Mercedes-Benz GL-Class: Adjusting the seats in the second andthird rows - Seats - Seats, steering wheel and mirrors - Mercedes-Benz GL-Class Owner's ManualMercedes-Benz GL-Class: Adjusting the seats in the second andthird rows

Important safety notes

WARNING Never travel in a moving vehicle with the seat 
Never travel in a moving vehicle with the seat backrest in an excessively reclined position as this can be dangerous. You could slide under the seat belt in a collision. If you slide under it, the seat belt would apply force at the abdomen or neck. This could cause serious or fatal injuries. The seat backrest and seat belt provide the best restraint when the wearer is in a position that is as upright as possible and the seat belt is properly positioned on the body.
Your seat belt must be adjusted so that you can correctly fasten your seat belt.
Never place hands under the seat or near any moving parts while a seat is being adjusted.
After adjusting the seat, always ensure that the seat and the backrest are correctly engaged. The backrest must be in an upright position.
Test the stability of the latch by pushing and pulling the backrest. If the seat and backrest are not correctly latched, the seat could move forward and the backrest could fold down.
While braking, changing direction, or in an accident, you could slide out from under the seat belt. The child seat would no longer be correctly supported or correctly positioned and would no longer carry out its intended function. This could cause serious or fatal injuries.

Adjusting the head restraint height(second and third row of seats)
Outer seat head restraints in the second row of seats Outer seat head restraints in the third row of seats ► If the head restraint is fully lowered, it is necessary to press release ...

Adjusting the backrest angle (2nd rowof seats)
WARNING   The seat belt only offers its intended protection when the seat backrest is in a nearly vertical position and the occupant is sitting upright. The seat backrest and seat belt ...

See also:

Emergency Tensioning Devices, beltforce limiters
The seat belts for the front seats are equipped with ETDs/belt buckle tensioners and seat belt force limiters. The outer seat belts in the second row of seats are equipped with ETDs and seat belt f ...

Torque Lock
If you are parking on a hill and you do not shift the transmission into P (Park) properly, the weight of the vehicle can put too much force on the parking pawl in the transmission. It might be diffi ...

Heated seats (if so equipped)
WARNING Do not use or allow occupants to use the seat heater if you or the occupants cannot monitor elevated seat temperatures or have an inability to feel pain in body parts that contact t ...