What Causes ABS Light To Come On? | How To Reset ABS Light?

Modern vehicles contain different latest technologies to improve functionality. An Anti-lock Braking System (ABS) is most commonly used in the latest cars. When something goes wrong with the ABS system, the ABS light starts to illuminate on the vehicle’s dashboard.

ABS Warning Light, how to reset ABS light

The ABS system offers improved stability and control by preventing wheels from locking while braking quickly. Upon starting the car, the ABS light will illuminate as part of a self-test routine. If this test detects no problems, the light will turn off automatically.

To avert wheel lockup, the ABS system of your car consistently tracks the speed of each wheel by using an ABS sensor and modulates the brake pressure directed to individual wheels whenever needed. This article explains the ABS light causes and how to fix it.

What does the ABS light mean?

An illuminated ABS light indicates a problem with the ABS (anti-lock braking system) of your vehicle. The primary function of the anti-lock braking system is to improve car control by preventing wheel locking while braking hard.

ABS light

Reasons for the ABS light coming on can include a damaged ABS hydraulic unit, issues with the ABS control module, or a malfunctioning ABS sensor.

This warning light is located on the vehicle dash. It typically displays as a circular symbol with the letters “ABS” inside, often in orange, yellow, or red. While its appearance may differ from other warning indicators like the check engine light, it’s commonly identified as a separate red or yellow warning light.

In response to the illuminated ABS light, it’s advisable to find a safe spot to pull over the vehicle, turn off the ignition key, and then restart it. This prompts the vehicle’s main computer to inspect all sensors of the ABS system for an issue. Sometimes, a basic reset might extinguish the light, similar to rebooting a computer.

Nevertheless, addressing the issue isn’t always as straightforward, as there could be an underlying system malfunction requiring diagnosis. The recommended approach is to contact a skilled technician who has the necessary diagnostic scan tool to assess any stored trouble codes.

Causes of the ABS Light

The efficient working of the ABS system is very crucial to prevent a vehicle from accidents. When there is something wrong with the ABS system, the ABS light starts to illuminate on the dash.

A bad wheel speed sensor or a faulty ABS module is one of the major reasons of the ABS warning light illumination. This light may come on due to a bad ABS blown sensor, damaged wiring, insufficient brake fluid, a faulty ABS tone ring, or bad ABS pump.

Let’s discuss the most common causes of the ABS light illumination:

1) Faulty ABS Wheel Speed Sensor

ABS Sensor

A bad wheel speed sensor is one of the major causes of ABS light illumination. This sensor gauges the wheels’ movement speed and transmits this data to the ECM (Engine Control Module) of the vehicle.

Based on the input data of the wheel speed sensor, the ECM makes decisions regarding ABS usage. If there’s a variance in wheel speeds, indicating uneven movement, the ECM adjusts brake fluid distribution to regulate wheel speed and boost tire traction.

However, when the ABS sensor malfunctions, it starts to send wrong information to the ECM. This not only triggers the ABS light but also leads to traction lose during abrupt braking. Additionally, the traction control light might activate.

The ABS wheel speed sensor is located near the vehicle wheels to measures their speed. This proximity, however, exposes it to substantial wear due to its location near the brakes and the heat generated. Furthermore, the sensor can be harmed by metallic fragments or dirt originating from the braking system.

Read More: Bad Wheel Speed Sensor Symptoms and Causes

2) Faulty ABS Control Module

ABS Control Module

The ABS control module can potentially experience malfunctions. The efficient working of the ABS module is very important for the efficient working of the system.

Whenever it fails, it doesn’t properly control the functionality of the ABS system and leads to different problems and ABS light illumination. It may cause reduced brake responsiveness. Initially, this might manifest sporadically but tend to worsen over time. There’s also a possibility of brake lockups occurring or the occurrence of clicking sounds.

3) Faulty ABS Tone Ring

ABS Tone Ring

The wheel speed sensor relies on the ABS tone ring to gather wheel speed data. In certain instances, the ABS ring might corrode or develop fractures, leading the ABS sensor to provide inaccurate readings. This situation prompts the illumination of the ABS light.

Certain ABS rings are situated within the wheel bearing assembly, necessitating the replacement of the whole bearing unit. But when the ABS ring is positioned on the driveshafts, it’s often feasible to visually check it for cracks or other damages.

4) Damaged Wiring

An issue with the wiring connected to the ABS system may also trigger the ABS light. These wires are susceptible to corrosion, leading to communication delays or failures between the ABS sensor and the ABS module.

While repairing the wires would be a preferable and cheap solution.

5) Blown Fuse

ABS Fuse, reasons of ABS light illumination

The functionality of the ABS system relies on the electrical components within your vehicle, and it operates using a dedicated fuse. However, this fuse is susceptible to failure and can blow unexpectedly.

Fortunately, checking the fuse is a relatively simple task. If you’re only observing the ABS light illuminated on the dashboard without any other symptoms, inspecting the fuse might be the initial step in the diagnostic process.

6) Bad Hydraulic Pump

The ABS system plays a crucial role in regulating brake fluid flow by using a hydraulic pump. The hydraulic pump propels brake fluid into the brake cylinder, which then disperses it to the brakes upon depressing the brake pedal.

Moreover, the anti-lock braking system fine-tunes the pressure of the brake individually for each wheel, using input from the ABS sensor. This ensures optimal fluid delivery to the brakes where it’s highly required.

While the ABS system generally functions as normal, potential issues can arise. The hydraulic pump may become faulty, or a faulty valve within the hydraulic system could occur—both of which are problematic. This pump can be prone to wear due to contaminants like dirt and metal shavings from compromised brake fluid. Regular fluid changes can help prevent such problems.

An issue with the hydraulic pump can lead to compromised braking performance. The decline might begin slowly and escalate if left unaddressed.

In cases of master cylinder failure, brakes could initially feel normal but suddenly lose all power, posing a serious driving hazard. Additionally, defects might cause fluid leaks. When fluid leaks occur, the pedal could initially remain firm but gradually become spongy, ultimately sinking to the floor.

7) Insufficient Brake Fluid

Brake Fluid Level, causes of ABS light

For the proper operation of the ABS pump, an adequate supply of brake fluid is essential. The brake fluid is pumped by using a cylinder in the brake system. Insufficient brake fluid levels can lead to various problems, including the potential activation of the ABS light.

When encountering low fluid levels, it’s crucial to identify the underlying cause. Possibilities include worn brakes, air trapped in the brake system, damaged seals, or a leak in the brake fluid reservoir.

Allowing the fluid to drop excessively can cause the ABS module to lose its ability to balance pressure among the wheels, leading to slipping and skidding.

As brake fluid levels continue to decrease, braking effectiveness might diminish, and increased noise during braking could also become noticeable.

How To Reset the ABS Light?

When your vehicle triggers the ABS light, it is very important to fix it as soon as possible to prevent your engine from damage. Follow the below-given methods to reset the ABS light:

  • Turn off the vehicle engine and let it cool properly.
  • Start by disconnecting the positive terminal of your car’s battery. Afterward, firmly press the brake pedal to deactivate the vehicle’s electrical system. This action will prompt a reset of the central computer. Reconnect the terminal of the battery to restore power. This process should reset the ASBS light, assuming the system is trouble-free.
  • If the ABS again start to illuminate, ensure the proper inspection of the ABS fuse. It is usually located under your vehicle dashboard. It is recommended to consult the owner’s manual to find the exact location of the fuse.
  • Assess the brake fluid level. If it’s insufficient, top it up. In case the fluid appears contaminated, draining and refilling is recommended.
  • Conduct a thorough leak check. Look under your vehicle for signs of leaking brake fluid. Healthy fluid exhibits a light-yellow hue, whereas dirty fluid usually has a slightly dark color, even appearing brown.
  • Utilize a voltmeter to test the ABS wheel sensor. Alternatively, you may employ an OBD2 scan tool to retrieve trouble codes, which should pinpoint any faults in the system.

Is it Possible To Drive With ABS Light?

Driving with the illuminated ABS light is not recommended, as it signifies an issue with the ABS system. The ABS system of a vehicle is designed to avoid wheel lockup and improve braking performance in critical situations.

When the ABS system becomes faulty, it will not work as efficiently as it should, potentially leading to reduced control while heavy braking. This may result in longer stopping distances and a heightened risk of accidents.

Additionally, continuing to operate the car when the ABS warning light is active could cause further harm to the ABS system and other associated parts. Therefore, it is not recommended to drive with an illuminating ABS warning light.

It is recommended that upon observing the ABS light, you promptly have the system inspected and repaired to ensure both your safety and the proper functioning of your car.

Moreover, driving with the illuminated ABS light might lead to the invalidation of your vehicle’s warranty. Thus, addressing the issue promptly is essential to prevent potential complications.

How to Fix ABS Light

The cost to fix the ABS light can range from $25 to $1,000, contingent upon the underlying cause of the illumination.

While I’ll delve into the typical repairs associated with addressing the ABS light, it’s crucial to engage in a comprehensive diagnosis first to accurately pinpoint the root of the issue. This ensures that you don’t unnecessarily replace components that aren’t faulty.

Among the more affordable fixes is addressing a blown fuse, which should generally amount to $25 or less. Furthermore, rectifying this particular problem is relatively straightforward.

FAQ Section

What is the ABS light on in a Toyota?

When the ABS light illuminates on your Toyota car’s dashboard, it indicates an issue with the vehicle’s ABS system.

What is the function of ABS in a car?

The primary function of ABS is to avert skidding caused by wheel lockup during hard braking, ensuring that steering and control are maintained. This safety feature is now a common inclusion in many modern car models. Its purpose is to enhance emergency steering capabilities rather than to reduce braking distances.

How long can you go with the ABS light on?

Driving with an illuminated ABS light is strongly discouraged, particularly if you’re not accustomed to driving vehicles without ABS. However, even if you’re experienced with non-ABS vehicles, it remains essential to identify the root cause of the issue. Seeking prompt diagnosis and repair from a mechanic is advisable.

Can low brake fluid cause the ABS light to come on?

Absolutely, insufficient brake fluid may activate the ABS light. Insufficient brake fluid may potentially lead to a loss of pressure within the ABS pump, triggering the activation of the ABS system’s limp mode. This situation prompts the ABS light to become illuminated.

Is it safe to drive with the ABS light on?

While the ABS light is illuminated, it is advisable to drive cautiously, but it is important to promptly schedule a diagnostic check. Your standard braking function remains unaffected even with the ABS light on, allowing you to continue driving. Nevertheless, it’s not advisable to drive without the ABS system, as it contributes significantly to braking control.

What causes the ABS warning light to come on?

There are different reasons for the ABS light to come on, such as a bad ABS sensor, a faulty ABS tone ring, insufficient brake fluid, damaged wiring, a bad ABS pump, faulty wheel bearings, an issue with the ABS module, or a blown fuse of the ABS system.

Can a faulty battery cause ABS problems?

Although ABS problems due to a weak battery can occur, such instances are relatively infrequent. Typically, other vehicle malfunctions are more likely to manifest before attributing issues to a faulty battery. However, if you are experiencing ABS-related complications, it’s a prudent step to investigate the battery’s condition as a potential contributor.

What causes ABS to fail?

An Anti-Lock Braking System (ABS) may become faulty due to various reasons such as a bad ABS sensor, insufficient brake fluid, damaged wiring, dirty brake fluid, bad ABS pump, an issue with the ABS module, blown ABS fuse, mechanical fault, or electrical issues.

Can a bad ABS turn on the check engine light?

Yes, an issue with the ABS system can trigger the check engine light. If a problem arises within the ABS system, it could lead to the illumination of the check engine light, possibly prompting the storage of a fault code within the engine control module. It’s important to recognize that instances leading to the activation of the check engine light may occasionally stem from factors unrelated to the ABS system. To accurately pinpoint the origin of the issue, it is recommended to undergo a diagnostic scan.

Can you fix the ABS sensor?

Should your ABS sensor prove to be malfunctioning, replacement becomes a necessary course of action. The reason is that a defective ABS sensor has the potential to compromise the functionality of your ABS system, particularly at critical moments. While replacing an ABS sensor is not an overly complex procedure, it’s best entrusted to a skilled mechanic.

Can worn brake pads cause the ABS light to come on?

Yes, in some cases, the worn brake pads can trigger the ABS light. Worn brake pads deplete your brake fluid. By doing this, they can trigger your car’s ABS light.

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