"No signal change" (Изменение сигнала отсутствует), meaning the car's computer (often the Front SAM or COMAND/MBUX module) recognizes the button is physically depressed or electronically shorted and is no longer responding to new presses. Common Causes & Solutions
The diagnostic trouble code (DTC) specifically refers to a mechanical or electrical failure of the "Favorites" button (often identified as the button with a star icon) on the center console or steering wheel control bank.
If you are seeing this code in a diagnostic report, consider the following steps: Physical Inspection
: If the button feels physically fine, use an OBD-II scanner to clear the code. If it returns immediately, the internal switch behind the button may be faulty and require replacement of that specific control panel. how to access the control panel for a specific Mercedes-Benz model to clean it?