How Do I Fix My Mercedes Auxiliary Battery Malfunction? Apr 2026

To fix a "Auxiliary Battery Malfunction" on your Mercedes-Benz, you generally need to replace the small auxiliary battery (or voltage converter) that supports secondary systems like the ECO start-stop, GPS, and safety sensors . Quick Diagnostic Steps

: Use an OBD-II scanner to look for battery-specific codes like B15DC00 or B142E . Common Locations by Model How Do I Fix My Mercedes Auxiliary Battery Malfunction?

The location varies significantly by model, so check your Owner's Manual first: Fix Auxiliary Battery Malfunction Mercedes-Benz E 350 To fix a "Auxiliary Battery Malfunction" on your