Why does the Mercedes-Benz auto start-stop always show a yellow light?

[Costa]

If the auto start-stop system in a Mercedes-Benz always displays a yellow light, it indicates that the battery is low on charge and needs to be recharged. Here is a detailed introduction to the auto start-stop function: Auto Start-Stop Button: The auto start-stop button is located to the left of the cigarette lighter, featuring an icon of a circle with the letter 'A' inside and the word 'OFF' below. Simply press the button once to deactivate the auto start-stop. Default Setting: The auto start-stop function is enabled by default. Each time the vehicle is restarted, the auto start-stop will turn on again. This button cannot permanently disable the function; you need to press it every time you start the vehicle to turn it off. Function: The engine auto start-stop system automatically shuts off the engine when the vehicle comes to a temporary stop (e.g., at a red light). When it's time to move again, the system automatically restarts the engine. This helps reduce unnecessary fuel consumption, lower emissions, and improve fuel economy.