auxiliary battery malfunction
10-02-2018, 01:19 PM
#26
Senior Member
I have never seen a description from MB about how their charging systems work and that would be very helpful. Always remember that it's not just the alternator and the battery, but everything between the two that ALSO matters. Small amounts of corrosion can make a HUGE difference in battery charging (and other circuit performance issues). They ALL need to be in good electrical condition.
10-02-2018, 02:54 PM
#27
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2014 E550-sold 😩
Hello, I have a 2014 E550 4Matic with Eco Star/Stop and Distronic Plus. I got the "Auxiliary Battery Malfunction" warning a few weeks ago and it hasn't gone away. My break hold, eco stat/stop, and distronic plus does not work now.
My Aux battery in the trunk has about 13V. I've been looking on the forms and a lot of people say that it's not always the battery, it could also be some kind of voltage converter or capacitor that is malfunctioning. Also another user mentioned the voltage of the battery could be good but the internal resistance could make it fail.
Any suggestions? on what to do?
My Aux battery in the trunk has about 13V. I've been looking on the forms and a lot of people say that it's not always the battery, it could also be some kind of voltage converter or capacitor that is malfunctioning. Also another user mentioned the voltage of the battery could be good but the internal resistance could make it fail.
Any suggestions? on what to do?
10-02-2018, 02:58 PM
#28
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2014 E550-sold 😩
10-02-2018, 03:14 PM
#29
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As info, my wife just returned home from playing Pickelbal and the aux battery voltage was 13.08 - engine not running and off for about 5 minutes. 2016 E350 Sport.
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KEY08 (10-02-2018)
10-02-2018, 03:40 PM
#30
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2014 E550 4Matic
Is there any way I can test for sure that it needs to be replaced. I looked around and many people said that they replaced their battery and nothing changed, I'd rather not spend $135 on a new battery if I still will need to replace a voltage converter or something.
10-02-2018, 04:04 PM
#31
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2014 E550-sold 😩
These generally indicate the battery is on its way out. Have you ever replaced this battery in your 5 year old car?
10-02-2018, 04:05 PM
#32
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There is no other voltage converter. Some newer cars like the 205 don't have a battery at all, but a capacitor in it's place. The 212 isn't like this. replace the battery and it will go away, I always clear the faults, not sure what happens if you just replace the battery without removing the codes it sets in the SAM.
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KEY08 (10-02-2018)
10-02-2018, 05:14 PM
#33
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10-02-2018, 06:42 PM
#34
Senior Member
Sure. Most anyplace that sells car batteries should be able to test your battery AFTER it is fully charged. Testing a non-fully charged battery gives you very un-reliable results. Walmart uses fairly sophisticated testers and does this testing for free. Other auto parts stores have other testers and do not charge $$..
10-10-2018, 07:02 PM
#35
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2014 E350 4M Diamond Silver
Do Aux batteries for W212 and W213 are same? I saw some parting out threads for cars, can I buy them for my 2014 E350 Aux battery replacement?
Thanks.
Thanks.
