Let me start by saying i haved searched but havent found my exact answers

Basically i have an 05 e55 and this message pops up on and off constantly.. literally is says low batttery, convenience funcitons unavailable.. 30 seconds later it would say convenience available again..Then back to being unavailable. Back and forth it does this constantly while im driving and its not always 30 seconds... Its very random (30 sec, 5 minutes etc..). I have never gotten a red battery on dash, nor has my car experinced any power issues..

I have changed my auxillary battery, main battery and voltage regulator.. Still no change

I have tested out the output on my altenator. 14.0-14.1.... With as much accessories as i can put on, the voltages doesnt go below 13.8... Driving around in dyno mode... I get 13.9-14.0.. The front battery tested at 12.7... The rear battery was tested at autozone... Results were good..(its brand new so it should be). I have been driving like this for a solid 2 months now.. So i believe its not the altenator


When the message pops on and off the voltage doesnt ever drop, so what could be making the message pop up.. The next thing i was thinking about changing was the bcm..... Im running out of ideas...is there like a reset or something i can do

Every searched popped with people actually having low voltage readings... But has this happen to any of you with good voltage readings, good batteries etc..?

 

How new is your Aux. battery? When those get old, it tends to throw the message.

 

Both batteries are about 2 months old. Bought them the same time

 

Replace the Battery Control Module (BCM) that should solve your issues. Especially if it's the original BCM

 

Ill order one next week... Also does anyone thing this could have anything to do with the "sam" unit... Now readng and learning a little about it

 

Yes

If the Alternator is putting out the correct voltage and current, and the batteries are fresh the issue is usually a BCM, and that's what you have

 

This thread caught my eye as I just saw this message for the first time a couple nights ago. I was actually trying to get rid of the SOS TeleAid Malfunction message.
I followed a tip on BenzWorld, to turn the headlights on for 2 minutes to run the battery down a bit. When I turned the ignition back on to recharge the battery, I briefly saw this "Low battery, convenience functions unavailable" message, but the SOS TeleAid Malfunction went away and I've not seen the Low battery message again either, so I'd say, Try it:
1) Turn key to position 1.
2) Turn on the headlights for two minutes.
3) Turn key to position 0.
4) Turn key to position 2 to start the car.

 

Does the bcm have to be programmed via star or is a simple swp

 

So i went to a indy to get a star reading... Hear is some fault codes

 

 

Im guessing this means my battery relay is bad

 

yep, theres a small chance it may be something else, but change the relay first.

 

Another update.. Changed the relay.. Still no diffrence

I have reading diagrams and the way my car has been acting.. Im starting to believe its a wiring problem.. Im going to run a signal wire from the bcm to the battery relay to see if that solves the problem... Also i will try changing the poly fuse.. Anybody knows the part number for the poly fuse

 

sounds crazy but are you sure the connections on your battery are tight. i was getting this error and one of the connections at the terminal was just slightly loose, tightened it down that corrected the issue

 

I am glad to see this thread because I have experienced something similar. I have new main and auxillary batteries and get this message when I don't drive the car for a week or so. I was wondering if it was my alternator before this thread, but now I wonder if it could be something else. If it is the alternator, does anyone know it it would be covered by extended warranty/

 

I'd imagine most all aftermarket warranties would cover the alternator.

 

Any of you guys have lowering modules?

 

That is a different and common issue....The AUX battery voltage has dropped below a certain threshold. Once you drive the car for a bit, the battery will be charged again and the message will disappear.

 

Thanks. Are you saying problem is with the alternator or the aux battery? The Aux battery is new and should go at least a week without needing a recharge?

 

The AUX battery is weak to begin with and the draw over a week can bring it down...It is no big deal IMHO, just a PITA for ~30 seconds or so and then it should be fine...

 

Help!!!!
Hello everyone, can someone please provide some feedback on this tread, last night while idling my E55 in the garage I smelled a faint burning scent, popped the hood and could not find nor describe the source of this burning smell, however, after checking the forum on the matter it's come to my attention that the alternator/voltage regulator could be on it's way out, convienience message comes on and off now so i know there is low voltage (11.1v) sometimes a bit less, here's my question,,, if, it is the regulator thats bad, would I still get the burning smell???? Or is the burning smell a clear sign that the alternator itself is toasted internally....feedback please!!!!!!!

 

Help!!!!
Hello everyone, can someone please provide some feedback on this tread, last night while idling my E55 in the garage I smelled a faint burning scent, popped the hood and could not find nor describe the source of this burning smell, however, after checking the forum on the matter it's come to my attention that the alternator/voltage regulator could be on it's way out, convienience message comes on and off now so i know there is low voltage (11.1v) sometimes a bit less, here's my question,,, if, it is the regulator thats bad, would I still get the burning smell???? Or is the burning smell a clear sign that the alternator itself is toasted internally....feedback please!!!!!!!

 

Just a little update... So as of now i have replaces

Auxillary battery
Main battery
Aux battery relay
Voltage regulator
Battery control module...

And still i get the low battery message... Its in the shop right now and they are going to test it for a draw... At this point im ready to just sell this car and get a m5

 

Did you ever get a chance to drive the car around with the voltage screen on the dash? Would the car drive ok for a while then throw the message and voltage starts to drop?

 

Suppose the indy has solved the problem.. It was my amp... And. $1300 bill not incuding replacing the amp...i told him leave the fuse unplug... Im not going to replace another part, and thats not the issue.. Going to drive around without the fuse to see if it comes on at all