Chevy Cruze Service Brake Assist (6 Causes and Solutions)

As technology advanced, so did the braking system in vehicles, which made braking much safer and less taxing on the driver.

Today’s topic of discussion is the popping up of the ‘Service Brake Assist’ error on the dashboard of the Chevy Cruze. 

The ‘Service Brake Assist’ error message is usually down to a faulty brake booster, vacuum pump, or a broken master brake cylinder; furthermore, a faulty master cylinder leads to dirty and useless brake fluid. All these causes lead to brake pedals that are very hard to press and unresponsive brakes.

I shall look at all possible causes of this error message and the possible solutions. Without further ado, let’s dive in!

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What is Brake Assist?

Brake Assist is a part of the braking system. It is a feature that was first introduced by Mercedes-Benz in 1996.

Brake assist works by adding additional braking force to your car when you have to come to a sudden stop. 

Drivers’ reaction times don’t always match how quickly they need to react to avoid a crash.

If Brake Assist notices drivers slamming the brake pedal, it applies maximum force to the brakes to help make sure the car stops as quickly as possible. 

Brake Assist vs. ABS

People often get confused and think of Brake Assist and ABS as the same thing. 

Brake Assist increases the braking force applied when coming to a sudden stop, while ABS, which stands for Anti-Lock Braking System, is an anti-skid feature that increases the tires’ traction when coming to a sudden stop.

What Does the ‘Service Brake Assist’ Error Message Mean on A Chevy Cruze?

The ‘Service Brake Assist’ error message is a message that pops up on the dashboard of the Chevy Cruze. It usually means a problem with the brake assist, possibly due to many reasons. 

Since there is a slight chance that this error message could be due to a software glitch, there is a way to make sure for certain if the Brake Assist feature is working or not:

1. Turn off the engine and press the brake pedal; it should go all the way down slowly but surely.

2. Now pump the brakes, which should gradually become hard to press, indicating that the brake assist is working.

Make sure to do this with the accessory position, as the brake gets locked when the key is turned off. 

6 Major Causes for The ‘Service Brake Assist’ Message Appearing on A Cruze

Brake Booster

Brake Booster is the bridge between the brake pedal and the master cylinder. Its function is to add additional force to the already existing force of the brake pedal even further. 

It is done by having the brake booster utilize the power of the engine’s vacuum to emphasize the force your foot uses on the master cylinder. 

A faulty Brake Booster could be one of the reasons why the ‘Service Brake Assist’ error message pops up on the Chevy Cruze. Some signs that might indicate a faulty Brake Booster are:

  • The brake pedal will become much harder to press
  • The car will not brake as efficiently and will require a longer distance to come to a stop
  • Unfortunately, if the seals inside the Brake Booster are broken, it can cause the car’s engine to stall; furthermore, it can cause damage to the master cylinder as well

Electric Vacuum Pump

The vacuum pump in the Chevy Cruze receives power through a vacuum line from the engine. 

The vacuum is circulated through the brake booster, which applies pressure to the hydraulic brakes when the brake pedal is pressed. 

The Vacuum pump in the Chevy Cruze has a Solenoid that has been known to stop working occasionally.

It is recommended to have it checked at your nearby auto shop.

Low Brake Fluid

Brake fluid runs like blood through the brake fluid lines and delivers blood; I mean brake fluid to the slave cylinder (brake pistons), so they can exert force and stop you from going too fast too furious.  

The brake fluid can accumulate a lot of contaminants, and have itself rendered useless, so here is how to maintain a proper fluid:

  • Locate the brake fluid reservoir in the Chevy Cruze. When you pop the car’s hood, you should see a white container with a black and yellow cap.
  • On the outside of the reservoir, you should see “minimum” and “maximum” lines. Check the brake fluid against these lines. If the brake fluid is closer to the minimum line, it’s time for a brake fluid replacement
  • Check the color of the brake fluid. If it is black and resembles oil, you’ll have to get the brake fluid flushed and replaced.

Here’s the brake fluid you need in case the level is low. 


Prestone AS401 DOT 3 Synthetic Brake Fluid – 32 oz.

Improve your safety in high-stakes braking scenarios with Prestone, offering an additional margin of security. Ideal for ABS, disc, and drum brake systems, it ensures reliable performance across various braking conditions.

Check Price

Failing Master Brake Cylinder

The master brake cylinder is responsible for providing hydraulic pressure through the brake fluid and controls it mechanically.

The master cylinder is responsible for creating the pressure that is provided to the brake assist system. 

So you can say that the master brake cylinder is a very important component. Since it is responsible for creating pressure, a telltale sign of a broken master cylinder is that the brake pedal will feel very soft and light.

Another sign to look out for is polluted brake fluid and brake fluid leakage. The master cylinder has rubber seals that help create a vacuum, and it can wear down, causing the fluid to get contaminated. 

Another aftermath of this worn-out rubber seal is the pressure loss; the system won’t be able to maintain pressure, and your brakes will go to heaven. 

Disconnected/Incorrect Vacuum Hose

The vacuum line in the Chevy Cruze uses a very specific vacuum hose that, as the name suggests, helps create a vacuum. 

If any other kind of hose is used as a replacement for it, that hose might not hold the vacuum and will collapse, leaving a non-functioning vacuum line.

A simple cause, yet there you have it.

Malfunctioning Brake Sensor

Lastly, the ‘Service Brake Assist’ message on the Chevy Cruze could be down to a malfunctioning brake sensor.

It can also be indicated by the ABS light being illuminated. It is a relatively simple fix that can be done by just having the brake sensor replaced.


Since most of the causes for the ‘Service Brake Assist’ message are very technical, it is not recommended to DIY any solutions. 

The best course of action would be to take your Chevy Cruze to your nearby dealership, where hopefully, any issues will be covered in your Bumper-2-Bumper warranty. 

What you can do is to keep a check on the brake fluid, as it can be an indicator of several issues, as mentioned above.

Wrap Up

Well, there you have it. Hopefully, I provided a thorough and detailed article regarding the numerous reasons why the annoying ‘Service Brake Assist’ message appears in the Chevy Cruze. 

Since this error message alerts you about a fairly technical issue that mostly cannot be handled by yourself at home, no real solutions can be provided.

It is something only a qualified professional will be able to fix.

The braking system is the most important feature of a vehicle, so it is of utmost importance for all passengers’ safety that any problem related to any part of the brakes be fixed as quickly as possible. 

I hope the solutions I have provided will help you solve all these annoying problems.


How Does a Brake Booster Go Bad? (Signs of Failure)

Faulty Brake Issue Forces Recall of 300,000 Chevrolet Cruze Cars

What are the Symptoms of a Failing Brake Master Cylinder? – Gordon Automotive