Mercedes-Benz GL-Class: Safety notes - Operating safety - Introduction - Mercedes-Benz GL-Class Owner's ManualMercedes-Benz GL-Class: Safety notes

WARNING Work improperly carried out on electronic 
Work improperly carried out on electronic components and associated software could cause them to cease functioning. Because the vehicle's electronic components are interconnected, any modifications made may produce an undesired effect on other systems. Electronic malfunctions could seriously impair the operating safety of your vehicle.
Contact an authorized Mercedes-Benz Center for repairs or modifications to electronic components.
Other improper work or modifications on the vehicle could also have a negative impact on the operating safety of the vehicle.
Some safety systems only function when the engine is running. You should therefore never turn off the engine while driving.

WARNING Heavy blows against the vehicle underbody or 
Heavy blows against the vehicle underbody or tires/wheels may cause serious damage and impair the operating safety of your vehicle.
Such blows can be caused, for example, by running over an obstacle, road debris or a pothole.
If you feel a sudden significant vibration or ride disturbance, or you suspect that damage to your vehicle has occurred:
turn on your hazard warning flashers.
slow down carefully.
drive with caution to an area which is a safe distance from the road.
Inspect the vehicle underbody and tires/ wheels for possible damage. If the vehicle appears unsafe, have it towed to the nearest authorized Mercedes-Benz Center or other qualified maintenance or repair facility for further inspection or repairs.

    Qualified specialist workshop
    An authorized Mercedes-Benz Center is a qualified specialist workshop. It has the necessary specialist knowledge, tools and qualifications to correctly carry out the work required on your vehicle. ...

    See also:

    Off-road drive program
    The off-road drive program is available only in vehicles without the Off-Road Pro engineering package. The off-road drive program assists you in driving off-road. The engine’s performance ch ...

    Deselecting valet mode
    When you enter the vehicle, touch the Valet button to view the Valet mode screen. Enter your 4 digit PIN and touch the OK button. Valet mode deactivated is displayed to indicate that your PIN has ...

    Air quality sensor
    Press once to activate air recirculation. Press again to activate automatic air recirculation. In automatic mode, air recirculation is regulated to achieve optimum air conditioning performance. ...