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Comfort functions being shut off makes sense if the battery/charging is low. I remember coming across this info researching when I had a red battery warning.
Comfort functions being shut off makes sense if the battery/charging is low. I remember coming across this info researching when I had a red battery warning.
During that time is when I bought the Ancel bluetooth battery monitor which I think was handy for determining the alternator was fine and not the issue. Since its connected directly to the battery it tracks and records battery voltage even when the car is off. I was able to open the graph and see what the car was doing, see how the battery was being charged and being drained. But i also have my Foxwell obd scanner which wasnt showing any faults. I think scanning the car would be the first step.
@TimC300
It is never easy to pin point the root cause especially when random issues are hard to reproduce or trigger.
The ALT being ECU managed, many issues can act up at once begining with unstable networking CGW.
The fancy charging system is made difficult to troubleshoot. Poor charging control and battery drain don't help reliability. I know one thing that does.... "ALT-LIN!"
Last edited by CaliBenzDriver; Aug 24, 2025 at 01:10 PM.
That seems beyond my understanding of how things function. Took me 3 days to figure out I had a faulty ground wire in one of my fog lights in order to fix it.
At the time i had the fault code for the alternator I didnt have access to the manual. Just for fun I looked up that code and seems to point to the poly-v belt. Wonder if not running the car for a few days maybe had some condensation on the belt and it was slipping when first starting the engine? I live right on the water and I notice alot of times opening the hood and everything seems damp. For that code it mentions checking the LIN, wonder if thats what you mean?
Troubleshooting guide pointing at serpentine BELT at the source of trouble for ALT voltage chaos is overly simplistic.
Granted it's not simple but the ECU has enough data to know what voltage it is requesting from the ALT.
-- I'd say 1dt step is to collect evidence by driving with IC-Display to show battery sensor (VOLTS/AMPS).
-- Prevent drain by locking doors when car is unused.
-- Consider using an automatic battery float charger to fully charge batteries.
I am sure you won't miss the headaches from this beautiful car.
What is your next ride??
Sad end to this story. Considering this is the last of well engineered MB era i doubt i will ever buy another of their products. Such a fall from grace they have done.
Something reliable, back to lexus or maybe try a tesla. Theyre pretty much zero maintenance compared to a benz lol.
Sad end to this story. Considering this is the last of well engineered MB era i doubt i will ever buy another of their products. Such a fall from grace they have done.
Something reliable, back to lexus or maybe try a tesla. Theyre pretty much zero maintenance compared to a benz lol.
It's carefully engineered to deliver the ownership you are familiar with.
It's much like Boeing 787 Dreamliner powered by the GE90 turbo fans:
The composite carbon wings are delaminating and the engines randomly quit out of the blue - Even high-maintenance hardly helps.
"Made in JP" helped to dominate "designed in DE"
Last edited by CaliBenzDriver; Aug 26, 2025 at 02:00 AM.
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