Why can't the Mercedes HOLD function be activated?

The Mercedes HOLD function not activating is due to incorrect method. The correct operation is: after the vehicle comes to a complete stop, quickly press the brake once; the brake doesn't need to be pressed deeply, but it must be done quickly. Once familiar, activating HOLD will come naturally. The Mercedes HOLD function is similar to automatic parking.

The Mercedes HOLD function has prerequisites. It is analogous to AUTOHOLD (automatic parking). Most models' automatic parking only operates properly when the seatbelt is fastened and the doors are closed. Some vehicles allow the automatic parking function to be turned off via a button. By default, it is enabled and needs to be manually turned off every time the vehicle is started. However, the Mercedes HOLD cannot be turned off.

Prerequisites for activating the Mercedes HOLD function:

• The vehicle is stationary;
• The engine is running or has been automatically shut off by ECO (start/stop function);
• The electric parking brake is released;
• The transmission is in D, N, or R gear.