Hi @Bkteeria it might the auxiliary battery. It's really hard to work out which Mercedes cars had auxiliary batteries and which didn't and when they stopped fitting them etc. I have heard that the smaller auxiliary battery can cause this fault. Just for info, the auxiliary battery keeps everything running in your car when the engine stops when you are using stop / start BUT the auxiliary battery only charges if the main battery is already fully charged. They suffer the same fate as your main battery in that they tend to give up after 5-6yrs. Please do some extra reading about it on forums because I'm not 100% sure this is your issue, it's just something I have read about but never actually experienced on my car. Here is a video about where it is located, what you could do is access and charge the auxiliary battery (if your car has one!). If that temporarily cures your problem and then it comes back again, then you might decide to replace it. kzfaq.info/get/bejne/r5tddZpnl5qzpHk.html Hope that helps! Thanks, Phil

Might be the battery isn’t a agm gel or right requirement

Yes, there are a few things that can cause it, that are battery related. Some cars actually had a small auxiliary battery (about a 1/4 the size of the main battery) and when it fails, it causes this problem. As you Merc, then moved to a capacitor system. I think it is worth checking out and if the main battery is ok, it could very well be your problem. Cheers, Phil

@kenperrin8582 Never say never but I have "never" 😂 lost radio memory or stations when swapping a battery on a Merc. I have changed them on our 2007 CLK and our two 2018 Mercedes cars. So, I would say you are good to go. I wouldn't leave the battery off for hours though, just one out and one back in again straight away. If you are really concerned, there is a method using a set of jump leads where you can swap batteries without ever disconnecting the battery. This info you need is at 21min 43secs in this video: kzfaq.info/get/bejne/j6ldYLB9s6_GmZ8.html Hope that helps! Thanks, Phil

@skandiflick Thanks! 👍😀

The only thing that I can think of is that some cars have an auxiliary battery. It helps power the car during stop/start. These also get past their best and cause this warning message. Google: “Mercedes auxiliary battery forum” and you will get lots of hits. Be aware your car may not have an auxiliary battery but it is worth checking! Cheers, Phil

It’s because Mercedes said this week because I have one as well. It’s because it doesn’t have that significant voltage that the car needs basically so you can take it to a shop and they said it’s gonna be good which it is good but it’s not Mercedes standard Good basicallyyour car is not good enough to keep

Hi, the capacitor or auxiliary battery can also be the cause. I imagine disabling the start / stop can also cause it depending on how it has been done. The Merc ECU monitors quite a few things to decide if the car is ok to start stop and so if something was disconnected, it may be telling the system there is a problem with the battery power available, which brings up this error. If it’s possible to reach out to the previous owner I would ask them how it has been done. If it has been mapped out, they may have missed something. Hope that helps! Cheers, Phil

@@ReviveMyRide thank you for the reply. I think I'll bring it to the dealer for a checkup and get it diagnosed. My mechanic didn't find anything strange with Launch diag. Unfortunately the previous owner doesn't know start/stop situation either. :D

@@DARKredDOLLARok makes sense, hope you get it sorted and if you have time, would love to hear back what resolved it for you. Cheers, Phil

The shop where they installed it said because “ it’s a Mercedes and has all these extra modules… new cars “

Can I just ask, it sounds like your interlock device became intermittent before it (possibly) failed, hence you started to blow into the port. Were the symptoms exactly the same? Dash lighting up and all that stuff? If so, good chance it is the device. I had this once with my TVR, had to take some of the dash out to get to the “box of tricks” that enabled the starter and bypass it with a standard connector block. Hope that helps! Cheers, Phil

Happens sometimes, glad it went away and hope it stays that way for you! 👍

I've read that some people find they need to program in a new battery but I don't understand it because I've never had a problem. I've Recently put two new batteries onto 2018 Mercedes cars with no issues. I have a 2006 and a 2015 BMW, regularly disconnect the batteries swap them over if I need to with no issues. Hope that helps! Cheers, Phil

Hi, when you fit a new fully charged battery, it should cure this fault, not introduce it. just to explain the fault code: It is triggered when the battery is low. So, if you have an old battery that isn't holding very much charge anymore or if you have been using your car battery with the engine switched off (lights / radio etc), then the error message will tell you to start the engine. Basically, what it is asking you to do is to charge the battery. When the engine is running, the alternator will charge up the battery. If this error comes on after a new battery is fitted, I would guess that the new battery wasn't fully charged when fitted or it isn't any good (been sat around too long). However, if you do long journeys (say about 1hr of constant driving), then it should have charged up by now on it's own. If you have a trickle charger, you can charge the battery overnight. If this keeps happening or the fault doesn't go away, then I would return the new battery and get another. Hope that helps!

Did you solve it? I have the same problem after changing the battery

Hi @Pufferkusser I remember your username from before, welcome back and thanks for being a regular viewer! 🙌 Also for the great questions! Here we go... It's amazing how often Mercedes won't cover something that is essential to the car. Arguably batteries are "consumables" but even when they fail much earlier than expected? Shame on them! JUMP TERMINALS: These do work but in my opinion, direct to the battery is always better, less connections and components in the way. Also, I knew I was going to be replacing the battery, so I was taking the trim off anyway 😉 AGM CHARGER: I've done a quite a bit of reading on this. Again, just my opinion but "AGM charger" is a marketing ploy, what you really need is a battery charger that meets the needs of an AGM battery (whether they say AGM charger on them or not). I have the Maypole charger that you saw that charges low (5A) and slow, which AGM batteries like. I also have a trickle charger for maintaining the battery, in general these won't bother an AGM battery either. Of course, if you are in the market for a new charger, why not buy one that says AGM on it just to be sure... CODING: Never come across a Mercedes battery yet that requires coding. Also, with some cars, you have to be careful to maintain the battery supply to the car during the battery swap. Never had a problem with Mercedes with this yet either. But, I have two 2018 cars and I have swapped batteries on both with no issues. So, if new cars have additional requirements, I may not be aware yet. Sorry for the long message! Hope it helps, Thanks, Phil

My glc battery needs to be coded of sorts... The car needs to be told its a new battery

Hi, really sorry, I haven’t heard of or carried out a transmission reset before. Can I ask, is your car a 7 speed auto or a 5 speed? The reason I ask is that the 5 speed has an electrical connection that goes into the transmission that needs to be changed during servicing. If it hadn’t been, it can cause the problems that you described. The 7 speed doesn’t have the same electrical plug / connection. Thanks, Phil

@@ReviveMyRide Good evening Phil, thanks for your reply,my car is 6 speed gearbox, regarding the transmission reset, i looked on youtube and you have to put your foot all the way down for 30 secs, with ignition on, then leave for 5 mins, that apparently resets the transmission, and should be done once a month, thanks again charlie

@@charlesalderson9738 Wow, that reset information is interesting! and I take it, it cured your problem? thanks for sharing! Cheers, Phil

@@ReviveMyRide Hi Phil thanks again for replying, i meant to write on my last email, put your foot hard down on the throttle, then leave for 5 mins, without opening door, then drive normally for a while, I know absolutely nothing about cars, but it seems to have worked, regards Charlie

No probs at all! Hope the vid helped you fix your problem 👍😎 Cheers, Phil

@ReviveMyRide Thank you. I have been working a half mile away for months now, and took it out for a good run,after watching your video. But wouldn't have known that but for you. Servicing video very helpful too. Kudos to you Sir.

Sorry, wish I knew the answer! Mercedes gremlins? 🤷‍♂️ The only thing I can think of is that for a few years, some cars had a small auxiliary battery located in the boot (or side panels in the boot). If this battery gets old, it can cause a similar problem. Thanks, Phil

Same problem here. Changed both batteries brand new and this warning still every morning

I was told by a breakdown recovery guy that sometimes (depending on the speed you are trying to charge at) you can blow a little regulator that is part of the system when using the charging ports. Unconfirmed but it was enough for me to be cautious if I'm not in a rush. I'm sure a trickle charger would be fine on the charger points though 👍 Thanks, Phil

Yep, as you say, if you have a car that isn’t used very often, sometimes the problem is just that the battery is low and a good run will put some charge into the battery and the error message goes away 👍

I think you mean that you have the "Check engine light" warning but the car seems to be working fine? If so, it may seem like it is working ok but it isn't it will probable be running a "safe mode" Best to read the fault code as shown in the video and see what it is telling you, there are a lot of causes for a check engine light.... Hope that helps, Thanks, Phil

@@ReviveMyRide no i got the popup. Start engine see manual (and a picture of the battery). For 3/4 days after i didnt drive for a few days. Now its gone. I didnt notice 1 slight issue. Have a servicing soon. Lets see.

Hi @arnietwo Thought you might pick up on that! 😂 I’m happy to service it but it’s my wife’s car now and she always likes to keep full MB service history on her Mercs, I just get to do the dirty jobs like brakes, suspension etc… 😞

@@ReviveMyRide eh no, u can do it better and cheaper !

This I am 100% sure that you need to Replace the starter My C3 had the same issue. It was shut off while moving and normally it happens when the ego stop start gets engaged Unfortunately, the eco-stop start ends up wearing the starter very quickly, so my suggestion is before hopping in the car turn off eco-stop and never ever ever use it

Sorry to hear about the issue you are having with your car. That is a very strange fault and not one I have had to tackle before. Hope you manage to get to the bottom of it!

It’s probably the alternator