Aux battery malfunction. Cruise and distronic quit
Thread Starter
Senior Member
Joined: Sep 2007
Posts: 368
Likes: 11
From: Iowa
2019 S450
Aux battery malfunction. Cruise and distronic quit
Any Idea why all at once I loose distronic etc after a message saying Auxilary battery charging malfunction.. Could it be a fuse? but then the question why did the fuse blow. Car is in warrantee but Dealer cant provide me a loaner and if its just a fuse maybe I can cancel my appointment. 2019 S450
MBWorld Fanatic!
Joined: Nov 2004
Posts: 1,121
Likes: 86
From: West Plam Beach, FL
'16 S550 Coupe, '11 Lexus LS460, '02 CL500 (SOLD)
When batteries are not fully charged, the car will begin shutting accessories down to keep the car going. Doubt the problem has anything to do with a fuse. A little early for this battery to go but you never know.
Does the car sit a lot?
If you bought the car from this dealer and they won't provide a loaner, I'd find another dealer. Funny I also have a Lexus and they provide a free loaner for any car brought in for service.
Does the car sit a lot?
If you bought the car from this dealer and they won't provide a loaner, I'd find another dealer. Funny I also have a Lexus and they provide a free loaner for any car brought in for service.
Last edited by Jud Chapin; Apr 10, 2021 at 11:13 AM.
Junior Member
Joined: Apr 2020
Posts: 17
Likes: 0
2018 S560 & 2002 ML320
Similar issue to my vehicle. Purchased a 2018 S560 and the aux battery malfunction indicator came up Mid 2019. Dealer replaced the aux battery since it was still under warranty. Mid 2020, aux battery malfunction light came up again. Dealer again replaced the aux battery. Not sure why my aux battery keeps dying. Dealer isn't sure either. Fingers crossed that I won't have any problems this year.
Thread Starter
Senior Member
Joined: Sep 2007
Posts: 368
Likes: 11
From: Iowa
2019 S450
This dealer is 50 miles away. The other dealers are over 200 miles away.. This dealer claims that all the loaners are spoken for. A whole lot full of cars and they cant find one car for me to drive to a Dr . apointment on the same day in thier city.. A previous post was right on that the Mercedes service is on a slippery slope downhill!
Thread Starter
Senior Member
Joined: Sep 2007
Posts: 368
Likes: 11
From: Iowa
2019 S450
Car is a daily driver.. I suppose that the little 18AH Gell Cell could have died.. What I cant understand is as long as main battery is functioning normal why the Aux Battery is needed while car is running on main battery.
Super Member
Joined: Jul 2007
Posts: 742
Likes: 228
From: Santa Barbara, CA
S550C4, Porsche Cayenne
This dealer is 50 miles away. The other dealers are over 200 miles away.. This dealer claims that all the loaners are spoken for. A whole lot full of cars and they cant find one car for me to drive to a Dr . apointment on the same day in thier city.. A previous post was right on that the Mercedes service is on a slippery slope downhill!
Junior Member
Joined: Apr 2020
Posts: 17
Likes: 0
2018 S560 & 2002 ML320
From my understanding (I may be wrong) the large main battery is used to start the massive engine. The aux battery is reserved for electronics, sensors, etc. Thus, if the aux battery is low, the sensors that are needed for active cruise control will not receive the proper voltage
Trending Topics
Junior Member
Joined: Nov 2019
Posts: 58
Likes: 11
S500 4matic L
From my understanding (I may be wrong) the large main battery is used to start the massive engine. The aux battery is reserved for electronics, sensors, etc. Thus, if the aux battery is low, the sensors that are needed for active cruise control will not receive the proper voltage
Would love to see one if someone have a could possibly share this then would easy to make statement what is powering what and in what condition.
zender
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
MBWorld Fanatic!
Joined: Oct 2018
Posts: 3,360
Likes: 1,526
From: Washington DC
No more MB:(
When batteries are not fully charged, the car will begin shutting accessories down to keep the car going. Doubt the problem has anything to do with a fuse. A little early for this battery to go but you never know.
https://www.youtube.com/watch?v=3O3L8tlZS8U
Does the car sit a lot?
If you bought the car from this dealer and they won't provide a loaner, I'd find another dealer. Funny I also have a Lexus and they provide a free loaner for any car brought in for service.
https://www.youtube.com/watch?v=3O3L8tlZS8U
Does the car sit a lot?
If you bought the car from this dealer and they won't provide a loaner, I'd find another dealer. Funny I also have a Lexus and they provide a free loaner for any car brought in for service.
Junior Member
Joined: Apr 2018
Posts: 74
Likes: 10
From: Pittsburgh, PA
2015 S550 Executive, 2017 Volvo XC60 R design, 2009 BMW Z4 35i DCT TwinTurbo
Just did it this morning on my 2015 s550. Watched Youtube video, pulled aside the right liner, moved fuse panel, after disconnecting battery it slid out the top of the container, put new one in, connected up, replaced fuse bank, put back liner and all other bottom covers all in about 45 min.
MBWorld Fanatic!
Joined: Nov 2004
Posts: 1,121
Likes: 86
From: West Plam Beach, FL
'16 S550 Coupe, '11 Lexus LS460, '02 CL500 (SOLD)
You are right, places.
I had an '02 CL500 several years ago which had 1 battery. It was located on the right side where the aux bat is now. But it had very easy access and could be swapped out in a few quick minutes.
Now while the aux is hard to get to, the starter bat is all the way in the front of the trunk. This requires climbing into the trunk and a strong back to remove it.
Luckily I had MB replace the starter battery on my CPO '16 coupe when I bought it but I didn't know it had the 2nd bat. And of course they didn't mention it. Anyway, I replaced it a few months ago since it was the orig and 5 years old.
I had an '02 CL500 several years ago which had 1 battery. It was located on the right side where the aux bat is now. But it had very easy access and could be swapped out in a few quick minutes.
Now while the aux is hard to get to, the starter bat is all the way in the front of the trunk. This requires climbing into the trunk and a strong back to remove it.
Luckily I had MB replace the starter battery on my CPO '16 coupe when I bought it but I didn't know it had the 2nd bat. And of course they didn't mention it. Anyway, I replaced it a few months ago since it was the orig and 5 years old.
Member
Joined: Dec 2020
Posts: 159
Likes: 91
From: NORTHERN NJ
2018 S560 4matic Sedan. Official member of the 18" RIM CREW.
This happened on my prior W222, an '18 S450, in the middle of the pandemic. When I called my service advisor, before I could even get out what the error message was he said "Let me guess, Aux Battery Malfunction"? He said he saw a ton of those and speculated that everyone's reduced driving caused it.
