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So after startup this morning, I received an "auxiliary battery malfunction" message on the display. This battery is located behind the driver side fuse panel, just above the hood release. You need to remove the plastic panel under the driver side dash and the half-circular panel behind the driver's door to access.
The battery is relatively easy to access once you know where it is (lots of misinformation out there...it's not behind the rear seat or in the engine compartment on a 2011). FYI, the battery part number is N000000004039.
My only question is do I need to do anything special when I change it? The main starting battery is good. I'm curious if there are any ill effects from disconnecting it and installing the new one (i.e. memory loss). From what I've read, this battery is a backup for the electronic shift mechanism. Does this mean it just allows you to shift into neutral, etc. if the main battery is dead (to push or tow a non starting car)? Does anyone know if this battery serves another function?
Last edited by Rickalders; 06-17-2016 at 10:44 PM.
I didn't even know it had a battery there. The primary starting battery is in the engine compartment and my understanding was the secondary (aux) battery was behind the false wall in the trunk. Are you sure the error message is referencing that little guy under the dash and not the huge battery in the trunk?
Edit: if you're sure it's that one, there shouldn't be any issues with losing memory since all of the SAMs get power from the secondary battery in the trunk, along with the ME and other drivetrain related computers.
I didn't even know it had a battery there. The primary starting battery is in the engine compartment and my understanding was the secondary (aux) battery was behind the false wall in the trunk. Are you sure the error message is referencing that little guy under the dash and not the huge battery in the trunk?
Edit: if you're sure it's that one, there shouldn't be any issues with losing memory since all of the SAMs get power from the secondary battery in the trunk, along with the ME and other drivetrain related computers.
2010 and above have main battery and under the dash, the small auxiliary battery.
2009 and earlier have the main battery and located behind the panel in the trunk, the full sized auxiliary battery
Just had mine changed from the dealership not too long ago. Wasn't too expensive. Had the same error message. Distrionic Plus and the hold function did not work till I swapped it out.
2010 and above have main battery and under the dash, the small auxiliary battery.
2009 and earlier have the main battery and located behind the panel in the trunk, the full sized auxiliary battery
I have a 2009 and just found out that my AUX battery is under the dash (yes I looked in the trunk first, where there's a nice empty space)
The looked under the dash and found the small AUX battery there
So it seems to me that MB started to make this change on some late pre-facelift models.
I have a 2011 S63. I went to change my aux battery and it wasn't under the dash as others or you have described. The bracket to hold it in place is there. But there aren't even terminals to plug a battery in. Is the placement of this battery different on the S63 AMG models? Does anyone know this?
I think this battery only serves extra functions such as powering the sensors for safety equipment like the distronic cruise control and etc. When I got the aux battery alarm, I also started getting the alarm DISTRONIC PLUS INACTIVE when I tried engaging it.
My 2011 S63 doesn't have the aux battery under the dash. I haven't had time to check the trunk yet. I'm hoping it's in there and I have the right one...
I’ve seen in all videos for this year make and model that the location of the aux battery is behind the fuse box. You’ll need a T25 torx and a 10mm socket. You can drive your car normally with this alarm. You just won’t have use of your cruise control and one or more of the granny’s such as lane departure assist or blind side sensors. It’s very easy to get to and change out.
Trouble for me is that nobody with an AMG model has posted a video and when I went to change mine, I assumed it was in the same spot. It is not. So I’m on the hunt for my aux battery. Can’t find anything in the manual or on line. I ordered an actual repair manual that techs use to do repair work on my model and will have the answer to my question soon. Hope the info above helps you.
Good afternoon pal,
I also have a 2011 S63 AMG and I'm also looking for the Auxiliary battery.
It definitely is not under dash in driver's side as in regular S550.
Did you have any luck finding it?
Many thanks.
Purpose of aux battery is to provide power to gear shift solenoid ... so you can get it out of park with a dead main battery. If they’re both dead, call your dealer and they will come out with special equipment to attach to a wheel so you can at least get your car out of the garage.
2011 S63 , 1997 SL500 La costa edition (sold) 1987 560SEC (sold)
Originally Posted by lkchris
Purpose of aux battery is to provide power to gear shift solenoid ... so you can get it out of park with a dead main battery. If they’re both dead, call your dealer and they will come out with special equipment to attach to a wheel so you can at least get your car out of the garage.
Why call the dealer when I can just jump the main battery and get it started?
06-17-2016, 10:29 PM
Changing Auxiliary Battery 2011 S550
