(Problem with my uncles car, he posted this to Facebook too)
Hi, I have an issue with my c300de 2020 W205. i drove it to the shop normal then got back in, attempted to start the car and it cranked then instantly shut off with a Malfunction light with exclamation mark in middle of the battery, see photos attached.
I hooked up my diagnostic tool and it is showing 3 Fault codes, P0B4600, POA9500 and POABB00 returned each time, the squib pyrofuse, the SRS and BMS. i believe the car thinks it has had a crash and registered crash data but we have tried clearing the SRS crash data 1st then reset BMS but that was AA And RAC and I'm not sure if their diagnostic tablets are capable of deleting crash data or not.
It’s now with a Mercedes garage and they still not sure what is wrong they have emailed technical head office in Germany for advice, has anyone come across this issue on this site that can help I'm £2000 deep into attempted fixes just jumping from garage to garage charging a small fortune ATM.
Update:
Mercedes have come back to me and said it all points to a new 48v Hybrid battery but that is very expensive and when I did my own battery test with my Topdon ArtiDiag 900 lite it was showing the battery in good health and the relays were open but if the SRS data was deleted and then reset BMS should that not then allow the relays to close and talk to the ecu again.