Mercedes-Benz Intelligent Drive

PRE-SAFE® system

In critical situations the system activates preventive measures to protect the occupants in case of an accident, e.g. belt tensioning, closing of windows and roof and positioning of the front passenger's seat.

Preventive occupant protection.

More detailed information


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The multiple award-winning PRE-SAFE® system is able to activate precautionary occupant protection measures in critical driving situations.


This is possible by virtue of the fact that the system is linked up to the Brake Assist system (BAS) and the Electronic Stability Program (ESP®), whose sensors identify driving situations approaching the critical limits of road holding and relay corresponding information to the electronic control units in a matter of milliseconds. These sensor data are also used by the PRE-SAFE® system.


Depending on the model and equipment line concerned, the PRE-SAFE® system comprises reversible belt tensioners, adaptive belt force limiters, PRE-SAFE® positioning function for the front passenger's seat, automatic closing of the side windows and tilting/sliding roof or the full-glass top sliding roof.


Mercedes-Benz accident research shows that in two thirds of all accidents sufficient time remains to initiate precautionary protection measures before actual impact. If a crash does occur, vehicle and passengers are better prepared with the PRE-SAFE® system. If the accident is avoided, the fully reversible systems can be returned to their original positions and are then immediately ready for use again.
The driver's and front passenger's seat belts can be tensioned as a preventive measure by means of the reversible belt tensioners, for example. This precautionary measure ensures that driver and front passenger are fixed in their seats as effectively as possible and will not shift so far forward in the event of impact, reducing the strain on the head (approx. -30%) and neck (approx. -40%), as crash test analyses have shown.


The front passenger's seat and individual rear seats can be adjusted into a position offering better protection in the event of a collision. In addition, the chambers in the side bolsters on the various multicontour seats can be filled with air. This improves lateral support for the occupants and helps to maintain the space between seat and sidewall in critical driving situations. This, in turn, increases the effectiveness of the side airbags in protecting the occupants.
If the sensors detect over- or understeering, indicating that the vehicle has left the road and that there is a danger of it overturning, the side windows and sliding roof can additionally close automatically.


The vehicle sensing system of the optional DISTRONIC PLUS package is also used to detect a vehicle ahead and any danger of a rear-end collision.



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