1 - driver's airbag
2 - front passenger airbag
3 - side airbag
Front airbags are designed to deploy when a frontal impact is of a certain force.
The front passenger airbag will only deploy when there is a passenger in the seat and the indicator light is on
on the center console does not flash or light up.
In the event of a minor accident, the front airbags do not deploy. The driver and passenger are protected by seat belts.
Warning! Do not place heavy objects on the front seat, as in the event of an accident the front passenger seat belt tensioner, front and side airbags will deploy.
Publication taken from an online resource mercedesman
Side airbags are deployed in the event of a side impact of a certain force and only on the side of the impact. The front passenger side airbag is deployed only if there is a passenger in the front seat at the time of the impact.