Davetas

A couple of times, I will see red battery signal and elevated temperature indication of 185°F on the dash, my windshield wipers would cease, the horn would cease, the cooling system would not come on, the tiny dot red light by the transmission stick would be off, the headlamps and rear lamps would come on, the radiator fan would be blowing continuously independent of the thermostat.

Has anyone experienced this and would you know what the cause is?

Your suggestions would greatly help me and I will appreciate them.

I use a Mercedes Benz 2008 E350 Basic.

Thank you.

nd-photo.nl

The electrical system has a couple of components

- Is/are the batteries in good order? Get them measured to know for sure
- Is the alternator providing enough juice when running? If not, it can be alternator or the voltage regulator
- If batteries and alternator are ok, then it might be the BCM aka battery control module
- Other things to consider: bad earth strap(s)/earthing points

CaliBenzDriver

+1: this is really good insightful help.


In addition I would add that car may drain its batteries while parked.

When voltage is too low the weak electrical system is going to develop all sorts of electrical damages.
To prevent that use a smart CTEK float charger.

Don't guess diagnostics, measure voltages. A new battery may not provide lasting relief.

nd-photo.nl

You are welcome!

You are 100% correct, I experienced exactly that! I bought 4 new batteries (2x AUX & 2x Main) before I found out I had a power drain.

I dont know exactly how I fixed it, but I replaced a bunch of stuff (BCM, AUX battery relay, pre-fuse, alarm siren) and deleted some things (navigation unit, internal gsm phone, etc)

CaliBenzDriver

Congrats for your great results. These cars are amazing when they work well. Fixing them is an amazing challenge... "Diagnose Dan gixed it" from NL!
I feel more fortunate now not having BCM or ABC.


I had a bit of similar experience... the battery drain issue is incremental. There are big drains and many small drains. They are designed to collectively deliver the "MB experience" we are familiar with.

In my chassis, when the car is asleep the drain of system AGM is centered around security polling:
"Are the doors locked + closed?"
Crazy solderless Door Modules stutter through poor connections and make this extra long and power hungry process. It's no better when the car is awaken, still amazingly slow CAN-B straight from factory.
Same stuttering goes on with the engine CAN-C poor bandwidth.

nd-photo.nl

I bought a battery monitor (works via bluetooth). I can highly recommend these things, they are about 20 USD/EUR and they provide you with insight. Something like this:
https://mbworld.org/forums/c219/8443...ml#post8860681

CaliBenzDriver

this looks like a very handy piece of kit to monitor SOC. Nice BT Application

We're going to see how the battery gets drained gradually as a result of 1,000's extended laborious wake-up cycles.

Many modules are always powered ON but held in a low power mode. Not a problem!


If you want easy fun troubleshooting. You will need a scanner to reset faults you create:

simply unplug CAN-B modules a L+R bus distribution bars.

This will disable modules response to let them sleep perfectly well.

Proceed by halves to evidence L or R side circuits?

Scan whole car for faults prior to unplugging anything so we can gather what else maybe happening.


Don't ever let lead-acid starter battery drain, use a charger until working reliably.

elMacko

I wonder if these vehicles have the same 2 battery system on the R230..! If so, perhaps you also have a BCM..! Is that BCM the same used on R230's? A230-540-1045?
As you may know that BCM is the Aquiles tendon of the R230....! Would be nice to find a "safe and long lasting" retrofit for it! Mine recently burned and I am in a quest for finding a way to retrofit in my SL500.!

CaliBenzDriver

where is/was that topic being discussed??