hpV12

The beast is officially offline. Had it scheduled for mods @ Benzwerks in HB on Monday, seems my 10 seconds will have to wait. Hopefully someone has some insight on what the problem is.

I've been dealing with a "low battery" icon for months now. Replaced the main battery with a Braille 15lb, icon went away. Only to come back, this time with a screen displaying "conventional features offline low battery". And at other times, it displays "Batter/Alternator Turn off engine" or something along those lines. And yet today, it wouldn't start period.. Instead displaying the aforementioned warning and even invites me to further explore the depths of my bank account with a "low brake pressure start engine" warning. This is new..

Thoughts? Will try to jump the car later, just wanted to know if anyone knows of a possible correlation between the brake warning and the battery. She was scheduled to also be fixed on Monday, along with the upgrades now not so sure... Will depend on how pricey this fix will be.

Also, don't know if this had anything to do with it but being aware of the battery problem, I decided not to drive this past week instead opted for my daily figure I'd save getting stuck on the road should anything happen. It was working perfectly when I was driving everyday. Left it to sit and there you have it.

Thoughts? Thanks in advance guys.

desired_speeds

alternator or voltage regulator!

hpV12

Any ideas on what either these would cost? I take it this would just solve the battery issue.. Brakes just coincidentally lost pressure at the same time? Good thing I wasn't on* the road.

AMGPilot

You do realize that you brakes are ELECTRIC that's why your brakes failed you ignored the cars warnings

Putting a liteweight battery especially in a car that is having battery issues is Foley.

Fix your charging system first, you need a new battery isolator and both batteries

Next time your car gives yo a battery warning take it seriously

desired_speeds

if its the voltage regulator its only a $40 part. If its the alternator it'll be a few hundred $. Make sure both front and rear batteries are healthy. Id say try a new voltage regulator first then if its still not charging then probably will need a new alternator.

AMGPilot

Nope car needs a new BCM

hpV12

I realize they are electric, but if the car won't start why/how is it even giving me the brake warning?

And let's not point fingers at Braille or other lightweight batteries. I've had them in numerous cars over the years and never had an issue. I also took the warning seriously, but had a ton of work on my plate to deal with. I scheduled it as early** as work allowed.

AMGPilot

to tell you to not do what you are about to try

hpV12

BCM?

AMGPilot

Battery Control Module

hpV12

A check of the forums indicates most people feel its the alternator or voltage regulator... Any particular reason you feel it's the BCM?

Manuyc

Wish you the best but I would have made sure to put a real deal battery in there.. These cars are not to be short changed in anyway, sorry!
However I would change the bcm and go from there

AMGPilot

Because of all the symptoms you posted. Put in a real battery (Wanna save weight? short fill the tank 4gallons) and Change the BCM. Also change the SBC Battery under the hood.

Job done

hpV12

I'll bet my bottom dollar it's not the Braille. This was an issue I had before the Braille. Will see what happens Monday.

Thanks for the help guys.

hpV12

Braille is a real battery.

I highly doubt I'm the only E55 owner running a Braille. But thanks for your input, will be checking the SBC and BCM when it's in the shop Monday. I'm pretty confident I can keep the Braille and still have the car functioning as it should.

AMGPilot

I love the people that figure the best place to save weight is with a battery.... These are cars that are brutal on the electrics there is a reason we have a 220amp alternator

there are better places to save weight than the battery ESPECIALLY on a street car

hpV12

Care to put your money where your mouths at? How about a friendly wager? 1k through paypal yours if Monday it turns out to be the battery. I'm taking it to Serge @ Benzwerks, I can have him chime in on the thread as a 3rd party. If its not the battery, you Paypal me 1k.

Easy way to take money from some clueless individual such as myself, que no?

chawkins2001

you got any codes? I will hit you tomorrow via text with the possible causes bro.

hpV12

I do not have any codes. Will wait for your text, thanks bro.

PACougar

Prada I have a AGM for racing it's made by the company that Braille put their stickers on. It's not designed to keep up with all of the electronics in these cars, I'm not saying that caused your issues but it may cause some in the future.

E55Greasemonkey

Trying to diagnose a battery/charging system fault on a complex car over the internet is silly at best. I have seen nothing but problems with these cars when customers bring them in with aftermarket batteries. They are EXTREMELY sensitive to voltage. When diagnosing these faults in the shop our first recommendation is installing the proper FACTORY battery. Then, you can properly check the alternator output and BCM functions. The original battery is a glassmat deep cycle battery. Your "convenience features offline" warning is the car telling you the battery has low voltage, and the car is shutting off non safety features such as seat heaters and A/C blower to conserve power until the voltage is at proper levels. The small battery underhood is the backup battery for your SBC braking system, in the event the main battery and/or alternator fail, you still have brakes. Your car may have multiple problems including a faulty main battery, alternator or regulator, or BCM. Charge your main battery, and your car will start, providing that battery is good. Some batteries once they go dead flat 2 or 3 times are ruined. The red brake warning in your cluster is likely the result of extremely low voltage throughout the car because of your dead battery.

AMGPilot

DING!!! Thanks for the post

AMGPilot

Well look who has a little dick.....

You don't understand the electrical loads in these cars but hey you're the expert that has the problem....

hpV12

You seemed so confident, if your equating standing behind your lecture to small penises then I know to just put you on the ignore list. Next time, keep it to yourself.

hpV12

Thanks for the input. We will see on Monday... But as I said guys, I've had a Braille in everything. 65s, 55s, 600s and not a problem. Just this one. Maybe I have been lucky with the other cars, but that to me seems a bit of a stretch.

Edit: GM, I was able to jump start the car. Audio system works, brake message went away... Business as usual. My "expert" guess still is alternator or voltage regulator.