How to Fix BMW DBC Malfunction? (With Step-by-Step Guide)

Are you facing a DBC malfunction on your BMW? and worried about your vehicle?

Then don’t worry, because here we’ll talk about the DBC system, the causes, and the step by step process to fix the DBC malfunction.

The DBC or Dynamic Brake Control system is found mostly in the new models.

So, let’s see how to fix the BMW DBC malfunction and its potential causes.

What Is DBC or Dynamic Brake Control?

The Dynamic Brake Control or DBC is a part of the safety feature available in the BMW, which works simultaneously with the ABS and DSC (Dynamic Stability Control) to monitor and adjust the braking power of each wheel.

In emergencies, this system improves braking effectiveness by distributing the braking force to each wheel. In emergencies with the DBC, the brakes get more efficient & effective.

The main purpose of DBC is to control the braking when you drive down a steep hill.

For example, when the driver needs to stop urgently, this system produces maximum braking power in a controlled way to stop the vehicle at the shortest distance.

This has some other features like start-off Assistance, which lets you start the vehicle in the incline without pressing the brake.

What is DBC Malfunction on BMW?

The Dynamic Brake Control (DBC) malfunction refers to when the DBC function of optimizing the braking power distribution doesn’t work properly. This malfunction causes issues in the braking system, which reduces the braking efficiency.

So, let us find out the causes & solution of this malfunction.

Possible Symptoms Of DBC Malfunction

So, other than the DBC malfunction warning light many other symptoms can give you early signs of DBC malfunction.

So, let’s check out the possible symptoms of the DBC malfunction.

• Warning Light: Firstly you will see the DBC malfunction warning light in your iDrive dashboard, other than this you could also find other yellow warnings, which are related to DBC errors.
• Start-off Assistance Inactive: With DBC malfunction the start-off assistance stopping feature will also stop, this will result in a start-off Assistance inactive warning in your dashboard.
• Unusual Braking Behaviour: When the DBC malfunctions you will experience unusual braking behavior & reduced braking efficiency. You have to press the brake on steep hill roads constantly.

Causes Of DBC Malfunction On A BMW

There can be many reasons which can cause the DBC malfunction on your vehicle. So, we have to first find out the exact cause before fixing the DBC malfunction.

1. Damaged or Low Battery Power

One of the common causes of DBC malfunction is when the battery is damaged or has very low power. And, when the battery doesn’t have much power, the first effect can be seen in DBC & DBS system failure.

A damaged or very low-power battery means it will largely affect the electronic system, where the DBC is run on the electrical system.

A battery can be damaged or have low voltage due to dirt & corrosion on the battery terminals, or it has become very old.

2. Issue With The ABS

As stated earlier the DBC system works simultaneously with the ABS, and if any issue occurs in the ABS it will largely affect the DBC system.

An internal fault in the ABS hydraulic system is often one of the most common causes of DBC malfunction.

If any issue occurs with the ABS it will disable the DBC and can also result in DSC malfunction.

This issue needs professional repair, they have the required advanced tools & expertise to repair any issue regarding the ABS issue.

3. A Dying Alternator

The alternator converts the mechanical energy into electrical energy, then it recharges the battery.

And, when the alternator is dead or weak it will cause every electrical component to stop working properly.

The major effect goes on the Dynamic Brake Control (DBC) and Dynamic Stability Control (DSC) systems because they are very sensitive to voltage.

Also Read: BMW TPM Malfunction: Reasons & Solutions (Step by Step Guide)

4. Steering angle sensor Issue

The DBC system gets important data from the Steering Angle Sensor, like if the car is going straight or turning, and if turning how sharp or low turn. Then the DBC system optimizes the braking distribution according to the data from steering angle sensors.

And, when the steering angle sensor has any issue, the DBC system will go off and show a warning in your BMW dashboard.

The same can also be caused by the misalignment of wheels in your BMW.

5. Faulty Wheel Speed Sensor

If the wheel speed sensor becomes faulty, it will cause all the braking-assisted systems to malfunction. Because the brake-assisted systems work based on wheel speed information.

Mostly, the rear wheel sensors are prone to be faulty. Before replacing the sensors always check the wirings and connectors of the sensors.

Because a faulty wiring or connector can also disrupt the data communication and cause DBC malfunction.

How To Fix DBC Malfunction?

Some DBC malfunction problems can be fixed by a DIY, but some problems can be very tricky(hard) and won’t be able to fix them.

But, here I will give most of the solutions for fixing common problems, with the ones that need professional help.

So, let’s get into the step by step process:-

1. Diagnostic Test

A diagnostic test is the easiest and most common way to find out the exact root cause of any particular issue.

So, to do this diagnostic scan you need a BMW OBD-II scanner. A scanner can easily read the malfunction codes stored in the computer of your BMW & also you can reset those codes after fixing the issue.

Here are the steps to do a diagnosis scan:-

• First connect the scanner to the OBD-II port, located under the driver’s side dashboard. (check the owner’s manual if needed)
• And on the scanner.
• Turn the ignition on. (but don’t start the engine)
• Then the scanner will give you all the information about the problem.

Now, that you know the actual problem causing the DBC malfunction, then let’s check the solutions to the problem.

2. Fixing or Replacing the Battery

If you use a scanner for diagnosis then you’ll get the information about a damaged or weak battery.

Otherwise, if you don’t have a scanner, you should always check the battery first, because this is a prime suspect for DBC malfunction.

When a battery is dying or damaged, the system cuts off power from the less needed components and gives power to the most important systems.

As you know the DBC is also not the most important system in a BMW, and it shuts off when the battery starts to die or is damaged.

You could use a voltmeter or a multimeter to check the battery power, by connecting to the battery terminals. You will also get a warning message in your BMW dashboard.

The only option here is to recharge or replace the dying battery with a professional.

3. Replacing The Alternator

If your battery power is good, then most probably the alternator is malfunctioning, because this component controls the voltage.

The alternator is responsible for controlling the voltage and supplying energy to the battery.

If the alternator dies, it will cause in lower voltage supply and the DBC system will stop working.

The only solution here is to replace the alternator, which you can do easily.

Follow these steps: Unbolt the alternator with a wrench > then remove the alternator > Install a new alternator > Bolt back.

To locate the alternator you can take help from your owner’s manual. A brand-new alternator should cost you around $140-$320.

4. Steering Angle Sensor

The Steering Angle Sensor is another reason that can cause the DBS malfunction.

If the steering wheel angle sensor is faulty, the DBC system will shut off automatically, because the DBC system relies on important information from this sensor.

The only way to fix this is to contact any professional mechanic, they will examine the sensor, and then replace it if needed.

You can not replace this sensor by yourself, because it’s a pretty complex process. The average steering angle sensor should cost up to $150-$520 & approx $200-$300 (depends) for labor costs.

5. Wheel Speed Sensor

The wheel speed sensor tracks the wheel’s speed and passes the information to all the braking and stability systems to perform their task efficiently.

And, when the sensors became faulty, it caused the DBC system to malfunction and stop working.

If the sensors are found faulty, then you should contact professional help to get the faulty sensors replaced.

6. Issue With The ABS

If the ABS is malfunctioning, then the DBC system will also malfunction.

Mainly the issue occurs with the ABS hydraulics system, and if this is also the case with you then you should take your vehicle to a certified garage.

7. Seek Professional Help

Now if you’ve diagnosed your vehicle and didn’t find any issue or can’t repair or replace the faulty component, or if you are not a DIY guy, then I would highly recommend you to seek professional help.

With more technology, the systems got more complex, which requires advanced skills.

Only a few components can be solved with a basic DIY skill.

So, it’s always better to contact your dealership or any certified Auto shop if you face a DBC malfunction issue. Because you can’t go wrong with a professional mechanic, just let them do the work.

Conclusion

The DBC system is very important in your BMW.

Any malfunction in this system will largely affect your driving, so we’ve shared every detail about the DBC malfunction.

Now you know all the common causes, how to diagnose, and solutions for the DBC malfunction.

Whenever you have a DBC issue, we would highly recommend you take your vehicle to your BMW dealership or any BMW certified Auto Shop and get this issue resolved as soon as possible and drive your BMW as before & enjoy the ride.

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