C350e Battery Sign. E-Mode greyed out

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Merc1234merc

New Member
Joined
Jan 8, 2022
Messages
11
Location
London
Car
C350e
Hi. I’m new to this group and I hope someone can help me out please.

My c350e keeps showing the Red Battery sign + See Owners Manual.

It’s been consistently like that for the last 2 months now and I can’t use the Hybrid motor.

Last week, it started saying 12V battery critical on the MercedesMe App. Sometimes it wouldn’t start or go into drive or reverse.

I changed the big battery located in the boot (not hybrid battery). I thought this would solve all the problems but it didn’t. The red sign is still showing saying See Owners Manual.

Today, a mechanic plugged it into a machine and it came up with error code shown in the picture.

Can someone please help me out please because I’m lost for words and Mercedes Garage is fully booked for the next 2 months where I’m from.

I appreciate any help and I’m going to thank you in advance.

Thank you so much!
 

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How old is the car?
Where and when did you buy it?
What's the service history?
 
How old is the car?
Where and when did you buy it?
What's the service history?
It’s a 2016. Purchased it 5 months ago. It came with service history although now the service is overdue. Bought it from a private person with red battery sign on it. Previous owner was clueless as well apparently.

I plan on servicing it next month with a local garage as Mercedes quoted me £1300 for a full complete service.
 
If your in North or West London, talk to Terry at Wayne Gates is Harrow, he'll quote you a good price for the service and will get you booked in sooner than 2 months.

 
As for the error code, it's generic OBDII so it seems that the mechanic who scanned the car for fault codes is not a Mercedes specialist and does not have STAR diagnostic computer which is the Mercedes Benz tool.

STAR can scan all of the car's ECU and provide specific and detailed error codes (as opposed to the generic OBDII codes). It will also offer guided diagnostic that will allow the texh to pinpoint the failed component.

That said, Googling the generic OBDII fault code found this:


So it does seem to point in general to a failure of one of the Hybrid battery charging components, which sadly mean that this isn't likely to be cheap fix (unless the issue turns out to be a lose connector somewhere).

You can, of course, opt to drive it on the petrol engine only and ignore the issue with the Hybrid battery, though personally I would get it fixed.
 
In general, Red warning signs mean "don't drive" - Yellow mean "OK, but deal with it" -

But, a warning - Hybrid systems are high voltage, please don't go near them (I have a friend who's a trained HV chap, and he's been almost killed because something was meant to be supplied discharged and it wasn't.

Also, make sure wherever you take it to has the appropriate High Voltage skills (i.e not a general garage) or you'll be wasting your ££. You are in London so at least you have lots of choices of Mercedes dealers.

I'm suspicious that you've got a dying battery, and as markjay says "isn't likely to be cheap fix" - unless you are lucky !! I'd also take the view that unless you can find a Mercedes specialist who are claiming to be HV / Hybrid / EV specialists, for this one you need a Mercedes dealer who sees lots of these and will have that knowledge.. For instance, You do not want to be paying for a battery pack when that's not the problem, and no doubt software updates are the first step.

Sorry for all the warnings ....

Richard
 
Why didn’t you just book it in with the MB dealership purely to address the red battery issue?

Annual servicing: that could be done by an independent, but the red warning light: not so much.
 
To cheer you up, in general, warning lights mainly indicate that something's wrong with a sensor or, in this case, "potentially" a connection.

It could be a battery replace issue, but I'd suggest that the odds are that it's something simpler.

Just as an engine management light usually doesn't mean engine replacement, it's usually just a need to fix a bit.



("Potentially.." see what I did there ? Ah well, never mind....)

.
 
Hi. I’m new to this group and I hope someone can help me out please.

My c350e keeps showing the Red Battery sign + See Owners Manual.

It’s been consistently like that for the last 2 months now and I can’t use the Hybrid motor.

Last week, it started saying 12V battery critical on the MercedesMe App. Sometimes it wouldn’t start or go into drive or reverse.

I changed the big battery located in the boot (not hybrid battery). I thought this would solve all the problems but it didn’t. The red sign is still showing saying See Owners Manual.

Today, a mechanic plugged it into a machine and it came up with error code shown in the picture.

Can someone please help me out please because I’m lost for words and Mercedes Garage is fully booked for the next 2 months where I’m from.

I appreciate any help and I’m going to thank you in advance.

Thank you so much!
Hi

I have the exact same issue with my car currently.

I took it to a Merc dealership in France and they said something about the whole system which controls the electric flow needs changing (sorry never properly understood the issue as none of them could explain to me in English) which let's just say is an expensive fix.

However, scrolling around on Facebook and I find that my car possibly needs two software updates (the 2nd which could potentially be the cure to my problem).

Mercedes UK have said this is the case and have called me in for a free software update.

Fingers crossed. Do let me know if you manage to solve yours and I'll keep everyone posted about mine.
 
As for the error code, it's generic OBDII so it seems that the mechanic who scanned the car for fault codes is not a Mercedes specialist and does not have STAR diagnostic computer which is the Mercedes Benz tool.

STAR can scan all of the car's ECU and provide specific and detailed error codes (as opposed to the generic OBDII codes). It will also offer guided diagnostic that will allow the texh to pinpoint the failed component.

That said, Googling the generic OBDII fault code found this:


So it does seem to point in general to a failure of one of the Hybrid battery charging components, which sadly mean that this isn't likely to be cheap fix (unless the issue turns out to be a lose connector somewhere).

You can, of course, opt to drive it on the petrol engine only and ignore the issue with the Hybrid battery, though personally I would get it fixed.
It was the inverter. Thank you
 
Hi

I have the exact same issue with my car currently.

I took it to a Merc dealership in France and they said something about the whole system which controls the electric flow needs changing (sorry never properly understood the issue as none of them could explain to me in English) which let's just say is an expensive fix.

However, scrolling around on Facebook and I find that my car possibly needs two software updates (the 2nd which could potentially be the cure to my problem).

Mercedes UK have said this is the case and have called me in for a free software update.

Fingers crossed. Do let me know if you manage to solve yours and I'll keep everyone posted about mine.
Mine turned out to be inverter
 

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