ESP BAS Light Meaning and Causes | How to Fix ESP BAS light?

ESP stands for Electronic Stability Program. In the case of some vehicles, the ESP is called Electronic Stability Control. The vehicle dashboard contains multiple warning lights and symbols that let you know if something goes bad. When you see an ESP BAS warning light on the car’s dashboard, it’s important to understand what it means and why. This article explains what the ESP BAS light means, its causes, and how to fix it.

What does the ESP BAS Light Mean?

The ESP BAS light is a warning light on the vehicle’s dashboard that indicates two things: ESP and BAS. The ESP BAS light indicates an issue with your vehicle’s Brake Assist System or Electronic Stability Program.

This light works like any other warning light located on the dashboard to alert you to a problem.

ESP BAS Light

The ESP BAS light works on a variety of issues, from minor to major. As with any major vehicle problem, you may get a diagnostic trouble code. In such case, use a good quality code scanner or take it to your local auto repair shop and ask the mechanic to scan it.  

What causes ESP BAS Light to come on?

When your car’s warning light comes on, it means that something is wrong. Illumination of the ESP BAS light indicates a malfunction of the Brake Assist System or Electronic Stability Program.

The most common causes why the ESP BAS light comes on are given below:

  1. Bad wheel speed sensor
  2. Faulty brake switch
  3. Bad steering angle sensor
  4. Damaged or faulty wiring
  5. Bad brake pads and calipers

1) Bad Wheel Speed Sensor

Each wheel on the car has a speed sensor that assists in determining the wheel speed and transmits it to the ESP/BAS system. When ESP and BAS systems detect that the car wheels are rotating at diverse speeds, they correct the speeds so that all wheels move at the same speed, allowing you to hold the car tightly.

Wheel Speed Sensor

If the wheel speed sensor is missing or has failed, the ESP BAS light with Traction Control Light will illuminate to alert the car driver. A bad sensor can be a disaster, especially on slippery roads, so keeping it is not a mistake but should be repaired instantly if found.

2) Faulty Brake Switch

Whenever you apply the brakes to slow down your vehicle, the brake light at the back of the vehicle will light up. This light informs the following vehicles that they can also slow down or leave the lane behind your car because you have pressed the brake to reduce your car speed.

Faulty Brake Switch

The brake switch is the electrical switch in the braking system responsible for turning on the brake lights. If the brake switch fails or is not working properly, the vehicles behind you may not recognize that you have pressed the brakes due to that they may collide with your vehicle, which is extremely dangerous.

Due to the position of the brake lights, it’s impossible to tell if the brake lights are working properly, so the car designs a way to turn on the ESP BAS light to let you know. Therefore, your ESP BAS light may come on due to a bad brake switch.

3) Bad Steering Angle Sensor

The latest cars are equipped with sophisticated sensors, for example, for the steering angle. A faulty steering angle sensor is one of the most common reasons why the ESP BAS light comes on.

Steering Angle Sensor

This sensor aligns the steering wheel with the wheels of your vehicle. Using this sensor, your vehicle knows which direction to turn the steering wheel based on the input provided by the steering angle sensor.

The steering angle sensor moves the wheels in response to the steering. If you turn the steering wheel to the right, the steering wheel follows you and rotates the steering wheel to the right.

If this sensor fails or isn’t working properly, it can send false data to your wheels, which can cause your car to make wrong turns, hit other cars spin, or swerve over the road.

As the steering angle sensor goes bad, your ESP BAS light immediately comes on. A faulty sensor can be repaired by turning the steering wheel right twice, then left twice, before returning it to the center. If that doesn’t work, drive your car to a workshop.  

4) Damaged or Faulty Wiring

There are multiple wires between ABS control modules and different sensors. The ABS wheel speed sensor wire is attached to the wheel and gets damaged from time to time.

The wires are usually well protected, so less so with newer models, but it can happen if you’re unlucky. The bad thing about wiring issues is that they can be very difficult to find if you are not experienced.

5) Bad Brake Pads and Calipers

Worn brake pads cannot grip your car’s wheel properly. Likewise, a defective brake caliper does not exert sufficient pressure on the brake pads. These issues badly affect your car’s braking system and turn on the ESP BAS light.

Bad Brake Pads and Calipers

How to fix ESP BAS Light?

The easiest way to determine what caused the ESP BAS light to come on is to read the trouble code with an OBD2 scanner on your car’s ABS control module. This will help you find the problem or fix it instead of guessing and swapping parts.

Following are the most common repairs that can fix the illuminated ESP BAS warning light:

  1. Replace wheel speed sensor
  2. Replace steering angle sensor
  3. Repair brakes
  4. Recalibrate the steering angle sensor
  5. Install new brake switch sensor
  6. Fix wiring issues
  7. Reprogram or replace the PCM

1) Replace Wheel Speed Sensor

As we discussed above, a bad wheel speed sensor is one of the major causes of the illuminated ESP BAS light. This wheel sped sensor is located behind each set of brake discs. Replacing a faulty sensor is relatively easy due to easy access, but it can become clogged with rust.

Jack up your car and remove the affected wheel. Once the sensor is removed, you can simply install a new sensor.

2) Replace Steering Angle Sensor

If wheel speed sensor replacement does not fix the problem, then you need to replace the steering angle sensor if needed. Fortunately, the steering angle sensor replacement process is very easy; just use a ratchet and socket wrench.

  1. Always disconnect the battery first.
  2. You have to remove the steering wheel airbag by pressing on the clip installed behind the wheel.
  3. Bolt the steering wheel in the middle and remove the main nut with a socket and ratchet.
  4. Ensure the position of the wheel to see where the center is.
  5. As you unscrew the clock spring, you will easily see the sensor. Remove the sensor and install the new one.
  6. Plug everything in and start the vehicle. Also, the system needs to be recalibrated to turn off the lights.

3) Repair Brakes

Repair the issues related to your car’s brakes, and then check if the lights go out.

  1. Put your vehicle on jack stands and remove the wheels.
  2. As you remove the caliper, be sure to hold it somewhere, so it doesn’t cut the line.
  3. Now, remove the rotor and change it if necessary. If you still have enough material, resurfacing is recommended. Replacing brake pads is also not difficult.

4) Recalibrate the Steering Angle Sensor

In some cases, you may just need to recalibrate the steering angle sensor. This can be done on driveways without any specific tool.

Follow the below-given steps to recalibrate the steering angle sensor:

  1. Get behind the steering wheel of the car and slowly turn it left or right to lock it.
  2. You may also need to toggle the keys for the calibration to take effect.
  3. Sometimes, an OBDII scanner can recalibrate the steering angle sensor. Read the code and adjust it if necessary.

5) Install New Brake Switch Sensor

An OBDII code scanner can be used to find brake switch sensor issues. This sensor is not much expensive as other sensors.

Follow the below-given steps to replace the brake switch sensor:

  1. The brake switch sensor is located just above the brake pedal.
  2. Remove the bad sensor and install the new sensor.
  3. Reset the code that is set to turn off the ESP BAS lights.

6) Fix Wiring Issues

There are multiple wire connections between the ABS control module and other sensors. Your car’s ABS wheel speed sensor wires run through the wheel and can become damaged.

Wiring is very complicated, and any mistake can cause other big problems, so take your car to an experienced auto electrician to fix the problem.

7) Reprogram or Replace the PCM

The powertrain control module (PCM) is known as the brain of the vehicle. It takes data from different engine sensors and uses this data to control the vehicle’s performance and different parts. A bad PCM may turn on the ESP BAS light. In such a situation, replace or reprogram your PCM.

Read More: Bad PCM Symptoms and Causes

How much does it cost to fix the ESP BAS light?

The fixing cost of the illuminated ESP BAS light depends on the cause of the problem and labor cost.

PartCost
ABS Pump replacement$290 to $1100
Wheel Sensor replacement$190 to $260
Brake Pad replacement$100 to $310

FAQ Section

What does ESP mean on a car?

The ESP stands for Electronic Stability Program. It is a computerized safety technology found in the latest vehicles. This technology is introduced to detect and mitigate the loss of traction to improve vehicle stability and prevent uncontrolled tire skids.

Can I drive with illuminated ESP BAS light?

Avoid driving with the ESP BAS light on, as it is dangerous. To ensure safety, this issue must be addressed immediately. It can be mild or severe.

A bad ESP system can lead to tragedy. A grip is needed to keep the car on the road. If these sensors fail, you risk losing grip on tight turns and snow.

Where is the ESP sensor located?

The ESP sensor is installed in the engine compartment. The powertrain control module (PCM) takes over the electronic and electrical tasks as well as all control functions of the system.

What does ESP BAS mean on your car?

The ESP BAS light covers the Electronic Stability Program (ESP) and Brake Assist (BAS). The ESP and BAS work together, and the lights come on if one or both fail. If it still lights up, contact a professional.

What would cause the ESP BAS light to come on?

The ESP BAS light represents an issue with the vehicle’s Electronic Stability Control or Brake Assist program. Common causes of this light include a bad steering angle sensor, a wheel speed sensor failure, a brake switch failure, bad PCM, or some other braking system failure.

What is the difference between the Traction Control light and ESP BAS light?

The traction control light indicates that the vehicle’s traction control is in use. This indicates that the vehicle has temporarily lost traction when turning into tight corners or when driving on wet roads. Rather, the ESP BAS light indicates a problem with the vehicle’s electronic stability program or brake assist program.

What sensor does ESP use?

Many sensors work with ESP, such as brake switch, wheel speed sensor, steering angle sensor, and other sensors associated with the vehicle’s braking system.

ABS is a vital part of your car as it supports the functioning of the braking system. The ESP BAS light comes on when there is a problem with the traction control system.

Is ESP important in a car?

ESP is one of the most important safety features for vehicles as it stops or at least lessens the effects of slipping. While driving, the ESP continuously check different information such as steering angle and the speed of the car wheels.

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