12V BATTERY ISSUES WITH GLC 4MATIC AMG LINE COUPE 2022

[mattkh]

They informed me that the problem is the auxiliary coolant pump is running on after the vehicle is turned off

The aux coolant pump should run after ignition turned off, BUT should stop after say 5 mins.

 

[Rippedoff]

The aux coolant pump should run after ignition turned off, BUT should stop after say 5 mins.

Yes I understand that but it continues enough to drain the battery

 

[cataloyking]

as earlier i have had a new battery fitted the software has been updated and still have the same problem it makes you sick after spending all that cash on supposedly a quality motor

 

[cataloyking]

Well my Saga continues, picked the car up on Friday, new battery installed, but only partially charged, I asked about this and they stated that it would charge whilst driving. Saturday evening there was a Mercedes Me email telling me that my 12v battery was critical and the dashboard stated the same.

Had a busy weekend so really not been anywhere but tomorrow, I am doing a 2.5 hours round trip so here's hoping, failing that I am going to have the alternator checked.

Any other suggestions? bearing in mind I am not a man and my knowledge is very limited.

i have the same problem a new battery was fitted and software updated 2 days later still the same warning light on never a problem starting the car the warning light goes out when started but comes on again next day my car has been in the dealership more often than been on the road always say its fixed when returned they dont seem to know whats wrong

 

[cataloyking]

is this still the yellow sign saying 12v battery see owners handbook thats coming up if so mine has been doing this since 6months old been in and out of mercedes lots of times after a lot of calls to mercedes in the netherlands they are writing a new programme for a component which will be sent to mercedes outlets shortly and they will instal it into the cars that are affected mainly glc models hope that helps you

 

[cataloyking]

Hi,

I have read many posts regarding the issues with the Mercedes 12V battery, my car is less than 12 months old, I even brought my service forward to try and get the issue resolved. In the first 8 months I didn't have any issues with my car. But I started to get emails and the 12v battery was showing critical on the Mercedes Me App. I know a lot of people don't like the app, but I find it a good indicator and more often than not when I get in the car after the notification on the app there is a warning on the dash.

My car has been in the dealership every week for the past 3 weeks, today was the last straw I got it out of the dealership with a fully charged battery, but when I got home 3 miles later within a couple of hours I received an email stating that the 12V battery was critical, surely this cant be right.

I am convinced there is something wrong with the battery but the dealership cant find anything wrong with the diagnostic's, I know I don't drive it longs runs every day, but at weekends it is driven on the motorway for hours. In fact I am taking it out on long runs when I don't need to go anywhere, using petrol that I don't really need to use, to try and resolve the issue, I fear that one day it wont start.

Is any one else having the same issues and how are you getting on having the issue resolved.

Many thanks in advance.

i have had the same problem since new been in and out of dealership always say its repaired but never happened i got in touch with merc in the netherlands and after a few calls a manager spoke with me and they have found the problem it is a component that needs a new programme written and is in hand they are going to send it to the dealership and they will instal it mainly glc models that have this issue fingers crossed

 

[tllowry]

Hi,

Now found out what is wrong with the car and others are bound to have the same issue, after going on holiday and leaving the car with the Dealership and telling them, until they can find the fault, I wont be collecting the car and they could stick it up their a@@@.

They informed me that the problem is the auxiliary coolant pump is running on after the vehicle is turned off and locked. At present there isn't a permanent solution and Mercedes are working on a fix. The temporary solution is approximately 20 minutes after the vehicle has been locked, the vehicle should be unlocked and locked without opening any doors, this interrupts the pump stopping it from discharging, this can be done via the key or with the app (not very security savvy).

Complete and utter joke, yes I have the car back and yes if I do the above it stops the battery being drained but not what is expected on a 57k car.

If anyone else is having this problem get on to your dealership they now know it is a problem but are failing to tell customers.

I bought my 2023 amg glc43 last December and have been having the same problem since I bought the car. I have provided the dealer with your comment and hoping this solves my issue as well. It got so bad I contacted Mercedes and they are reviewing as a possible lemon/buyback but I really hope they come up with a fix for this but unfortunately so far they aren't believing what they can't prove. Fingers crossed!

 

[Rippedoff]

I bought my 2023 amg glc43 last December and have been having the same problem since I bought the car. I have provided the dealer with your comment and hoping this solves my issue as well. It got so bad I contacted Mercedes and they are reviewing as a possible lemon/buyback but I really hope they come up with a fix for this but unfortunately so far they aren't believing what they can't prove. Fingers crossed!

Hi,

Did you get your issue resolved I have been informed that it will be October before Mercedes write a new programme,

Although the fix that they have told me to do works, it is far from ideal.

Regards

Keri

 

[SL63 Mark]

I am wondering what function the auxiliary coolant pump serves, presumably it continues to circulate engine coolant after engine shutdown, to facilitate hot starting or cabin heating ? I would be thinking about disconnecting it as a temporary fix while this problem is sorted. This kind of functionality may be useful in Arizona where temperates reach 50°C, or Antarctica where they reach 40° below, but is essentially pointless in the UK.

Mercedes sometimes fit devices to their cars which overcomplicate and serve no purpose.

 

[mattkh]

Mercedes sometimes fit devices to their cars which overcomplicate and serve no purpose.

Also used by other manufacturers.
Controlled cooling is beneficial to. metals.

 

[malcolm E53 AMG]

Engine ancillaries shouldn’t be run from the main battery on cars nowadays there is such a high current draw on the 12V battery system starting the engine, COMAND and air con etc, adding an electric cooling pump is just asking for trouble - I thought they were only using electric cooing pumps with the 48V hybrids, obviously not

 

[Carlos.amg]

I have the same issue, new battery supplied and fitted, software updated still get the warning on the app and in the car, it’s no better than before the battery replacement. It has been on the diagnostic system with nothing remarkable to report apparently. I was told I wasn’t driving it enough? Never had this issue with my E-class and my usage is the same!
i just can’t seem to find anyone with experience of diagnosing this issue and effectively repairing it, many just say they haven’t heard of the issue!

 

[Carlos.amg]

Does anyone know how far back the issue goes with the auxiliary coolant pump? My GLC350 is a 2018 car and has the battery issues described here, is it plausible this age vehicle has that issue?

 

[Carlos.amg]

The cars future hangs by a thread, seems the ongoing battery drain issue has sent a battery just on two years old to the great battery park in the sky! So at around £450 for a new battery and with the issues surrounding the discharging of said battery it appears Groundhog Day is upon me again. Mercedes state the auxiliary pump issue is only connected to those vehicles with a 48 volt battery? Has anyone got the problem on a vehicle that doesn’t have the 48 volt battery? I am not prepared to fire the parts cannon at this thing after Mercedes have said there is nothing wrong in the diagnostics of the car!

 

[Carlos.amg]

Can anyone recommend a service provider in the U.K. that can get to the bottom of the battery drain issue? I simply don’t trust the dealerships to relieve of anything but my money!

 

[malcolm E53 AMG]

I’d seek out an auto electrician to find out where the current draw is going there are various how to videos on YouTube if you fancy DIY

 

[Headhurts]

I watched a video on YouTube I believe where someone had a problem with their GLC battery constantly going flat, the car had keyless ignition and the keys where stored quite near the car so we’re constantly communicating with the car causing the car battery to go flat.

Robin

 

[Srdl]

Can anyone recommend a service provider in the U.K. that can get to the bottom of the battery drain issue? I simply don’t trust the dealerships to relieve of anything but my money!

A location on your profile would help

 

[Carlos.amg]

I watched a video on YouTube I believe where someone had a problem with their GLC battery constantly going flat, the car had keyless ignition and the keys where stored quite near the car so we’re constantly communicating with the car causing the car battery to go flat.

Robin

Thank you, I had seen something similar, I keep my keys in RFI pouches to prevent the associated potential issues with keyless entry and starting.

 

[Carlos.amg]

A location on your profile would help

Good point, well delivered. Amended as suggested, thank you.