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.
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 cases, 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 of why the ESP BAS light comes on are given below:
#1. Faulty Steering Angle Sensor.
A faulty steering angle sensor is one of the most common reasons an ESP BAS light might turn on. For the ESP portion of the system to work your vehicle needs to know how much you’re turning the wheel when you’re going around a corner.
If the measurements don’t match up with the readings coming from one of the wheel speed sensors, it knows it needs to make an adjustment. But if the system recognizes that the steering angle sensor is giving faulty readings, it won’t be able to figure out what’s happening and make the necessary adjustments.
Because the actual turning of your wheels occur with a physical connection between the steering column and the rack and pinion (typically with the support of your vehicle’s power steering system), your vehicle will continue to turn even with a faulty steering angle sensor.
#2. Faulty Wheel Speed Sensor.
This is another extremely common reason your vehicle’s ESP BAS light might come on. Each wheel has a wheel speed sensor telling the computer exactly how fast that wheel is spinning. It compares those readings with the readings coming from the other wheel speed sensors to figure out if any of the wheels are slipping or losing traction.
Keep in mind if your vehicle has a bad wheel speed sensor, you’ll also lose safety features like traction control and ABS.
#3. Faulty Brake Switch.
Your vehicle’s brake switch turns on the brake lights behind your vehicle whenever you depress the pedal. This lets other drivers know you’re slowing down and allows them to react appropriately.
While brake light switches do fail (although not that often), the ESP BUS light might turn on in those cases. The reason for this is two-fold. First, it’ll turn on to let you know there’s a problem, otherwise you might not realize the brake switch even failed!
Next, the brake switch often works with the brake assist system to let the computer know you’re trying to stop. If your vehicle’s computer doesn’t realize you’re hitting the brakes it won’t know when to help you out in a hard braking situation.
#4. Wiring Problems.
All these different sensors communicate with each other and with the computer through wires, and if any of those wires aren’t transmitting accurate information this is detrimental to the system.
The problem could be a complete break in the line that’s keeping it from delivering the necessary signals, or there could be too much resistance, a short, or a crossed wire somewhere. Wiring problems are notoriously difficult to track down, but luckily they’re pretty rare.
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.
The following are the most common repairs that you need to perform to turn off the illuminated ESP BAS warning light:
- Replace wheel speed sensor
- Replace steering angle sensor
- Repair brakes
- Recalibrate the steering angle sensor
- Install new brake switch sensor
- Fix wiring issues
- Reprogram or replace the PCM
Let’s explain these repairs in detail:
#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.
- Always disconnect the battery first.
- You have to remove the steering wheel airbag by pressing on the clip installed behind the wheel.
- Bolt the steering wheel in the middle and remove the main nut with a socket and ratchet.
- Ensure the position of the wheel to see where the center is.
- As you unscrew the clock spring, you will easily see the sensor. Remove the sensor and install the new one.
- 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.
- Put your vehicle on jack stands and remove the wheels.
- As you remove the caliper, be sure to hold it somewhere, so it doesn’t cut the line.
- 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:
- Get behind the steering wheel of the car and slowly turn it left or right to lock it.
- You may also need to toggle the keys for the calibration to take effect.
- 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 OBD-II code scanner can be used to find brake switch sensor issues. This sensor is not as expensive as other sensors.
Follow the below-given steps to replace the brake switch sensor:
- The brake switch sensor is located just above the brake pedal.
- Remove the bad sensor and install the new sensor.
- 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.
| Part | Cost |
|---|---|
| ABS Pump replacement | $290 to $1100 |
| Wheel Sensor replacement | $190 to $260 |
| Brake Pad replacement | $100 to $310 |
What Sensor Does ESP Use?
Many sensors work with the Electronic Stability Programme (ESP), such as the 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.
FAQs.
What does it mean when your ESP BAS light comes on?
The ESP/BAS light indicates that there is an issue with your Electronic Stability Program (ESP) and/or your Brake Assist Program (BAS). These safety systems work together, and a fault in either, or both, will cause the trouble light to come on.
Is it okay to drive with the ESP BAS light on?
While your vehicle will continue to run with an illuminated ESP BAS light, it’s best not to ignore it. Driving with a malfunctioning ESP or BAS system can be dangerous in rainy or snowy weather.
Can I still drive with ESP light on?
The customer does not need to take any further action and can continue driving. If the ESP light is on continuously (and the ESP/ESC system is not switched off), you should contact your Volkswagen Retailer to have the system checked.
Is ESP warning light serious?
The ESP warning light indicates that an issue that needs attention. Here’s what you should do: Slow down: since the ESP helps with vehicle stability, it’s best to slow down, especially if road conditions are poor. Get it checked: at your earliest convenience, take your vehicle to a professional mechanic.