When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi everybody. I don't know if someone has mentioned this problem before, I am new here and new MB w213 owner. I 've read some posts about it and I am little confused. Is the voltage converter that has problem or the second smallest backup battery? For the record is there a second battery in my model or is only a voltage converter?The eco mode working fine, the start stop the same, the hold working also fine. I don't know what is it. Maybe if I put it on the diagnostic computer can i erase this fel?At the beginning it was red warning, flashing 2 times then and know on white all the time and it doesn't go. I have the w213 e class 2016- 2017 model 220d automatic. Any suggestions what is it?
Hi everybody. I don't know if someone has mentioned this problem before, I am new here and new MB w213 owner. I 've read some posts about it and I am little confused. Is the voltage converter that has problem or the second smallest backup battery? For the record is there a second battery in my model or is only a voltage converter?The eco mode working fine, the start stop the same, the hold working also fine. I don't know what is it. Maybe if I put it on the diagnostic computer can i erase this fel?At the beginning it was red warning, flashing 2 times then and know on white all the time and it doesn't go. I have the w213 e class 2016- 2017 model 220d automatic. Any suggestions what is it?
I think you're confusing your model with the hybrids, which have a 48V system with voltage converter. A pure diesel just has a 12V system. The second (auxilliary) battery is a smaller 12V battery that is supposed to maintain a nominal 12V for all the fancy electronics in case the main battery goes low. The most likely fix for your warning is to replace the aux battery.
I think you're confusing your model with the hybrids, which have a 48V system with voltage converter. A pure diesel just has a 12V system. The second (auxilliary) battery is a smaller 12V battery that is supposed to maintain a nominal 12V for all the fancy electronics in case the main battery goes low. The most likely fix for your warning is to replace the aux battery.
Thanks whoover. I was comfused because when i search for this auxiliary battery for w213 all the time pops up this voltage converter. Now i know tis not för diesel but for hybrids. This battery is front in the engine area or in the trunk under the carpets?if you know it will help me to find it quicker. Thanks again!!!
Thanks whoover. I was comfused because when i search for this auxiliary battery for w213 all the time pops up this voltage converter. Now i know tis not för diesel but for hybrids. This battery is front in the engine area or in the trunk under the carpets?if you know it will help me to find it quicker. Thanks again!!!
I'm not sure because I don't think we see this model in the US. There are some youtubes that might help. You're looking for a small battery, like a motorcycle battery.
My guess is: it's used to be called aux battery in older models, now it's slightly different and it's called voltage converter.
That explains why searching for the aux battery for w213 yields the voltage converter results.
Had the aux battery malfunction message on and off for about a month, then went ahead and order a voltage converter for about $100. However that message was gone during the few days while waiting for the part.
I'm obviously holding for the part for now, in case the message appeared again.
As for replacing it, there is a thread on the w205 forum (which shares the same tech I guess) where people explains the whole thing
Look for posts #10 and #19
In 19, the last image shows the part under the number 210
My guess is: it's used to be called aux battery in older models, now it's slightly different and it's called voltage converter.
That explains why searching for the aux battery for w213 yields the voltage converter results.
Had the aux battery malfunction message on and off for about a month, then went ahead and order a voltage converter for about $100. However that message was gone during the few days while waiting for the part.
I'm obviously holding for the part for now, in case the message appeared again.
As for replacing it, there is a thread on the w205 forum (which shares the same tech I guess) where people explains the whole thing
Look for posts #10 and #19
In 19, the last image shows the part under the number 210
I searched the trunk area and i found nothing. I guess you are right. I will search under passengers carpet where I think the converter will be. Thanks all of you for the advise. As soon as I have results i will inform the forum for future solutions of this problem on the w213 models. 👍👍
It would be interesting to know where that small Aux battery is located in the 213? In my S class the battery only lasted about 2 years. It was in a tough spot to access. From the info above if it's like the C class looks like it might be inside the passenger compartment up near the drivers footwell near the obd port?
This thread peaked my curiosity, and google led me to this site with parts diagrams. This page seems to show the voltage converter is somewhere in the front passenger area of the car. In browsing through the other pages, there was no reference to any other battery other than the main battery on page 6. Hope this helps. Good luck!
This thread peaked my curiosity, and google led me to this site with parts diagrams. This page seems to show the voltage converter is somewhere in the front passenger area of the car. In browsing through the other pages, there was no reference to any other battery other than the main battery on page 6. Hope this helps. Good luck!
Yes, the terminology is a bit confusing. Some models (maybe all W213s?) have a "voltage converter" in lieu of a second battery. This is really a small bank of capacitors with a charging circuit. Capacitors store charge and so are equivalent to lead-acid batteries in that sense. They can't store as much charge, but theoretically don't require maintenance and have longer life. For instance, I often replace the coin battery in a PC (whose job is to keep the ROM charged when the PC is off) with a capacitor.
But apparently the caps in this pseudo-battery are not up to the task and fail. It also looks like it's a bit of a job to get to.
Hi everyone. This week I made some calls in Greece to recommended MB mechanics. Auxiliary battery malfunction message depends to the model they said to me. Some w213 models have second battery and some not. You have to see it accordingly to identity registration factory number of the car. Mine is in the ending of 2016 and IT DOESNT HAVE SECOND BATTERY. They said to me that under the passengers foot carpet there is a voltage converter and it is for the gear box function, not the eco start stop or something else. Ok, now am thinking, if it isn't a battery it must be in the new car guarantee I have. So I went to Mercedes dealer again and this time was a guy, not a woman employee. I said my problem, he looked at it and he said I was correct, it was in the new car guarantee and they will replace it. The first time I went it was a woman and she said to me that batteries are not included in the new car guarantee. So, if someone else has this message " Auxiliary battery malfunction " depends on the model if it is battery or a voltage converter guys.
Good find. Ya, whenever I get a woman on the phone in any service dept I'll generally call back again and try to get a man on the phone. Most woman don't know what they are talking about with cars. I saw that many times over the years. We had a couple women when I was in tech school and they changed their majors. Over the years at my car service place I hired just one woman to work behind the counter and she use to drive my customers nuts with misinformation. One morning I had to come in late and there was a ambulance in front of the building and they were carrying one of my best customers out on stretcher, she gave the poor guy a heart attack with all her mis information, true story. From then on I always stayed behind the counter to point where I got so burned out I had to get out of the business. I sure hope my car does not have the Aux battery as those don't last long I've found.
Ok bringing back this old thread. I still have not found the answer to my question. I have a 2019 E450 Wagon in the USA. Does this car use the small motorcycle battery hidden somewhere in one of the compartments or does it use the capacitor circuit part (also called a voltage regulator) like in the C class benz. I'm just wondering as my E450 Wagon is in long term storage and I'm hoping I don't come back to a shot Aux battery from not being on a maintainer, I do have the main battery under the hood on a maintainer. Hopefully my car uses the capacitor circuit vs the small motorcycle type of battery. My experience with my S class cars is those only seem to last 2 or 3 years.
One 12V/80AH battery in engine compartment, and voltage converter (part # 2059053414) driver side interior foot well. If want confirmation post or PM VIN.
One 12V/80AH battery in engine compartment, and voltage converter (part # 2059053414) driver side interior foot well. If want confirmation post or PM VIN.
Thanks appreciate it. It's a relief my 213 does not have the motorcycle small type aux battery as the car sits a lot and that probably would not last long. The main battery is left on a battery maintainer.
One 12V/80AH battery in engine compartment, and voltage converter (part # 2059053414) driver side interior foot well. If want confirmation post or PM VIN.
Very informative post. Do you know if the standby function, that can be activated for about 26 weeks maximum, draws current from the lead acid battery, or this capacitor (aka voltage converter).
The latter naming convention is really confusing, since for hundreds of years - its been that long ! - batteries were devices created using electrochemical reactions, lead acid, NiMH, Li Ion etc. A capacitor also stores electrical energy, but the underlying principles are fundamentally different. MB has caused huge confusion by using battery for both components in the vehicle warning information
Very informative post. Do you know if the standby function, that can be activated for about 26 weeks maximum, draws current from the lead acid battery, or this capacitor (aka voltage converter).
The latter naming convention is really confusing, since for hundreds of years - its been that long ! - batteries were devices created using electrochemical reactions, lead acid, NiMH, Li Ion etc. A capacitor also stores electrical energy, but the underlying principles are fundamentally different. MB has caused huge confusion by using battery for both components in the vehicle warning information
If you mean the standby mode that is suggested for when the car will not be driven for an extended period, all it does is shut down the cell communication with the mother ship that monitors the car's status, allows remote start, etc. It doesn't draw current from anything; it turns off some current consumers.
As to the naming, from an engineering perspective a capacitor is not a battery. But from a user's point of view, the car had two batteries, a starter battery and an auxiliary battery for most other functions. Changing the energy storage technology doesn't affect how a non-technical owner will visualize it. When the little lithium battery on the motherboard dies in any computer I own, I replace it with a supercap. It would be pedantic to make the point that the BIOS settings are no longer maintained by a battery. A techie friend might find it interesting, but nobody else would.
I know this is an old thread but just in case it is any use to somebody else, here’s how I got on. Got the “auxiliary battery malfunction” message on my w213 2016 model E220d. Ordered and replaced the “voltage converter” which is under the passenger footwell behind the kick board. That did not fix the fault. Eventually I found that a fuse was blown in the main fuse box in the engine compartment. It was a 10A (labelled 10S for slow acting) and it was in fuse position 121, according to the fuse diagram, but its function is not listed on the fuse chart. That fixed it.
Thanks, that is the one :-) My fuse chart supplied with the car is much less detailed than that. And 121 is the park pawl capacitor a.k.a. voltage converter.
04-30-2019, 01:49 PM
