W211 BEAST

I searched and didnt find anything useful. I'm going on a long drive in about 30 minutes and I want to make sure whats wrong before I leave.

My instrument cluster says

"Low Battery
Conven. Functions
Turned off
Temporarily"

Or something along those lines.

Anything to worry about? What do I do? Why is it there?

chiromikey

either the battery will no longer take a charge or your alternator is not charging properly, most likely the second scenario.

...and YES there is something to worry about! if it's your alternator your car will suck the power out of the main battery and then the sbc battery. after that happens you will have NO BRAKES!!! DO NOT TAKE YOUR CAR ON A LONG DRIVE...i wouldn't even take it out of the driveway!!!

enzom

Was the car parked for a few days locked?

I would get that message if I did not use the car for more than 2 weeks. I found that activating the alarm (by locking the doors) caused it to happen in a week.

Once the car started, and the battery charged as I drove, it went away.

Jakpro1

If I was a betting man, I would go with battery giving up the ghost.

These things are notoriously bad. Warning if you are out of warranty, may wanna do some searching about aftermarket batteries......ones from the stealer could not be more overpriced.

Friction

Keep the roadside assistance number handy. As mentioned above, if it is the alternator, you will be stranded after complete failure of your electrcal system. YOU WILL NOT HAVE BRAKES or anything that is electrical.

Friction

FYI the convience functions are serviced via the smaller battery in the engine compartment, Seat heaters, radio, and fun stuff like that. I had the same warning as you mentioned when my alternator failed. It is EXTREMELY dangerous to assume it is just the battery, i was driving the car when it all failed with no brakes. Have the alternator checked before you get stranded or in worse trouble.. Fyi If it is just the battery, Autozone has the big (rear) battery for the e55 if needed at right around $100.

W211 BEAST

Thanks a lot for the help guys. I checked this thread last night on my iPhone and I took my friends car.

Hopefully I can go to the dealer on Monday.

aleksandar1099

So really funny, I just had the same thing go on my car!!!!!!!!!!!!!!!!!!!!

It said visit workshop with a pic of the battery only on WOT, and after I brought it home and left it running outside for about 5 min, I came out to beeping and everything red saying, battery/aternator...stop engine

it wouldnt start at all and says the same thing.

I charged the small battery in the front to try and diagnose the problem, and it started! I am getting a new small batt tomm and see if that fixes the problem...

does autozone carry the small batt? I dont want to pay $240 for it from the dealer!!!!

E55-0817

Autozone, Pepboy, Checkers, they should all have them. I just replaced my aux battery (the small battery) about 2 weeks ago. I got the battery picture along with the visit workshop message. Well, problem solved after I changed out the aux battery. Make sure you get the battery that have AGM (Absorbent Glass Mat). I got it for under $90 at Autozone. I hope this would help.

aleksandar1099

Thanks man, do you remember the size?

regor60

I had the same messages, along with terrible burning smell.

Immediately stopped the car in the middle of the road. Flatbedded to dealer, alternator replaced.

vinnyz

i had the samething happen to my car it was the alternator and the battery control module .. the battery control module blew out and then fried out my alternator... i had my alternator rebuilt instead of paying 1k that cost 170 and the battery control module was like around 400 ...

E55-0817

NP. It should be 14. Or you can always take your battery out and bring it in.

aleksandar1099

well, I just bought a new batt from the dealer ($144)... And it still comes up with the same message under WOT ... So off to the dealer on Monday!

vinnyz

it's one of 2 things alternator or battery control module . or it could be both like what happened to my car

.trunzx

I'm having a similar problem. I get the "Conven. Functions Turned off Temporarily" message but it doesn't say "Low Battery". I noticed that all the lights on my car pulsate, which leads me to think it might be the voltage regulator. I checked the batteries and both are good. I've read that the alternator itself is pretty bulletproof however the voltage regulator is known to go bad.

Is it possible to replace the VR without removing the alternator? Anyone know how to remove the alternator if not?

TopGun32

the alternator seems to be faulty after reading a few threads about batteries.

I had the battery message recently, and I took the car to Sam's and replaced the rear batter for $90 installed.

The front battery connection was a bit loose and I just used a wrench to make sure it was nice and tight. But I will replace soon, just in case.

No more messages.

I find it really alarming that the alternator would quit and shut down power to the car while driving.

Is there a way to tell which type of alternator is faulty (part #)? I'm sure if MB knew that people could get in serious danger with a part that might fail while driving, it would be considered a recall.

They went through the trouble of recalling a gas tank line that could crack.

While I don't dispute the alternator has caused issues to some members, dealers always want to juice the situation and charge for things that are related.

gambari

Gang,

I just had a similar situation with my car. The message was polite intially (and not unsusual), for about a day and then today it got nastyand unusual; the display turned red, alternated beween the battery symbol and a message to stop driving the car/brake loss, alarm beeps went off and stayed on all the way to my mechanic. We checked both small and big batteries and found the former to be okay, but the latter had been drained (11.1 volts). We switched with a new battery in the trunk and the aggressive messages came back almost immediately. Further diagnosis suggests it the Voltage Regulator ($47.00) and not the alternator. The car should be done tomorrow and I will update at that time. Hopefully, it is that simple.

Busta Riles

I had my car in the shop for a few weeks and the same light came on when i was pulling it out of the shop. We brought it back in, charged the main battery in the trunk, and it's been fine ever since.

TopGun32

can you post part number? or a portion of your service invoice.

.trunzx

Heres the part # for the bosch VR from allmercedes.com

http://img19.imageshack.us/my.php?image=19109440.jpg

aleksandar1099

So I got my car back today and they did a few things.

First they replaced the voltage regulator, but it had the same problem, so they replaced the entire alternator.

It ended up costing $1100, once again, thank god for easy care!!!!!

.....And if anyone was wondering, when the car notices that the alternator is going bad it raises the rev level at idle, so it feels like it is driving really rough...

gambari

I wish you were wrong, aleksander1099, but you are right. I replaced the rear battery no luck, then replaced the Voltage regulator and it seemed to work but 30 minutes later the messages were back. Now we are going to replace the Alternator. My original battery was still okay I guess, and but not the VR. I get my car back next wek Monday/Tuesday and I am sure I will be about 1500 lighter. Darn it!

aleksandar1099

Sorry to hear man! I am still SOOOOOOO glad I bought the extended warranty!!

Friction

Well, we know what the end result and temporary fix is. But what causes the problem in the first place? I can only assume it will happen again since so many of us have had the exact same problem.

How do we handle this on going???