Hello, just wanted to jump in as well. As BMDOUBLE stated earlier, the auxiliary battery should be in the luggage compartment. Mercedes gives a poor diagram as to the exact location but it looks like you will need to remove the trim covers to actually see it?
I would recommend you get an advance scan tool and do a full system scan to see what codes may be posted. Once you have those codes we can further assist. Also when I mention a scan, I do not mean those quick scans you get from the parts stores. You only get engine and maybe ABS codes. I am talking about a full scan where it scans every module in your vehicle.
Let us know if you find the auxiliary battery after removing all panels in trunk or if you can get the whole computer system scanned.
Monday, August 12th, 2019 AT 11:06 PM