our 350 e sedan suddenly shows in speed domenter Aux. battery malfunction.I checked O
Thread Starter
Newbie
Joined: Sep 2017
Posts: 1
Likes: 0
2010 MB 350E
our 350 e sedan suddenly shows in speed domenter Aux. battery malfunction.I checked O
2010 MB 350E suddenly shows Aux.Batt. Malf. in speedomenter unit. I checked hoses,OK checked belts,OK, checked TEMP OKIs it a problem to drive to get checked and fixed, what could have happened?
Newbie
Joined: Jul 2018
Posts: 1
Likes: 0
E350 2014 MB
E 350 Auxiliary battery malfunction
I have a 2014 E350 Mercedes-Benz with 39,000 miles on it auxiliary malfunction came on about 30,000 miles today I decided to check the battery in the trunk. I removed the two terminals making sure they don't touch metal I checked all the fuses which were all okay I turn the car on with the battery disconnected it still says auxiliary battery malfunction I put the battery back on shut the car off make sure the terminals on the battery was tight started the car now auxiliary battery malfunction warning is gone and my my Eco light came back on. I think the issue was the terminals get loose after a while I did a voltage test on the battery while it's disconnected and it was reading 13.9 volts which is pretty good.
MBWorld Fanatic!
Joined: May 2015
Posts: 4,037
Likes: 1,012
From: Miami, FL
2003 CL 600
It checks internal resistance of the battery, it will fail again soon. Every one we replace under warranty has plenty of voltage, I've tried out of my own curiosity to clean the terminals and re-tighten, clear the codes, and it comes back usually on the next drive cycle.
Just replace it, it's not an expensive battery or difficult to replace. The S class one is slightly more inconvenient to change but is the same physical battery.
Just replace it, it's not an expensive battery or difficult to replace. The S class one is slightly more inconvenient to change but is the same physical battery.
Newbie
Joined: Sep 2011
Posts: 6
Likes: 1
From: Bournemouth
2014 W212 E350 Estate Bluetec sport
I replaced mine with this:https://www.ebay.co.uk/itm/Genuine-L...53.m2749.l2649
Had no issues, i even swapped the sticker with the MB part number on, so it looks the same, only difference is you don't need to connect the clear air tube on the side as this one is a gel battery.
Had no issues, i even swapped the sticker with the MB part number on, so it looks the same, only difference is you don't need to connect the clear air tube on the side as this one is a gel battery.
