Fixing the “Auxiliary Battery Malfunction” Warning in a Mercedes

Mercedes-Benz is one of the best luxury automobiles with world-class performance! Some models are very advanced and have a special battery configuration for enhanced performance. 

 The Mercedes S550, for example, runs on dual batteries consisting of the main battery for starting the car, and the auxiliary battery which runs electrical functions. It’s not uncommon for the auxiliary battery to malfunction in some Mercedes models.

 This is always accompanied by an “auxiliary battery malfunction” warning on the dashboard. Seeing this for the first time can be scary, especially when driving.

 The good news is that you don’t need to stress over it!. This guide shows you how we fix the Mercedes auxiliary Malfunction. If you’re in the East Valley of Phoenix, we’ll be glad to help you solve this problem for good. 

 What Is the Auxiliary Battery?

The auxiliary battery is the secondary battery in some Mercedes models. It’s the main battery’s backup and is used to run the car’s electrical components like lights, audio systems, and air conditioners. In some models, the auxiliary battery is only a capacitor to store electricity.

 The auxiliary battery is charged by the inbuilt charging system like the main battery. It has a useful life of between four and six years, depending on how well you maintain it.

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 How Does a Faulty Auxiliary Battery Affect My Vehicle’s Performance?

An auxiliary battery malfunction affects your vehicle’s performance by causing errors in the car’s electrical systems. 

 If you have a faulty auxiliary battery, your car’s electrical components and safety features will stop working. This includes; Entertainment system, GPS, audio system, PDC sensors, Blind Spot Assist, and Lane Keeping Assist. The worst is that the car may fail to start or stop.

 What Type of Mercedes Auxiliary Battery Does My Vehicle Have?

Depending on your Mercedes make and model, there are three types of auxiliary batteries. Their location also varies depending on the car’s make and model. 

 So, how do you know which auxiliary battery type you have? Simple! Open your car’s trunk and hood. It would be best if you located an auxiliary battery alongside some fuses when you open the trunk. You should also see a small auxiliary battery underneath the hood.

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 What Will Happen if the Auxiliary Battery Malfunction Appears on the Dashboard?

The auxiliary battery experiences wear and tear like other car batteries. This causes the battery to malfunction. A warning message appears on the dashboard, alerting you to act fast.

 You should replace the auxiliary battery if your Mercedes starts normally, but the auxiliary battery malfunction message appears on the dashboard. Also, if this warning message appears on the dashboard, your car’s electrical components will fail since the auxiliary battery powers them.

 What Should You Do When You See the auxiliary Battery Malfunction Indicator on Your Dashboard Computer?

The auxiliary battery supplies power to your car’s entertainment system. This means you won’t have an entertainment system if the auxiliary battery is faulty. The battery also powers PDC sensors. So, the radar system will be affected when the auxiliary battery malfunctions.

 Last but not least, the auxiliary battery is a backup to the main battery. If the main battery fails, the auxiliary battery can start the car. It’s a pity if both batteries fail because you won’t be able to use the car.

 You don’t want to risk an auxiliary battery malfunction indicator on your dashboard. It’s best to act fast by having a certified Mercedes mechanic check it out and advise the way forward. The last thing you want is a Mercedes with stalled operations. 

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