This phrase refers to a specific, older generation of diagnostic interface and software for Mercedes-Benz vehicles. The report clarifies what it is, its capabilities, limitations, and practical advice for potential users.

Step 2: Install FTDI Drivers First

• Do NOT plug in the USB cable yet.
• Run CDM20828_Setup.exe (or latest FTDI virtual COM port driver).
• After installation, connect the USB cable. Windows should detect "USB Serial Port (COMx)". Note the COM port number.

• K-Line (Pin 7): Diagnostic data streaming.
• L-Line (Pin 15): Initialization of the control unit.

• Low cost compared with dealer tools.
• Portable and laptop‑based—flexible for field work.
• Covers a wide range of common diagnostic tasks.