Here is a flowchart to resolve your issue without paying a cent initially:
Perform Method 2 (Fuse Pull).
Check your 12V battery (free test at any parts store). mercedesbenz errorb1fbd54 free
You have a hardware issue (backup battery or HERMES unit). The free methods have exhausted their potential.
First, let’s demystify the code. In Mercedes-Benz’s proprietary diagnostic language, B1FBD54 refers to a communication failure within the HERMES module (the car’s emergency call and telematics unit). Here is a flowchart to resolve your issue
In plain English: Your car’s built-in 4G/LTE modem, GPS antenna, and backup battery for the SOS system have stopped talking to the central computer. As a result, the dashboard lights up like a Christmas tree, and you lose automatic emergency calling (eCall), Mercedes me connect services, and often the overhead control panel lights.
While a professional scanner costs money, you may be able to clear the code for free using: Perform Method 2 (Fuse Pull)
Warning: Clearing the code without fixing the root cause will only make the light return. Always perform the connector reset first.