beejAMG

Yep, this site has indeed chnaged since you became a member 12 years ago. People now are more helpful and more vocal with tips and advices that could actually help solve the issue.

Unlike you with 170 posts for 13 yrs! Wow! I sure hope it has changed!

Anyways, if you read before posting, OP mentioned that he got a new battery 6 months ago. So you think the battery is on its way out? Yeah right. You shouldve saved your next post for another year or two.

f4i 954

Wow someone's feelings got hurt, why would I post more, I leave it to the experts like you.

beejAMG

You havent answered my question but. OP mentioned that he changed his battery 6 mos ago, so you really think its goin bad? Maybe OP can use ten double AA batteries?

Useless member, waste of space if you ask me.

f4i 954

This is not the place for this, if you have a problem with what I said PM me and next time I take a sh*****it I will reply

beejAMG

Its a simple question mate yet you cant answer it. Save your "smart posts" til 2020. Maybe itll be useful, right now, youre just a waste of time and space here. Just keep lurking, that way people wouldnt know youre useless.

Diegobrings

Yeah all I did was ask for some help before going and spending money on something that doesn't need to be touched yet

kajtek1

The truths is that with today's technology things are so complex that you will always have several possible answers.
Troubleshooting towards one or other possibilities often can be based on miniature details that lot of owners will not be able to notice, while SD are unfortunately too expensive for DIY.
As I mention, I drove with such message for a week as it happen after leaving my home for vacations.
I have policy of starting with simplest things to do, even they might be lesser possibility than other.
So cleaning and torquing the battery connections is the easiest thing to do.
Testing the battery would be 2nd and having voltage display on the cluster you can do it by turning all the headlights and defrosters on battery power -observing how the voltage change.
Testing SBC battery would require tester, but lot of automotive places in US will do it for free.

2MERKS

Yes, I agree...I was just stating from what happened to my car. I have not
had the faults "cleared" yet, when I do get a chance to stop by my Indie it will be taken care of. No harm, No foul!!

thtguy

If your battery is 6 months old I would probably say your alternator is not charging at a high enough voltage. And not able to keep up with all the electronics in these cars. Easy test if you can start it. Connect a voltage tester to the positive battery terminal and the ground should register in the 14 volt range.

burgca

Thtguy I agree with testing the battery voltage (+14), Diego you may have a bad "new" battery (look at date on battery it does happen). You should be able to validate once you get the car started.

wjcandee

If you are in the United States, find your closest advance auto parts. Get the car jump started, and drive it over there. They will test your battery with the proper Midtronics tester that Mercedes recommends, and they will test your alternator. Those are two potential problems, regardless of whether the battery is 6 months old. It could have a dead cell or some other problem. That you had unhooked the battery the day before suggests that something in that process was a problem. Whether you didn't hook it back up correctly, or you shorted something in the process and fried something, it's all a possibility. But start with the simple stuff first. Advance will tell you whether it's the alternator or the battery, which are the two likely causes. Also have them check the SBC battery under the hood to make sure that that it is still good. Advance has an excellent group 49 / HH AGM battery if that's the problem. They also can find you a decent alternator, although if its the alternator and you want a rebuilt one, I would recommend only the quality-built remanufactured brand, which is available at the lowest price from carid.com. If you need to replace the little aux battery, advance does not have an AGM aux battery, although they have a regular aux battery that fits. If it were I, I would go ahead and order for my aux battery the Yuasa agm battery from Amazon. Get the real thing. Ytx14-bs. You also mentioned something about a problem with the radio. Is it the factory radio? Or did you have somebody install some other thing in there? Very often, the aftermarket installers run an extra wire back to the battery and hook it up outside the Mercedes power system. Sometimes, this shorts or otherwise creates a problem with battery drain and screws up the monitoring system.

Diegobrings

Can this problem affect my SBC system at all ?

MacVidMB-V8

This problem isn't worth living with when you can have an answer for $10.

Everyone should have one of these in their trunk or garage or utility room.


Set it to read DC Volts.

Put black probe on (-) terminal on battery. Put Red probe on (+) side.

Look at screen. When car is not running it should read around 12.5 Volts.

Start the car and it should read 14.5 Volts or so.

If these readings are both the same, your alternator or voltage regulator isn't working.

If these readings are correct but a day later your car is dead again, you have something that is draining the battery while car is off.

I had a friend who drove his mom's newish RX-8 over one day, he said the instrument panel was lighting up like a Christmas Tree. Brought the voltmeter down and it was kicking out 16+ volts while running. WAY TOO HIGH !. I told him to shut it off and call a tow truck. A quick google search showed that the problem typically led to a burned out ECU and instrument panel,. If he had driven home it probably would have cost $1,000s. Anything over 14.5 will burn up electronics and overcharge the battery, causing bubbles of potentially explosive gas.

Typically a dead or dying battery will start dropping from 12.5 the second you turn off the car and keep dropping below 12 within a few minutes. A good battery should stay at 12.5 for days.

It is easy enough to find a electronic drain by using the volt meter to do a load test and then remove fuse after fuse until the load disappears.

Point is, for $10 you can put an end to "I wonder why my battery is dead?".

ANd it is a great investment, if you dig through posts here you will find many places where someone replces a battery, then an alternator, or vice versa. A mechanic who does this will always say "It was PART of the problem" when it almost always is either one or the other.

Compare the cost of needlessly replacing either one versus $10 to always replace the right one.

The guy who mentioned loose cable or connections was right, I have seen that as an issue, especially in places with rain or snow & salt. Never a bad idea to clean corrosion and tighten the battery terminals. But you could even find that issue with a voltmeter.

Diegobrings

My SBC is running while my car is off

wjcandee

When you have an AGM battery, the proper way to test it is to use the Midtronics tester. Advance Auto Parts will do that for free, and will install a new battery for free if you need one. They will also tell you if it's the alternator (of which the voltage regulator is an integral part). That said, everyone should have a voltmeter for a million reasons.

wjcandee

You sure it's the SBC and not the airmatic pump? That will kill a battery pretty quickly.

The real question is whether your SBC (or airmatic pump) is affecting your electrical system.

I would quit fooling around and just take it to a good indy.

beejAMG

It will not affect your SBC, E320s dont have airmatic.

Bring your car to an indy and get it over and done with as soon as possible. Members can chime all their ideas and solutions but if youre not gonna do anything about it, it wont disappear like magic.

burgca

Diegobrings I agree with beejAMG you should get the car checked out by an Indy as soon as possible you can find one from Benzshops
http://www.benzshops.com/

bbirdwell

Easier to post schematics and info. Excerpt from the training file. G1 is main battery. G1/7 is auxiliary battery.

starbrite

Huh!, they most certainly do.

kajtek1

Thanks for posting.
The schematics show the program idea, but I guess there is much more behind it.
Per emergency mode, when main battery goes low, the computer switches off some customers, but supply the rest of electrical system from aux battery.
That means that in some situation the aux battery can be drained by lights, leaving no power to SBC ?
Tell me it isn't so?

bbirdwell

Check PM.

wjcandee

It isn't so.

Please just go to a mechanic already.

kajtek1

You wouldn't have other handle on this forum that starts with "P" ?
Would you be able to explain the answer?

beejAMG

this thread is goin way out of context coz OP wont get the proper solution which is go to an indy to have it checked. sadly, this problem is not a simple DIY where you simply replace a fuse or reset something with your key.

I had the same problem before from time to time and wasnt really bothered until the main battery gave (cant unlock the car much more start it) and i had to replace it. this warning has nothing to do with the SBC since that function runs mainly from the aux battery. the warning shows and shuts off non crucial elements/function on the car, lights, stereo, nav system and others, it will prioritize starting the car and being able to drive it safely.

now, OP said he has a a 6 month old main battery. this warning showed up, maybe its a defective battery like i said before or a busted alternator. but until OP gets it checked, we can all just speculate on whats wrong with it. have it checked or leave it as it is.