Lpoujol

I took my ML320 2008 CDI to my European Car shop to replace the Auxiliary Battery. We tried mine first, that I got at Batteries Plus, and after not being able to get rid of the malfunction error, we tried theirs from the dealership. After 2 hours, the error message persists: " Auxiliary Battery Malfunction". The original message before changing the old Aux Battery said "Auxiliary Battery Inoperative". We're baffled. Any ideas will be welcomed.

Plutoe

Your European car shop does not know what they are doing----find someone with the diagnostics and clear the fault---then go have a lamb dinner!

stemags

Wtg Key,,that's the aux,,like I said,,like a mcy battery,,and same size as my grandson electric jeep.👌🍺.Thanks again to all.