Posting this experience because it might help others here: yesterday my 2019 W213/A238 was at my local dealership for some recall work (SRPC2409 - Sealing of transmission wiring harness connector). While undertaking the work the technician observed a code related to a fault on the MHEV 48 volt battery. There was no error message on the dashboard.
At first they quoted me £1,324 for replacement of the battery including labour and VAT. Soon after that quote however they told me that the fault could be rectified without replacing the battery but by simply performing a software update on the existing one. This was completed at the cost of 1.6 hours labour.
At first they quoted me £1,324 for replacement of the battery including labour and VAT. Soon after that quote however they told me that the fault could be rectified without replacing the battery but by simply performing a software update on the existing one. This was completed at the cost of 1.6 hours labour.
Windows 10 took less than that!!
I suspect that included the diagnostics time for hunting down,the solution.