SL/R231: auxiliary battery malfunction/convenience feature not working
Thread Starter
MBWorld Fanatic!
Joined: Feb 2004
Posts: 3,122
Likes: 222
From: Milton/Westport, MA USA
me: 2015 SL400 & 2015 ML400; wife: 2022 GLC Coupe; daughter: 2017 GLC SUV
auxiliary battery malfunction/convenience feature not working
I've combined topics as I believe they may be related. Like many, I assume, I haven't been driving much for the last 8 months. Lately I've been getting alerts about Service B9 being due soon (as an aside, my service advisor says it's a 50k mile service that will run around $835.42 for air filter sparkplugs and oil change; I've got fewer than 45,000 miles and got the 40K service in December 2019). Anyway, the Service B9 alert may have obscured the auxiliary battery malfunction alert, but I've started to see that, and it seems to be coinciding with my seat and steering wheel not moving for easy exit when I turn off the car.
Thoughts?
Thoughts?
Super Member
Joined: Jul 2018
Posts: 563
Likes: 171
From: Nothern Georgia, U.S.A.
'17 SL450, '25 Lyriq, '25 Sonata Hybrid, '96 Corvette GS coupe
The original auxiliary battery in my '17 SL was made by Fiamm. It looks like a conventional motorcycle battery, but it is an AGM battery and has the terminals and vent pipe in semi-specific orientations, so I don't know if you could source a suitable substitute for the M-B replacement or not. Most here have been buying them from their dealers. There are a few other threads on here that have a lot of information about this subject...
https://mbworld.org/forums/sl-class-...tery-type.html
or
https://mbworld.org/forums/sl-class-...ent-guide.html
or even
https://mbworld.org/forums/sl-class-...y-battery.html
https://mbworld.org/forums/sl-class-...tery-type.html
or
https://mbworld.org/forums/sl-class-...ent-guide.html
or even
https://mbworld.org/forums/sl-class-...y-battery.html
Last edited by Dr. Manhattan; Dec 2, 2020 at 02:37 AM.
Senior Member
Joined: Jan 2019
Posts: 475
Likes: 157
From: Philadelphia area
2014 SL65 AMG, 2018 S560
I've combined topics as I believe they may be related. Like many, I assume, I haven't been driving much for the last 8 months. Lately I've been getting alerts about Service B9 being due soon (as an aside, my service advisor says it's a 50k mile service that will run around $835.42 for air filter sparkplugs and oil change; I've got fewer than 45,000 miles and got the 40K service in December 2019). Anyway, the Service B9 alert may have obscured the auxiliary battery malfunction alert, but I've started to see that, and it seems to be coinciding with my seat and steering wheel not moving for easy exit when I turn off the car.
Thoughts?
Thoughts?
