Brake Assist can supply additional pressure on the brake pedal if there’s an emergency. The brake assist helps motorists stop in the event of a collision. ABS, on the other hand maintains the vehicle's braking if it locks up. This gives you more control over the vehicle. ABS keeps your car's wheels from locking up and allows you to safely come to a halt. 

Brake Assist Vs. Automatic Emergent Braking

Brake Assist might sound like a form of Automatic Emergency Braking, but these two aren’t the same. Brake Assist will apply pressure to your feet. The advanced Brake Assist system will give you the boost you need if you don't push too hard on the pedal.

The Automatic Emergency Braking system will work automatically without you having to input any commands. If there’s a dangerous situation determined by the sensors and you aren’t braking despite warnings, the car will brake on its own. It’s an autonomous technology that handles the operation for you. It’s normally included with vehicles as part of a safety package or it can be added as an optional feature. 

Causes for the Service Brake Assistance Message

If you receive a message about service brake assistance with no ABS or other messages, most likely it's caused by either a bad brake pressure sensor, or a malfunctioning brake light switch depending on your car model. However, there are many different reasons why this message appears, so a proper diagnosis is necessary, so let’s take a look.

The Service Brake Assist message can be caused by the following:

You may have bigger brake problems if you receive this message along with Service Stabilitrak messages, Service Traction Control messages, and ABS lights.

Helpful Tips to Repair Service Brake Assist

1. The Light is Back!

There’s always the chance that the light came on by accident. It’s unlikely, but you want to rule this option out before moving on. By resetting the brake assist light, you can ensure that there’s actually a problem. 

OBD2 scanners are the most effective way to achieve this. However, if you don’t have access to one you can also try to remove the power.

With the vehicle in a location that’s safe and the engine off, you can disconnect the negative cable to the battery. You can then remove the battery from the vehicle by pressing the brake pedal. When that's done, connect the cable to your battery. Then start the engine. At this point, the light should turn off.

To check if it turns on again, take the car for a drive. You can continue to the next steps if it turns on.

2. Learn the trouble codes

You can read trouble codes on modern cars with an OBD2 scanner. This makes diagnosing problems much simpler. An OBD2 scanner can be purchased for home or you might need one to fit your vehicle's brake assist system.

Continue troubleshooting once you've read all the codes.

3. Verify the Brake Pressure Sensor

Brake pressure sensors are a key component of brake assistance systems. A failed sensor could cause the entire system to fail. The sensor should be replaced in order to correct the problem. The ABS unit, or the master brake system, are the most common locations for this sensor. It can also be found on certain models of cars.

This part is available for $10-150. If you can get the sensor installed on your own, you won’t have anything else to spend. The cost of installing the sensor may be $75 to $200, even if you hire a technician. 

4. Vacuum leaks should be checked and the valve should be checked.

A vacuum is essential for the brake booster's proper operation. Most vehicles will have a connection from the intake manifold to supply a vacuum. The check valve keeps the vacuum within the booster in place when you accelerate your car.

You may lose your brake pressure if the check valve breaks or there's a leak in the vacuum. The service brake assistance system might also pop up if this happens. A faulty vacuum pump could cause a problem with a diesel engine.

5. Check Brake Fluid

The system’s brake fluid is what helps to create pressure. This hydraulic fluid is needed when you push down the brake pedal and it’s utilized by the brake assist system. Low levels of hydraulic fluid can cause you to not be able to get the pressure needed for you brake pedal to work properly.

Check the level of your brake fluid. With the transparent indicators located on the reservoir or dipstick cap, it is easy to see if you need more. 

It is a good idea to flush the brake fluid if it looks cloudy or dirty. This service is normally priced at around $100. 

RELATED: 5 Symptoms of a Brake Fluid Leak (& Repair Cost)

6. Repair Brake Boosters

It is the part that increases the brake force applied to the master-cylinder. It’s the component that differentiates a power-assist braking system from a manual setup. 

You can get the Service Brake Assist Warning Light if your brake booster goes out. The brake booster can be replaced by you yourself. This could cost you between $100 and $500. You could also spend $150 to $450 to have the part replaced by a professional. These prices can be inflated based on the year, make and model of your vehicle.

7. Repair damaged ABS components

The ABS system may have a problem if you get the message "Service brake assistance" along with the ABS or traction light. Bad ABS sensors, bad ABS rings and bad ABS pumps are the most frequent problems that could cause brake assistance problems.

You can learn more about it here: ABS Light – Meaning, Causes, Fixes (& Is it safe to drive with?)

8. Talk to a mechanic

If none of these steps led to a repair, it’s time to talk with your mechanic. With the sophisticated technology, such as the Brake Assist system, it can be difficult to pinpoint what’s wrong.

But certified mechanics can access better diagnostic equipment. This means that they may be better equipped than others to find the cause of the problem.

FAQ about Brake Assist