Here is the tutorial on repairing the Mercedes Benz 48 volt mild hybrid battery.
01: 48V Battery Benefits
By using a 48-volt electrical system in new Mercedes-Benz vehicles, the car can be powered solely on the electrical system battery instead of using the drivetrain batteries. In fact, these drivetrain batteries can be removed altogether, making the vehicle safer overall because there aren’t dangerous amounts of electricity traveling through the car.
02: Device to repair
03: Model affected
2015 onwards Mercedes Benz W167 W205 W213 W222 etc
Battery Malfunction, limits the output, car fails to start
1. Instrument cluster message 48 V on-board electrical system battery (G1/3) in yellow or red
2. Vehicle does not start
05: Common Fault Codes
B183349: There is an internal electrical fault.
B183371: Actuator is locked
B183384: There is a signal below the allowed limit
B183319: The battery for 48V on-board electrical system has a malfunction. The actuator is blocked.
Collision accidents, battery drain, electrical short circuit etc., will cause the chip data on the battery management system (BMS) to be locked.
Replace the battery or modify chip data, then charge the battery to standard voltage
check and confirm the vehicle is equipped with M256 or M264 engine computer.
Different engines have different data modification approaches.
09: Repair Guide
Remove and disassemble the battery
Locate IC chip 95M01
You can see the IC chip when you open the upper case of the battery. This chip controls the operation of the entire battery.
In CG100 software, select Programmer- 8 foot chip- 95M01
CG100 will show you the wiring diagram
Solder IC chip to BDM4 adapter and connect with CG100
Then read and save eeprom data.
Send the original data to CG engineer.
You will receive a modified bin file.
Write the new bin file to repair battery module.
Install battery back to the vehicle and charge it to standard voltage.
Check the previous guide How to repair Porsche Cayenne Lithium Battey with CG100
The difference is that CG100 comes with built-in write data for the Cayenne battery. At Mercedes, you need to send original data to CG engineer to obtain modified data.