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BAS ESP ABS Mercedes-Benz

BAS / ESP / ABS warning lights stay on?

The BAS / ESP / ABS lights is not a problem with just Mercedes-Benz ML320 / ML430 models. It is a problem that has impacted all Mercedes-Benz models. We have included the top causes that trigger these lights to come on in the section below. This guide could save you hundreds of dollars.  Learn how, you may be able to turn off these lights by following a few simple steps.

What does BAS ESP ABS light mean on a Mercedes-Benz?

Let’s first take a look at what each of these acronyms means.

ML320 BAS ESP ETS LIGHTSBAS stands for Brake Assist System. It provides additional braking power in case of emergency situations.

ESP stands for Electronic Stability Program. It helps as you drive by braking individual wheels or reduce engine torque output.

ETS stands for  Electronic Traction Support. It stops the wheels spinning under hard accelerating conditions or on low traction surfaces.

ABS stands for Anti-Lock Braking System. It helps you avoid skidding during emergency stops. It ‘s okay to feel pulsing on the brake pedal. The ABS light should only be on for a few seconds when you turn on the ignition and when it is activated it may flash briefly.

Top 5 reasons for BAS / ESP / ABS light is staying on.

BAS ESP ABS systems work together. If one of the systems has a problem, then you may see several other lights turn on. That’s because they depend on the failed system.  Here is what you should do if you have any of these lights on.

Try this Simple Fix

If your battery died or you recently replaced the battery, there is a good chance the ABS/ ESP / BAS lights are illuminating on your instrument cluster. To reset the lights, start up your Mercedes-Benz and turn the steering wheel all the way to the right, then all the way to the left. Do this a couple of times. Turn off the engine. Restart.

Brake Light Switch may cause BAS / ESP / ABS light to come on.

It is the most common problem with Mercedes-Benz cars. Very familiar with models such as E 320, C 240, SLK, CLK and several other Mercedes-Benz chassis. Luckily for you this is a very easy repair that you can also perform yourself. All you need is a Brake Light Switch for your Mercedes-Benz model. You can find brake light switch on Amazon for any Mercedes-Benz at a fraction of dealer prices.

Where is the brake light switch and how to replace it yourself?

The brake light switch is located right above the brake pedal. Replacing the switch is easy. You can follow this guide on How to Replace the Brake Light Switch on a Mercedes-Benz. 


Older batteries can also cause the BAS / ESP lights to come. As the battery gets older it can no longer supply the required voltage to your car’s control units. If you had to connect your vehicle to a diagnostic scanner, you would find several Undervoltage Fault Codes stored. A battery that is not performing as expected could also cause other problems such as Warning Light in Dash. Car stuck in gear also known as the limp mode or other unpredicted problems.

If your battery is over five years old, you should consider replacing the battery in your Mercedes-Benz. Don’t wait until you get stuck. Jump starting Mercedes-Benz cars is never a good idea, unless you absolutely have too and know how to do it correctly. Replacing the battery is very easy. Remove the two battery terminals by loosening the 10 mm bolts. Remove the 13 mm bolt on the bracket that holds the battery in place. Install the new battery in reverse order.

If you decide to replace the battery on your Mercedes-Benz, make sure to replace with a compatible battery. Mercedes-Benz typically uses Group 49 battery. You will find some of the best prices on batteries for Mercedes-Benz on Amazon. Look for Group 49 Sealed AGM Battery.


ABS wheel speed sensor

If you have an ABS sensor that has failed, it will also trigger the ABS, ESP, BAS light. Because the ESP system depends on the ABS system to function properly, the ESP system will also get disabled. A faulty ABS sensor could cause other issues as well such as Check Engine Light, car not moving when in Drive, speedometer not working. Each of the four wheels has a ABS sensor. They are not difficult to replace. A quick search online yielded many choices on Mercedes-Benz ABS sensors some as low as $30, but the actual price depends on the Mercedes-Benz Model that you have.


ABS/ESP Module

The ABS / ESP control module read the speed data from several sensors including the ABS wheel speed sensors and clock spring. The ABS module or in some models the SBC Brake module will apply pressure to the brake pads at each of the individual wheels depending on the directions it receives from the vehicle’s control units. While it is less likely to fail, it is known to be a problem as well. Replacing the ABS Module can be costly.  If you are brave, you can open the ABS pump and check if the brushes are worn out and replace them. A guide on how to do that can be found here.


If any of the lights BAS/ESP/ABS have come on, try the steering wheel calibration first. If that doesn’t fix the problem, consider replacing the Brake Light Switch as they are very inexpensive, and it’s a repair you can do yourself. You can follow this guide on how to change the brake light switch.

If the brake light switch doesn’t fix the problem, you should not replace any other parts without finding out the real reason for the light coming on. Get a hold of a diagnostic scanner and connect it to your car. In minutes, you will know the reason the ABS / ESP / BAS lights are on. A diagnostic scanner will help you pinpoint your problem which could be a variety of other possibilities such as the clock spring, MAF sensor, relay, fuse, continuity issue to name a few. You have the option of taking the car to a repair shop and get charged $100+ for it. You may as well look into getting a diagnostic scanner for not much more. Consider doing this troubleshooting part yourself, even if you don’t do the repair.

If you go this route, we would recommend taking a look at our review of Top 10 Diagnostic Scanners for Mercedes-Benz cars.


  1. The ABS light has been on in my 2004 S430 4matic since June 2017. The local dealer had it for 3 months and concluded the drivers side rear wheel sensor is bad. They tried new sensors part # 2205400417 from MB and other vendors but none worked. They told me I need to find a used sensor from a 2004 S430 4matic and that should clear the ABS light. I have tried 2 used sensors that the seller said came from 2004 S 430.

  2. Hi I have the same issue on W210 ESP BAS light on… the situation is this:
    1) My battery (Amaron Pro) has been replaced in Jan 2017 and by far I drive about 1000km only.
    2) If the car stop the engine for 1-2 day, the ESP BAS (Sometimes SRS also) light on.
    3) Once I see these lights, I let the engine run for 1-2 minutes, then turn off.
    4) Then I restart the engine again, the lights off with No malfunction.
    5) After this, these lights won’t light no matter how long you drive and how many times you start the engine.

    I have tried reset the sensor by turning left/right on wheel for a few times, the same situation re-appear above.

  3. tank’s for all of your help hope replacing the brake sw. helps

  4. It didn’t come on until I was parked on incline and had to go over dip in driveway- very sharp one. Dirt section of driveway not gravel. It was also raining and muddy

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