Driver's display warning.

Center display warning.

On days when the temperature drops below 30 degrees Fahrenheit, I receive a warning in the driver display of my 2022 S-580 (USA specification) that says: "Stop Vehicle: See Operator's Manual" after the first start of the day (i.e., the car has been sitting overnight and all systems are cold). When I press the "Ok" button on the left side of the steering wheel to clear the driver display warning, I get a message in the center console screen that reads: "Stop Vehicle See Operator's Manual: The 48 V on-board electrical system is malfunctioning. Stop the vehicle in accordance with traffic conditions. Do not continue driving. Contact a workshop. I have attached pics of both the driver display warning and the center console warning.

Despite the admonition not to drive, I have driven the vehicle after it has warmed up to operating temperature. The vehicle drives normally. The Eco-Boost, which relies on the 48-volt electrical system, seems to be working normally. The driver display gauge shows that Eco-Boost is charging when decelerating and braking, and dis-charging (i.e., adding boost) when accelerating quickly. After the initial start of the day, if I drive to a location, park and return after about an hour or so and re-start, I no longer receive any error message. In fact, the car behaves normally in all respects until the next time the temperature drops below 30 degrees Fahrenheit, and I am starting the car for the first time after a minimum of 8 hours overnight.

I have taken the car to my local dealer and the mechanics can't seem to find anything wrong. My service adviser says that they will try some software updates/re-flashes to see whether that fixes the problem.

Has anyone else had this experience? Did you find a solution?

 

Did the update solve the issue? This is a common issue with the GLE, there are cases reported on the forums of the W223 having the 48V issue still, just some.

 

The dealer performed a software update for the 48-V system. It did not correct the problem. I have not taken the car back because it has warmed up in my area and I can no longer reproduce the conditions that trigger the fault. We’ve had only one cold condition since the car was returned and it did display the same warnings under the same circumstances as before. That is why I say the update failed. Since then, it has been too warm to cause the fault. I suspect that since this issue is not widespread, that software isn’t the issue. I would guess that the issue is with a faulty sensor that is temperature sensitive. I guess I will have to wait until next winter to explore this problem again.

 

This is interesting -- my understanding is that the 48 volt battery is housed in a temperature stabilizing enclosure that keeps the battery within an optimally functional range. Batteries neither charge nor discharge effectively below 30F and above 80F. If you encounter problems this summer in high heat, the problem could be the thermal jacket. Your dealer will not order a replacement unit without a confirmed failure due to its cost, and the replacement will arrive from Germany whenever.

 

I had a similar problem about a year ago. It reappeared periodically. On the recent 2 year service I insisted the dealer replace the battery. Initially they resisted but were able to replicate the problems I had a year ago and they ultimately replaced the battery under warranty. Hopefully this resolves the issue.

 

Could be related...I keep getting 12V system critically low warnings. Have the Faraday key fob pouch, always lock the vehicle and all that stuff. Yes, I drive and hour a day, 40+ miles, but suspect the 12V AGM battery has a bad cell that will get replaced under warranty. Been charging it externally lately Have had that 48 V warning pop up and reset on its own once or twice as well.

I personally serviced the vehicle and finally got the service reminder to reset via the "workshop" menu on the steering wheel. A bit late, but MB starts sending you nastygrams if you let it go longer than 30 days. Its almost like they randomly change the workshop menu access procedure or I just plain forget it.

While I was in that "workshop" menu, I was able to view the status of several systems including the 48V system. It stated that the 48V battery was at 32 degrees F when it was 65 ambient. The 12 V battery temperature reading was more correct at 62 degrees. Could be something with the 48V temperature sensors?? Hmmm, if the 48V system thought it was below freezing it may not recharge as aggressively? Not sure as I've yet to have it in for warranty / recall stuff


Odd it would pick/ default to 32 degrees F to display when it was in the 60's outside,


and whatever error 22 means on the 12V side. Any ideas?


One of these days, I'd like to see if I can drive the vehicle with the "workshop" mode displayed and if you can scroll thru stuff at the same time.

Here's a link for the workshop menu access. Since this video is for a left hand drive vehicles, you would be using the buttons on the left side of the steering wheel for right hand drive USA W223's. But the critical timing is right. Don't ask me how, but I got this one to work for me. Thanks

 

My understanding is that the 48 volt battery is enclosed in a temperature stabilizing jacket, but 32F shouldn't be the stabilized temperature.

 

Just because they said they couldn't replicate something, I'm assuming that in a vehicle with so many electronic modules that all faults and error messages are stored in non-volatile memory outside the OBD-II. Take the service reset procedure "It Cannot Be Undone" straight from MB. They would be able to see exactly what and when any errors occurred. Just like they can log when the oil has been drained and refilled. Not saying this is fact but I believe it to be.

 

This is good to know. Do you know where the 48V battery is located? Is it inside the cabin under the rear seat? I have not had any problems with the 48V battery warning during very hot days. I have noted, however, that on very hot days the car will cool the interior when no one is inside. I thought perhaps this was a convenience feature for the driver and passengers to reduce the amount of time required to cool the cabin after the vehicle is started on a very hot day. It didn't occur to me that the cooling might be a 48V battery self-preservation feature. On very cold days, the car does not automatically warm the cabin with no one inside. It seems odd that the car cools itself on hot days, but doesn't warm itself on cold days.

 

I think the 48V battery is in the engine compartment near the firewall. I'll have to check. The 12V AGM battery is under the floor in the trunk.

The 1.5V AA batteries are located throughout the vehicle haha: