auxiliary battery location RHD w212 e220cdi estate 2010

[lewiseyers]

Hi all,

would love your help and advice,

im stumped, i cant find the auxiliary battery in my right hand drive e220cdi, 2010 automatic, has my car actually got a auxiliary battery or have i got a duff main battery or alternator

its not in the driver foot well or the passenger footwell or the boot or behind the instrument cluster,

last night a big round red battery warning appeared in my speedo centre, after some investigating ive found this is proberbly the little known about auxiliary battery,

the symptoms were

the warning light mentioned

steering got heavier?

poor starting and eventual failure to start

poor operating of the gear box and all electrical systems

i replaced the main battery in the engine compartment in the summer for a new bosch one now 6 months old...if id of known id of done both batteries, i charged the new bosch battery all afternoon and only managed to get it from 11v to 12.07v on the multi meter.. this is being returned tomorrow under warrantee for a replacement


were is this auxiliary battery located...i need to replace it and continue trouble shooting

 

[cheddar]

I think if the aux battery fails it actually says that on the dash, it did at least in the last one I did. And that one (61 plate) was up behind the dash on the far right hand side.
Does your car have stop/start?

 

[whitenemesis]

Don't guess at it, get the codes read ..

 

[lewiseyers]

I think if the aux battery fails it actually says that on the dash, it did at least in the last one I did. And that one (61 plate) was up behind the dash on the far right hand side.
Does your car have stop/start?

My car does not have stop start...

There is no battery under the dash....

 

[lewiseyers]

Don't guess at it, get the codes read ..

Was asking were the auxiliary battery is located so it can
be renewed regardless ....not shall I get codes read... I can go that at work....

I did use a BASIC reader at home... found no codes...

 

[lewiseyers]

The only warning on my dash is a hide round red warning with big red battery symbol...no writing...

I RE charged the new Bosch battery all day only got 12.07v in to it...car would not turn over...

Put a old Renault Clio battery on started straight away... battery light went out, small yellow gearbox symbol stayed illuminated on dash tho...

I'd like the auxiliary battery replaced for piece of mind....new main battery going on later today too

 

[Diesel Benz]

Since the 2010 does not have stop/start, it only has the main battery and a very small "selector lever backup battery". It is under the dash as mentioned already. On a LHD car it is at the left side of the dash, pretty difficult to see unless you know the location.

 

[lewiseyers]

I have had all dash panels off, there are no extra batteries....

New replacement main battery now replaced under warrantee, as it failed after 6 months use...

I'm gonna fit that later after I finish work....

Thanks for the diagram..

Mercedes Benz recon there's no auxiliary battery, as I don't have stop start too...

As for the gearbox selector battery I've yet to find that either...

It's could be the gearbox battery I need

 

[lewiseyers]

Brand new battery in
12.16v at rest
11.6v when engine running!

Wondering if auxiliary belts broke...to dark to see at the moment....

Car had no fault codes last week at all

Fault code details I'm looking in too at the moment since this issue are

P0562 system voltage low
$7E9:engine


P0272 cylinder 4 contribution balance
$7E9 :a/t

 

[alanjm99]

I'm my S212 the aux battery is in the boot, took me ages to find it

 

[lewiseyers]

I'm my S212 the aux battery is in the boot, took me ages to find it

Mercedes dealer confirmed my car does not have one due to not having stop start

 

[Diesel Benz]

I'm my S212 the aux battery is in the boot, took me ages to find it

Your model year must be later if it has stop/start.

 

[Diesel Benz]

Mercedes dealer confirmed my car does not have one due to not having stop start

The small battery I was talking about is not for stop/start but the electric gear range selector. However the thread title talks about a 220 CDI, you probably have a gear stick at the centre console (5 gear automatic transmission or could even be manual transmission, we often forget that option), not the lever next to the steering wheel? The mechanical gear range selector does not need the small backup battery (obviously the manual transmission either, backup power is provided in a different way).

Sorry about missing the important information that was properly posted.

 

[lewiseyers]

I have 5 speed auto..