Fix Mercedes-Benz C 300 Auxiliary Battery Malfunction

If you were having an issue with your vehicle, you may be wondering how to fix Mercedes-Benz C 300 auxiliary battery malfunction.

As this is a common Mercedes-Benz issue that can’t come up for vehicle owners.


If this happens to you, you will probably want to try to fix the issue yourself, as it can be costly to have a professional do it for you. Though you will need to have some auto experience to tackle this project.

It is important to fix any kind of malfunction with your vehicle as it is not safe to continue to drive it. Any kind of malfunction can become more severe if you ignore it and do not fix the issue as quickly as possible.

Keep reading to find out more about how to fix Mercedes-Benz C 300 auxiliary battery malfunction and what to expect.

Fixing a Mercedes-Benz C 300 Auxiliary Battery Malfunction

If you own a Mercedes-Benz C 300, you may eventually find yourself in the position of needing to fix an auxiliary battery malfunction. This can be difficult as you will need to locate the battery, remove it, and replace it with a new battery.

There are different Mercedes-Benz models, so you will need to figure out where exactly the battery is located in a C 300 Mercedes. Which can be more difficult than you would think, so you will want to do your research beforehand.

When you have an auxiliary battery malfunction, your Mercedes-Benz is going to be greatly affected as you are going to get all kinds of errors. This affects the electrical side of your Mercedes-Benz and can affect a lot of the features.

This cannot only make it difficult to drive but make it unsafe as well. As these features are there for a reason, and if they are displaying incorrect errors, you will not be able to know if you have other issues with your vehicle.

That is why, you should fix a Mercedes-Benz C 300 auxiliary battery malfunction as quickly as possible. Whether you decide to do this yourself or take it in to have a professional fix the battery for you.

Locate the Battery

Before you start working on this vehicle repair, you are going to need to locate the battery and your Mercedes-Benz C 300. This battery is going to be located under the cabin Air filter housing under the hood.

You will need to remove the cabin air filter housing in order to get access to the battery underneath it. Once you have done this, your Mercedes-Benz battery should be exposed for you to work on.

Remove Battery Terminal

You are going to need to have a 10 MM socket wrench in order to proceed with this Mercedes-Benz repair. You were going to use this to remove the positive and negative battery terminals as well as the battery bracket.

Be careful when doing this, and make sure you do not damage anything surrounding the battery or the battery bracket. Fully remove the battery and set it aside to discard later.

Install New Battery

Once you have removed the Mercedes-Benz battery, you can take your replacement battery and install it in that same location. Carefully screwing in the battery brackets to secure it underneath the cabin air filter housing.

Connect the negative and positive battery terminals and replace the cabin air filter housing over the top of the battery as it was before. Making sure that everything is secure and screwed and just like it was for security.

This is a very simple repair that anyone should be able to do, even if you have very limited auto experience. Most people say that it only takes them 20 minutes at the most and the hardest part is simply locating the battery itself.

So this is most likely a repair that you could handle on your own without the added expense of hiring someone to do it for you.

Driving With an Auxiliary Battery Malfunction

If your Mercedes-Benz C 300 has an auxiliary battery malfunction, you may be wondering if you can still drive it safely. The good news is that this malfunction does not directly affect how your vehicle runs.

You will still be able to start and stop your vehicle like normal and use all of the basic functions necessary. This mainly targets the electronic features of your vehicle, such as the radio, Lane assistance, GPS, etc.

The bad thing is that this can be a distraction to you, when you are driving, especially if these are features that you use. You will not be able to rely on these features until the malfunction is fixed as they will be displaying incorrect information and errors.

The radio and temperature settings may automatically turn on or off, while other features may go off while you are driving as well. Creating quite a serious distraction depending on how long you put off this repair.