What happens when the ABS system fails?

When the anti-lock braking system (ABS) in a vehicle fails, it can have serious consequences for the driver's ability to control the car and avoid accidents. The ABS system is a crucial safety feature that helps prevent the wheels from locking up during sudden braking, allowing the driver to maintain steering control and stop the vehicle more effectively.

How the ABS System Works

The ABS system uses sensors to monitor the speed of each wheel. When the system detects that a wheel is about to lock up, it automatically pulses the brake on that wheel, preventing it from locking and allowing the driver to maintain control of the vehicle. This helps the driver avoid skidding and losing control, especially on slippery surfaces like wet or icy roads.

Symptoms of ABS Failure

There are several common signs that the ABS system has failed, including:

• The ABS warning light illuminating on the dashboard


• The brakes feeling "spongy" or less responsive than normal


• The wheels locking up during sudden braking, causing the vehicle to skid


• The vehicle pulling to one side during braking

If the ABS system fails, the driver will need to be extra cautious when braking, as the wheels may lock up more easily, leading to a loss of control and increased stopping distances.

Causes of ABS Failure

There are several potential causes of ABS failure, including:

• Faulty wheel speed sensors


• Electrical issues in the ABS control module


• Worn or damaged brake components


• Contamination in the brake fluid

If the ABS system fails, it's important to have the vehicle inspected and repaired by a qualified mechanic as soon as possible to ensure safe driving.

Driving with a Failed ABS System

When the ABS system fails, the driver should take the following precautions:

• Avoid sudden, hard braking, as this can cause the wheels to lock up


• Increase following distance from other vehicles to allow for longer stopping distances


• Drive at slower speeds, especially on slippery surfaces


• Be extra cautious when turning or changing lanes, as the vehicle may be more difficult to control

While it's possible to drive with a failed ABS system, it's not recommended, as the increased risk of losing control and being involved in an accident is significant. The safest option is to have the vehicle repaired as soon as possible.

Can you drive with failed ABS?

The ABS light is yellow for a reason – it indicates that caution should be taken while driving the vehicle, but there is no imminent need to stop. It is wise to get the system checked out sooner than later, but waiting until your next paycheck isn't a bad timeframe.

What to do if the ABS system fails?

If your anti-lock braking system (ABS) is not working, you should drive cautiously, avoid sudden stops, and have the system serviced as soon as possible. While the standard brakes should still function, the ABS warning light indicates a problem that can make emergency braking more dangerous, increasing the risk of wheel lock-up and skidding. 
This video explains what to do when your ABS warning light comes on: 49sMechanic BaseYouTube · Mar 15, 2024
While driving

• Drive cautiously: Maintain a safe following distance and avoid aggressive driving. 
• Avoid hard braking: The ABS is designed to prevent wheels from locking up, so its failure means a greater risk of skidding if you slam on the brakes. 
• Apply steady, firm pressure: If you need to brake hard, press the pedal down firmly and hold it. Do not pump the brake pedal, as this is counterproductive in a car with a functioning ABS and could be dangerous if the system is failing. 

Next steps

• Get it serviced: Drive to a qualified mechanic or a repair shop to have the system inspected and repaired. 
• Check your owner's manual: It may offer some basic troubleshooting steps, such as checking for blown fuses or low brake fluid, which can sometimes trigger the ABS light. 
• Don't ignore the light: If the ABS warning light is on, there is an issue, and it's crucial to have it diagnosed by a professional. 

You can watch this video to learn how to diagnose the problem yourself: 48s8020 AutomotiveYouTube · Jul 21, 2024

What are the symptoms of a faulty ABS?

Common symptoms of an ABS failure include the ABS warning light illuminating on the dashboard, brake pedal issues like sponginess or locking up, and the brakes locking up or skidding during hard braking. You may also notice other brake problems, unusual noises, or a speedometer malfunction, as wheel speed sensors are also used for the speedometer. 
Dashboard warning light 

• The ABS warning light will turn on, similar to a "check engine" light. This is a clear indicator that the system has detected a problem. 

Brake pedal issues 

• Spongy or unresponsive: You may have to press the pedal multiple times to get a response, or it may feel soft or spongy. 
• Locks up: The pedal may become stiff and lock up, preventing you from applying the brakes effectively. 

Braking performance 

• Brakes lock up: The brakes may lock up when you slam on the brakes, causing the car to skid or lose control. 
• Longer stopping distances: The car takes longer than usual to stop. 
• Increased effort: You may need to apply more force to the brake pedal than you normally would to achieve the same stopping power. 

Other potential symptoms

• Unusual noises: You might hear clicking or other unusual sounds from the brakes. 
• Speedometer problems: The failure of a wheel speed sensor can cause inaccurate or erratic speedometer readings. 
• Pulling to one side: The vehicle may pull to one side during braking. 
• Hesitation during acceleration: In some cases, there may be hesitation when accelerating. 

Is it expensive to fix an ABS problem?

Yes, fixing the Anti-lock Braking System (ABS) can be expensive, with the total cost depending on the specific component that needs repair, the vehicle's make and model, and the extent of the damage. While simple fixes like a broken wire or sensor can be relatively inexpensive, replacing major components like the ABS control module can range from hundreds to over a thousand dollars, and sometimes even more for complex systems. 
Factors that influence cost

• Component: The cost varies significantly depending on whether the issue is with an ABS wheel sensor, the hydraulic pump, or the main control module. The control module is typically the most expensive part. 
• Vehicle make and model: Luxury, high-performance, and hybrid vehicles can have more complex systems that are more costly to repair. 
• Severity of damage: Minor issues like a broken wire or a faulty sensor will be cheaper to fix than problems with the ABS control module or physical damage to the system. 
• Labor costs: The cost of labor, which varies by location and the time required for diagnosis, can add a significant amount to the total repair bill. 
• New vs. used/remanufactured parts: Using a used or remanufactured part can lower the cost, but the quality and availability of these parts can vary. 

Example costs

• Wheel sensor replacement: Can cost between $100$ 100$100 and $200$ 200$200 for the part. 
• ABS control module replacement: Can range from $600$ 600$600 to over $1,200$ 1 comma 200$1,200 for many domestic vehicles, but can be as high as $2,000$ 2 comma 000$2,000 or more depending on the car and if a new, dealer-supplied part is used. 
• Total repair cost: A typical repair that involves replacing several sensors can cost over $1,000$ 1 comma 000$1,000. 

What you can do

• Get a diagnostic scan: Have a mechanic perform a diagnostic scan to pinpoint the exact problem and get a more accurate estimate. 
• Shop around: Get quotes from several different mechanics or dealerships. 
• Consider a used part: Ask about the availability of used or remanufactured parts, especially for older vehicles. 
• Look for recalls or service bulletins: In some cases, manufacturers may cover the cost of certain repairs for a specific period.