What Causes DBC to Malfunction on BMW? [Diagnosis & Fix]

What Causes DBC to Malfunction on BMW? BMW features Dynamic Brake Control or DBC in them. You may only get the importance of the BDC after it causes an error. This built-in DBC system in your BMW might malfunction and fail to adjust the braking power.

A DBC malfunction in a BMW can have many causes. It is usually caused by a dying battery or an alternator. A broken wheel speed sensor and steering angle sensor are two additional significant causes of this malfunction in a BMW. Apart from that, faulty ABS module issues also cause this trouble.

I have compiled all the causes that lead to the DBC malfunction in a BMW here. In this article, you will also learn to diagnose these issues and find the fixes for each of those problems.

What Is The DBC System, And How Does It Work?

The DBC is a short form for the Dynamic Brake Control System, which ensures that the BMW gets enough braking power to stop in times of emergency. 

The DBC system always monitors each wheel and their supplied braking powers. This system tweaks and adjusts the power needed to pull the brakes when necessary. 

It often comes into action while going down a very steep hill. Under such circumstances, the system works by supplying the maximum power to stop the BMW on short notice. 

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Symptoms of BMW’s DBC malfunction 

When the DBC malfunctions in the BMW, you may notice the following symptoms manifest. Once you notice any of these, take the necessary step to fix the issue. 

  • Turn on the yellow light when the DBC malfunctions. 
  • In some of the BMWs, you might also see a message saying malfunction on the display screen.
  • The Start assistance will show an inactive alert.
  • You will need to pull the brakes a lot more often while driving. Especially if you have to go down a steep hill, you might need to put extra strain on your brakes.

Causes And Fixes Of DBC Malfunction On BMW

Here is a list of problems that lead the DBC system to malfunction on a BMW. Trying to fix the DBC malfunction on your own is not recommended. Most of the fixes for this problem are extremely difficult and require professional help.

1. Bad Battery

One of the most probable causes of the DBC malfunction is the battery going bad or dying. An almost dead battery fails to hold a charge and supply the necessary power to all the components. 

As a result, the power source to the DBC system cuts off, and the system shuts down. 

The battery of a BMW can also accumulate dirt and erode over time. This also ends up as a bad battery and stops the DBC system from working. 

Solution: Replace the Battery 

A dying battery can only be fixed perfectly by swapping it with a new one. Firstly, use a multimeter to check the voltage of the battery. If it is too low, try charging the battery properly. 

If the battery still fails to hold a charge, replace the battery with a new battery. Make sure the new battery you purchase fulfills the voltage requirements of the BMW operations.

Read Also: Why BMW Lane Departure Warning Malfunction? Causes & Fixes

2. Faulty Alternator

The DBC system gets affected by an alternator. Such an alternator fails to regulate the correct voltage inside the DBC system. As this system is extremely voltage-dependent, lack of proper voltage causes it to stop functioning. 

Solution: Install A New Alternator

An alternator does not have a chance to be alright after charging it. So, the only way to fix it is to install a new alternator in your BMW. With some experience, you can do this replacement on your own. 

Use proper tools to get the damaged alternator out and install the new one in its place.

3. Broken Wheel Speed Sensor

The BMW wheel speed sensors store and relay information about the wheel speed to the braking systems. This sensor decides when to use the braking system when the BMW is too fast. 

Once this wheel speed sensor is broken, it stops transferring information about the wheel speed. 

As a result, the DBC system fails to engage without this sensor. The sensor can break due to damage, bending, or corrosion.

The wheel speed sensors need a replacement once they are broken. You can’t fix a broken sensor by mending it. So, it is better to take the BMW to a repair shop and get a new wheel speed sensor installed correctly.

Read Also: BMW Passenger Restraint System Malfunction: Reasons & Fixes

4. ABS Hydraulic Module Problem

The ABS controls the DBC(Dynamic Braking Control) and the DSC (Dynamic Stability Control). 

If the hydraulics in the ABS stops working, it directly affects the DBC system. The ABS can be broken for it to cause the DBC to terminate.

This fix requires the touch of a professional. Therefore, take the BMW for a checkup and get the hydraulics fixed with their help.

5. Misalignment of The Steering Angle Sensor 

The steering angle sensor notifies you about the steering wheel’s angle at that moment. This sensor alerts the DBC system of what angle the BMW is going forward. 

When the sensor gets misaligned from its usual place or faces a defect, it stops the DBC from engaging as well.

For fixing the steering angle sensor, it is recommended to use a scanner or take the BMW to a professional first. If the issue with this sensor is fixable, the repair shop will complete the fix. 

However, if it is beyond fixing, you might also need to replace this sensor. This is a really expensive sensor, so be sure you need it before purchasing a new one. 

6. Error Codes 

If you can’t diagnose the exact cause of the malfunction, you will need to scan the BMW for certain error codes. Each error code stands for a specific problem referred to in the manual. 

So, once you find out the related issue with the error code, you can fix that one problem easily.

You will need to use an OBD2 scanner to determine the error codes. Purchasing this scanner might be too expensive to handle. So, just take the BMW to a repair shop and get the scan done. 

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Hopefully, you get the answers to some of the most popular questions regarding the DBC system of BMW and its malfunction. This segment will clear up all the residue doubts in your mind.

How Do I Know The DBC System Is Malfunctioning?

The warning lights will tell you that the DBC on BMW is malfunctioning. The warning lights will be illuminated on the dashboard to instantly alert you of the malfunction. So, you better keep an eye on those warning lights.

What Is The Cost Of Fixing A DBC Malfunction On BMW?

The cost of fixing the DBC malfunction depends on the component you need to replace. Replacing the battery will cost you around $250. An alternator will cost you $300, and a steering angle sensor will cost $500. The labor cost can go up to $250-$300.

What Is A DBC Error Code On BMW?

If you can’t pinpoint the exact cause of the DBC malfunction, you need to run a diagnostics test using a scanner. This scanner will recognize an error code and evaluate the exact cause of the malfunction. The error codes indicate specific reasons, which you can fix accordingly.

Is It Safe To Drive When The DBC System Is Malfunctioning?

No, driving the BMW is unsafe while the DBC system is not working. The braking system of BMW will be less efficient in such circumstances. As a result, the BMW might be unable to stop while driving at high speed or down steep hills. It increases the chances of accidents and damage to a great extent.

Read Also: BMW TPM Malfunction? 6 Reasons Why


As the owner of a BMW, no one does not appreciate the added privilege of the Dynamic Braking Control system. This system largely helped all the drivers of BMW to control the car at times of emergency. 

Driving down a steep hill or at high speeds has become reassuring because of this helpful feature. As I have suggested, it is always better to take the BMW to a skilled repair shop for fixes rather than doing it yourself. 

The process may be costly, but it will be worth it in the long run for your safety. If you can’t fix the issue immediately, avoid driving to high places for the time being. Engage brakes earlier than you are used to until the DBC is completely fixed.

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