Auxiliary Battery Malfunction Mercedes E350

Share This Post

Can You Drive An E350 With An Auxiliary Battery Malfunction

Mercedes E350 W212 auxiliary battery location and malfunction DIY fix! Step by step replacement!

Yes, its possible to drive an E 350 with an auxiliary battery malfunction. The auxiliary battery does not affect the ability of the vehicle to start. It is only used for emergency and ECO functions.

If the voltage of the auxiliary battery is below the specified range then the ECO start-stop will not work. In the pre-facelift model, the vehicle will not be able to engage the P gear when the main battery discharges.

The cost to fix the auxiliary battery malfunction depends on the type of battery and the generation of the E 350. On average, it can cost between 200-300 USD but if the auxiliary battery is not replaced soon then it can damage the main battery of the vehicle.

The battery management system control unit is always monitoring the voltage of the main battery and auxiliary battery. It connects the auxiliary battery to the main battery in order to charge it.

If the new auxiliary battery malfunctions again then the auxiliary battery relay may be the cause since the relay is used to connect the main battery to the auxiliary battery.

How Much Will A New Auxiliary Battery For My Mercedes

A Mercedes-Benz auxiliary battery replacement typically costs between $200 and $300. Labor expenses are predicted to range from $50 to $100 these estimates are subject to change.

You might want to take your car to a Mercedes repair facility or replace the entire auxiliary battery if this does not solve the issue. If it has lost charge, it might malfunction frequently much like the main battery.

Are There Any Other Potential Issues That Could Occur As A Result Of The Auxiliary Battery Malfunctioning On Your Mercedes

If the auxiliary battery in your Mercedes-Benz vehicle develops a fault, there are a few different problems that might manifest themselves.

To begin, there’s a chance the engine won’t start. This is because the starter motor may be powered by the auxiliary battery, and in the absence of the auxiliary battery, the engine will not turn over.

In addition, there is a possibility that the power steering and brakes will not operate correctly if the auxiliary battery is not working properly. This is because both of these systems require the presence of electric power to function correctly, and if the auxiliary battery is not present, there is a possibility that they will not have sufficient power to function correctly.

If the auxiliary battery in your vehicle is not functioning properly, none of the lights may turn on. This includes both the front and rear lights, as well as the lights inside the vehicle.

Therefore, even though a faulty auxiliary battery might not directly pose a threat to someone’s safety, it could certainly lead to some inconvenient and potentially dangerous situations if it continues to malfunction.

Don’t Miss: Where To Get Battery Replaced Car

Where Is The Mercedes Auxiliary Battery Located

Mercedes-Benz puts the auxiliary battery in multiple locations, depending on which model you drive. If you are looking to replace the secondary battery yourself, you need to know where to look.

The common locations where to find the auxiliary battery on a Mercedes include:

  • In front of the windshield in the engine bay
  • Underneath the front passenger seat
  • Inside the dashboard on the drivers side
  • Within the engine bay
  • Behind the drivers seat

If you arent able to find the auxiliary battery in your Mercedes, you can find the location in your service manual. There are also diagrams available online if you need more support.

Voltage Converter Part Numbers And Compatibility

2014 mercedes e350 auxiliary battery malfunction. Would this explain ...

Mercedes-Benz part has few different OE numbers, which are below, additionally for our blog readers we have collected a list of compatible cars as well.

Auxiliary battery voltage convert has 3 part number, the newest one is A2059053414, which supersedes older numbers A2054400073 and A2059052809.

The most common Mercedes-Benz warning messages for faulty A2059053414 auxiliary battery:

  • Auxiliary Battery Malfunction
  • Bateria auxiliar falha

The most popular diagnostic trouble code DTC for faulty converter:

  • B21DC01 – The buffer battery of the electronic ignition lock has a malfunction. There is a general electrical fault
  • B21DC01 The buffer battery of the electronic ignition switch is faulty. A general electrical fault exists

Hella Voltage Stabilizer oem number:

Mercedes-Benz voltage converter part numbers:

  • A205 905 34 14 80

Voltage converter part number A2059053414 supersedes:

  • C Cass W205 Saloon Sedan
  • C Class S205 Estate Touring
  • C Class A205 Cabriolet Convertible
  • C Class C205 Coupe
  • C Class 2014 2015 2016 2017 2018
  • C Class C180 C200 C220 BlueTec C250 C300 C350 c350e Hybrid C400 C450 C43 C450 C63 AMG
  • CLC W257 2017 2018 2019
  • E ClasS W213 Sedan
  • E Class 2016 2017 2018 2019
  • E Class W212 S212 A207 C207
  • E Class E200 E250 E300 E350e Hybrid E400 E450 E200d E220d E300d E350d E400d 4MATIC E43 E63 AMG BlueTEC
  • ML-class W164 ML250 ML300 ML350

Read Also: Change Battery On Honeywell Thermostat

How To Replace Auxiliary Battery On Mercedes Benz

For some owners of Mercedes it might an issue and big question mark, meanwhile experts in DIY might replace it without any hassle.

We always recommend to use professional garage or fitter to do that job, but if you have decided to save money and do it yourself you can always follow our guide, which includes step by step explanation how to replace auxiliary batter. Once replaced there is no need to visit dealer shop it will fix auxiliary battery malfunction instantly.

This guide could be found here:

Is It Safe To Operate A Vehicle While An Auxiliary Battery Malfunctions

The answer is both yes and no. It is never a good idea to operate a vehicle that has any type of issue since you never know how it may impact other operations or performance.

Image Source:

According to our knowledge and experience, when a new generation voltage converter, also known as an auxiliary battery, fails, it is safe to drive for at least 100 miles and possibly even more. This means that this component is primarily in charge of extra accessory functions like “stop/start” and other accessories that aren’t crucial while you’re driving, so you can continue to operate your Mercedes.

Recommended Reading: Replace Battery Hyundai Key Fob

What To Do Next

In many new Mercedes models, the auxiliary battery is located at the top of the front passenger footwell. You will need to remove some nearby plastic mouldings and peel back the carpet to gain access to the battery area, and the fastenings can be undone with a 10mm socket. You should also disconnect the main battery before attempting the work.

Once the fastenings and the plastic cover are removed, you can take out the voltage converter by taking off a couple of small tabs. The voltage converter is also known as the capacitor, and can be easily sourced. It is a relatively common problem for the current Mercedes C-Class S-Class , E-Class and GLC-Class , amongst other models and A205905341480 capacitor prices vary online.

Then, simply reverse the process of removing it. You will need to re-fasten the two clips and leads that hold the voltage converter in and bolt the square plastic cover back on. Make sure the carpet is fitted as it should be when you reattach any plastic trim pieces you have taken off.

If your car for example is S-class W221 R-class R251 ML W164 GL X164 etc different than listed above, it’s battery location will be different and it should be in the trunk area near fuse box.

For E-class W212 S212 C207 A207 A0009829308 auxiliary battery is located at the driver side on the side panel upper one, to access it you will need to remove plastic protection cover.

Auxiliary Battery Malfunction Mercedes

Auxiliary Battery Malfunction: Mercedes E Class W212 Replace

Auxiliary Battery Malfunction is a common error message when the Mercedes-Benz auxiliary battery fails. Mercedes-Benz uses an aux battery to operate the transmission and critical accessories in critical situations.

The most common issue that triggers this error on Mercedes-Benz vehicles is a dead auxiliary battery .

In most cases, to fix Mercedes-Benzs auxiliary battery malfunctions, you must replace the auxiliary battery. This repair takes about thirty minutes.

The auxiliary battery location varies between models.

The auxiliary battery is typically located in one of these locations:

  • the left side of the dashboard
  • in the engine bay
  • under the front passenger seat.

In some models, the auxiliary battery may be in the engine bay , under the passenger seat , trunk, and behind the drivers seat we will go into more detail later.

This guide will explain everything you need to know about the auxiliary and replace it yourself for under $100.

Newer Mercedes-Benz cars and SUVs have two batteries:

  • Main battery System battery, starter battery, or G1. Its primary function is to start the engine and be the primary power source for all electrical systems.
  • Auxiliary battery . Also known as the secondary battery, backup battery, aux battery, or G1/7. Usually an AGM battery. Typically specs: 12V, 1.2Ah, 170 A. Supplies power if the main battery voltage is low. Part number: 000000004039

You May Like: Where Can I Recycle Car Batteries

How Important Is This Service

While a failed auxiliary battery will not prevent your vehicle from driving, it can cause significant complications, including important accessories malfunctioning or not working at all. It can also put additional strain on the rest of your charging system components. Have the auxiliary battery replaced as soon as possible.

Fast and easy service at your home or office

Backed by 12-month, 12.000-mile guarantee

Mercedes E350 Auxiliary Battery Malfunction Would This

2014 mercedes e350 auxiliary malfunction. Would this explain intermittent interruption of distronic an blind spot functions?

Mechanic’s Assistant: Have you tested the battery with a voltmeter? And can you see if it’s leaking or not?

Have not done that yet. I had planned to just replace at it is the original battery. Hoping replaement would resolve the othe r issues I mentioned

Mechanic’s Assistant: Are you fixing your E350 yourself? What have you tried so far?

Thought I could replace battery easily myself. Havent tries anything else as replacement seemed most logical what do you think. I have read that as battery looses power it gradually will shut down other sysytems it controls like distronics. Is that correct?

Mechanic’s Assistant: Is there anything else the Mechanic should know before I connect you? Rest assured that they’ll be able to help you.

Thats it

Hello and thank you for choosing JustAnswer.

My name is ***** ***** I ask yours?

also you may see a phone call offer come over, that is automated and just an option if you are interested.

also, in regards ***** ***** question about blind spot, no this battery generally does not affect that system.

The most common problem is corrosion in the sensors in the rear bumper.

Good morning Herb, how goes it sir?

yes, I would agree , different issues.

if you can send the vin of your car to me, I can tell you where the battery is located.

located behind the fuse box. see photo

Don’t Miss: 2012 Gmc Acadia Battery Location

What Causes Auxiliary Battery Malfunction Mercedes

If your Mercedes-Benz is equipped with an auxiliary battery, it is located in the trunk near the main battery. The auxiliary battery provides power to the electrical components when the engine is not running. If this battery malfunctions, it can cause a number of problems with your vehicle. One of the most common issues that can occur is the cars alarm system going off randomly. This can be extremely frustrating, especially if you are trying to sleep or concentrate on something else. In some cases, it may even prevent you from being able to start your car. Another problem that can arise from a malfunctioning auxiliary battery is that your cars interior lights may flicker or stay on when they should be off. This can be distracting and dangerous while you are driving at night. Additionally, it could lead to a dead battery if left unchecked. If you notice any of these issues occurring with your vehicle, it is important to take it to a qualified Mercedes-Benz technician as soon as possible. They will be able to diagnose the problem and determine whether or not the auxiliary battery needs to be replaced.

What Is The Purpose Of An Auxiliary Battery

Auxiliary battery malfunction mercedes

An auxiliary battery performs multiple tasks. In some vehicle systems, it can be utilized as a safety backup to support the main battery when needed to. However, most auxiliary batteries deliver voltage for particular accessories all the time.

Compare:Mercedes vs Audi

The auxiliary battery on the Mercedes-Benz models is used to run some electronics. So, if the auxiliary battery is missing from your car, you can still drive it but some accessories wont work. Besides, the function of the auxiliary battery varies from one Mercedes model to another.

In some models, the auxiliary battery is meant to operate the gear shift selector when the car dies. While in other models, this battery can run additional accessories, such as heated seats, sensors, stop/start functions, radio, COMAND, different radars, and much more.

Also Check: Best Solar Power Battery Bank

How To Tell Which Auxiliary Battery Is In Your E350

One of the easiest ways to check which type of auxiliary battery is in your E 350 is to check the vehicle identification number on the drivers side B- pillar. If the starting series is W213, it is the voltage converter.

The W212 has a conventional lead acid battery, if there is no ECO start stop button in the W 212 then it has the smaller 1.2 Ah battery in the dashboard also known as a buffer battery.

What Is An Auxiliary Battery In A Mercedes

Mercedes-Benz cars have two different type of auxiliary battery also known as mercedes secondary backup battery, it completely depends on the car model, year and many other specifications.

For example E class W211 S211 W212 S212 C207 A207 ML W166 GL X166 C class W204 S204 S class W220 W221 A clas W176 W177 CLA W117 CLS W218 C257 Sprinter W906 Vito W639 W447 B class W246 W247 G class W463 G500 G55 G63 AMG cars have small auxiliary battery located at the luggage compartment or under the front side upper cover at driver side and it is a copy of normal size battery just “mini” size and few models have this battery fitted under the driver side upper panel, connected the same way as main battery with positive and negative terminals.

So the first step is to check which battery is used in your mercedes by opening a hood and trunk , in the trunk this part is usually located nearby fuses if after inspecting these two places you weren’t able to locate small auxiliary battery it means your car uses voltage converter.

Auxiliary battery is responsible for running and powering additional accessories in the car such as stop go function and many other, once it detects failure none of these functions will work.

For other models for example C class W205 C200 C220 C250 C300 it has also auxiliary battery but it is more like small module ballast also known as voltage converter, but it has the same purpose as other type battery – to run and power up additional accessories on the car.

Recommended Reading: Change Battery In Honda Key Fob

How Much Does It Cost To Replace Mercedes Auxiliary Battery

The average cost for a Mercedes-Benz auxiliary battery replacement is between 200-300 USD. Labor costs are estimated between 50-100 USD, all of these prices are estimated and may vary. To save a lot of money xenons4u is offering auxiliary battery replacement part at our store and step by step guide to replace this battery, so labour charge will be saved as well.

If this does not completely fix the problem, you may wish to take your car to a Mercedes service center or replace the whole auxiliary battery. Like the main battery, it may fail repeatedly if it has lost charge.

What Causes The Mercedes Benz’s Auxilary Battery To Malfunction

auxiliary battery malfunction mercedes e class w212 replace ( E300.E350)

A warning message such as “auxiliary battery malfunction” or, in 2015 and subsequent models, a warning message such as “halt vehicle shift to P leave engine running” will appear when the auxiliary battery is unable to maintain a charge to recharge.

Both of these error messages are typical for Mercedes-Benz automobiles, and aside from the error message, the car typically functions and drives without issue.

If the vehicle starts and drives without issue, the auxiliary battery is to blame, but the dashboard keeps displaying the auxiliary battery malfunction error.

Mercedes-Benz has attempted to read the codes using a standard OBD-II scanner, but no fault codes have been shown. Since generic scanners cannot read Mercedes-Benz-specific fault codes, you will not be able to identify fault codes that suggest a faulty auxiliary battery using a generic scanner.

Image Source:

The secondary battery will be the cause of the problem if the car still starts and certain features operate. The mechanical operations of the automobile are unaffected by the supplementary battery.

Also Check: Battery Replacement Ford Key Fob

When The Auxiliary Battery Problem Warning Appears On Your Dashboard Computer What Should You Do

Whether or not the car is still safe to drive is the main question that individuals have when they see the DTC error code on their display.

These tasks include powering your entertainment system, and the PDC sensors, enabling the radars to operate properly and giving actions for the start/stop function. Auxiliary batteries are in charge of controlling extension functions in your car.

These parts and functions of your car will be significantly affected if your auxiliary battery malfunctions.

However, the overall mobility, as well as the drivability of the vehicle, are rarely impacted by these parts. Nevertheless, you shouldn’t put off fixing the issue for too long because doing so might result in later, more significant problems.

Like all other auto parts, auxiliary batteries deteriorate with use, therefore you will ultimately need to replace them.

Driving is not suggested if your auxiliary battery is giving you trouble. As long as you do not see a reduction in the general handling as well as the performance of your automobile, it is unlikely to place you through any immediate risk.

If it is only a malfunction, you might not even need to change your auxiliary battery instead, you would simply need to make the necessary changes to the onboard computer’s settings to enable it to interpret the battery signals correctly.

Related Posts

Signs Of Bad Car Battery

Starting Problems...