Does the Aux battery malfunction message needed MB to clear it?
Thread Starter
Newbie
Joined: Mar 2021
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2015 C250 estate
Does the Aux battery malfunction message needed MB to clear it?
I have had the aux battery failure, and replaced it myself, however I still have the white failure message coming up. I have in the past had the red message too. All stop start functions are working, I just have the annoying message which keeps popping up every 5 or 10 seconds. Does the error code need to be cleared using Xentry, by MB?
Thread Starter
Newbie
Joined: Mar 2021
Posts: 5
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2015 C250 estate
Thanks Greg , was your nag warning only white? I had heard others say this but wondered if the fact that mine went to a red warning that might have been flagged as more serious and need resetting.
Member
Joined: Jan 2017
Posts: 96
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From: Sydney
W205 C250
it was several years ago but my memory was that it started off white and after a week or so went to red , do you push the ok button on the steering wheel to cancel it?
Member
Joined: Jan 2017
Posts: 96
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From: Sydney
W205 C250
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Member
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From: Sydney
W205 C250
Junior Member
Joined: Oct 2014
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From: Glasgow,Scotland
2014 220 AMG
I was advised that the main function of the auxiliary battery was to facilitate the Stop/Start function but before I replaced it I had to buy a main battery and immediately the Stop/Start function sprang into life and has worked faultlessly ever since. The auxiliary battery malfunction message still flashes every few seconds despite having had a scanner try to clear the code. I then fitted a new replacement but no luck, the message still persists, to my great annoyance. As all functions in my W205 C Class are working I am tempted to learn to live with the irritating message flashing constantly. Unless someone can tell me what else I can do to solve this issue.
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Joined: May 2018
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W205 2015
I was advised that the main function of the auxiliary battery was to facilitate the Stop/Start function but before I replaced it I had to buy a main battery and immediately the Stop/Start function sprang into life and has worked faultlessly ever since. The auxiliary battery malfunction message still flashes every few seconds despite having had a scanner try to clear the code. I then fitted a new replacement but no luck, the message still persists, to my great annoyance. As all functions in my W205 C Class are working I am tempted to learn to live with the irritating message flashing constantly. Unless someone can tell me what else I can do to solve this issue.
Member
Joined: Jan 2017
Posts: 96
Likes: 17
From: Sydney
W205 C250
I was advised that the main function of the auxiliary battery was to facilitate the Stop/Start function but before I replaced it I had to buy a main battery and immediately the Stop/Start function sprang into life and has worked faultlessly ever since. The auxiliary battery malfunction message still flashes every few seconds despite having had a scanner try to clear the code. I then fitted a new replacement but no luck, the message still persists, to my great annoyance. As all functions in my W205 C Class are working I am tempted to learn to live with the irritating message flashing constantly. Unless someone can tell me what else I can do to solve this issue.
I think your problem is somewhat unique and I doubt anyone here would be able to assist. Shame you couldn’t get a warranty on the original repair, I understand a reluctance to visit the dealership but other than putting up with the error message this may be your only avenue, good luck
Junior Member
Joined: Apr 2018
Posts: 52
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2018 C 300
I have had the aux battery failure, and replaced it myself, however I still have the white failure message coming up. I have in the past had the red message too. All stop start functions are working, I just have the annoying message which keeps popping up every 5 or 10 seconds. Does the error code need to be cleared using Xentry, by MB?
MBWorld Fanatic!
Joined: Oct 2018
Posts: 1,430
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From: Florida
2018 AMG E43
I had my Auxiliary Battery replaced under warranty and had no further issues. I'd assume there is something else amiss if you are still getting active codes. Does your main battery load test check-out okay?
Good luck!
Junior Member
Joined: Apr 2018
Posts: 52
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2018 C 300
I'm not sure exactly what your issue is, but I know it's a safe bet that if you clear a fault code and it comes back as a new active fault, the issue is not resolved.
I had my Auxiliary Battery replaced under warranty and had no further issues. I'd assume there is something else amiss if you are still getting active codes. Does your main battery load test check-out okay?
Good luck!
I had my Auxiliary Battery replaced under warranty and had no further issues. I'd assume there is something else amiss if you are still getting active codes. Does your main battery load test check-out okay?
Good luck!
Junior Member
Joined: Apr 2018
Posts: 52
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2018 C 300
I put a new main battery in about 6 months ago and load tested it and was ok. I was watching a video about the auxiliary battery and they also mentioned something about a fuse under the rear trunk and when I pulled it out it looked pretty dark/burned. I will pick one up tomorrow and hoping that will solve the issue.
Member
Joined: Jan 2017
Posts: 96
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From: Sydney
W205 C250
Turns out the fuse solved the problem. As soon as I put the new fuse in and started up the car the warning message was gone. If anyone runs into this problem where the "Auxiliary Battery Malfunction" warning message does not go away even after replacing the part, check fuse number 448 located in the trunk under the cargo floor to see if it needs to be replaced.
Junior Member
Joined: Oct 2014
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From: Glasgow,Scotland
2014 220 AMG
Hi,
I took my vehicle to a MB independent specialist who was able to clear the fault message, unfortunately I cannot recall the cost but confident it was much less expensive than the main stealer.
I took my vehicle to a MB independent specialist who was able to clear the fault message, unfortunately I cannot recall the cost but confident it was much less expensive than the main stealer.
