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Date of printing:
11/23/2009Interactive Owner's Manual [In depth | Occupant safety]
Owner's Manual version: ÄJ 2009/1 b
Note: The online Owner's Manual is the latest version available. Deviations between this manual and items specific to your vehicle may occur since Mercedes-Benz constantly adapts its vehicles to the latest technology and modifies design and equipment. Please note that this online Owner's Manual does not under any circumstances replace the printed Owner's Manual which is supplied with the vehicle.
Seat belts, together with belt tensioners, belt force limiters and airbags, are complementary, coordinated restraint systems. They reduce the risk of injury in specific, pre-defined types of accident situations and, thereby, increase occupant safety. However, seat belts and airbags generally do not protect against objects penetrating the vehicle from the outside.
To ensure that the restraint systems can deliver their full potential protection, you should ensure that:
the seat and head restraint are adjusted properly more.
the seat belt has been fastened properly more.
the airbags can inflate properly if they are deployed more.
the steering wheel is adjusted properly more.
The SRS reduces the risk of occupants coming into contact with the vehicle's interior in the event of an accident. It can also reduce the forces to which occupants are subjected during an accident.
The SRS consists of:
warning lamp
SRS functions are checked regularly when you turn on the ignition and when the engine is running. Therefore, malfunctions can be detected in good time.
The
warning
lamp in the instrument cluster lights up when the ignition is switched on. It
goes out no later than a few seconds after the engine is started.
In the event of a collision, the sensor in the airbag control unit evaluates important physical data such as duration, direction and force of the vehicle deceleration or acceleration. Based on the evaluation of this data and depending on the vehicle's rate of longitudinal deceleration in a collision, in the first stage the airbag control unit pre-emptively triggers the belt tensioners.
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The front belt tensioners can only be triggered if the belt tongue is correctly engaged in the seat belt buckle. |
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The front airbags are only deployed if there is an even higher rate of vehicle deceleration in a longitudinal direction.
Your vehicle has adaptive, dual stage front airbags. When the first activation threshold is reached, the front airbag is filled with enough propellant gas to reduce the risk of injuries. The front airbag is only fully inflated if a second threshold is reached within a few milliseconds, due to the control unit having detected further deceleration.
In the first stage of a collision, the airbag control unit evaluates the duration and direction of vehicle acceleration or deceleration in order to determine whether it is necessary to trigger the belt tensioner and/or airbag.
The belt tensioner and airbag triggering thresholds are variable and are adapted to the rate of deceleration of the vehicle. This process is pre-emptive in nature as the airbag must be deployed during - and not at the end of - the collision.
The rate of vehicle deceleration or acceleration and the direction of the force are basically determined by:
Factors which can only be seen and measured after a collision has occurred do not play a decisive role in the deployment of an airbag, nor do they provide an indication of it.
The vehicle may be deformed significantly, e. g. on the bonnet or the wing, without an airbag being deployed. This is the case if only parts which are relatively easily deformed are affected and the necessary deceleration does not occur. Conversely, airbags may be deployed even though the vehicle suffers only minor deformations. For example, this is the case if very rigid vehicle parts such as longitudinal body members are affected and sufficient deceleration occurs as a result.
The seat belts are fitted with belt tensioners.
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Do not engage the seat belt tongue in the buckle on the front-passenger seat if the seat is not occupied. The belt tensioners could otherwise be triggered in an accident. |
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If the seat belt is also equipped with a belt force limiter, the force exerted by the seat belt on the seat occupant is reduced.
Belt tensioners tighten the seat belts in an accident, pulling them close against the body.
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Belt tensioners do not correct incorrect seat positions or incorrectly fastened seat belts. Belt tensioners do not pull occupants back towards the backrest. |
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The front belt force limiters are synchronised with the front airbags, which distribute a proportion of the deceleration forces exerted on the occupant over a greater area.
The belt tensioners cannot be triggered when the ignition is switched on unless:
the restraint
systems are operational; see the
warning
lamp.
the belt tongue is engaged in the buckle on each lap-shoulder belt in the front of the vehicle.
Depending on the type and severity of an accident, the belt tensioners may be triggered:
in the event of a head-on or rear-end collision if the vehicle decelerates or accelerates rapidly in a longitudinal direction during the initial stages of impact
in the event of a side impact if the vehicle is subjected to high lateral acceleration/deceleration
If the airbags are deployed, you will hear a bang and a small
amount of powder may also be released. Only in rare cases will the bang affect
your hearing. The powder that escapes does not generally constitute a health
hazard. The
warning lamp lights up.
Airbag deployment slows down and restricts the movement of the vehicle occupant.
If the airbags are deployed, you will hear a bang and a small
amount of powder may also be released. Only in rare cases will the bang affect
your hearing. The powder that escapes does not generally constitute a health
hazard. The
warning lamp lights up.
The SRS/AIRBAG identification indicates the location of the airbags.
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Risk of injury |
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The airbag's functionality can only be guaranteed if the following parts are not covered and no badges or stickers are attached to them: |
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The front airbags are designed to increase protection for the driver's and front passenger's head and chest.
Driver's front
airbag
deploys in front of the steering wheel; front-passenger front airbag
deploys in
front of and above the glove compartment. They are deployed:
at the start of an accident with a high rate of vehicle acceleration or deceleration in a longitudinal direction
if the system determines that airbag deployment can offer additional protection to that provided by the seat belt
if the vehicle overturns, but only if the system detects high vehicle deceleration in a longitudinal direction
On vehicles with automatic child seat recognition in the
front-passenger seat*,
front-passenger front airbag
is only
deployed if the
PASSENGER AIRBAG OFF warning lamp in the centre
console is not lit
more. This means that a child restraint system with automatic
child seat recognition* has
not been fitted to the front-passenger seat or has been fitted incorrectly.
The purpose of sidebag deployment is to enhance the level of protection for the thorax (but not the head, neck or arms) of the vehicle occupants on the side of the vehicle on which the impact occurs.
Front sidebags
deploy in
the area of the front door. Rear-compartment sidebags*
inflate in
the area of the rear side wall beneath the respective side window. They are
deployed:
at the start of an accident with a high rate of lateral vehicle deceleration or acceleration, e.g. in a side impact
The purpose of the windowbags is to enhance the level of protection for the head (but not chest or arms) of the vehicle occupants on the side of the vehicle on which the impact occurs.
The windowbags are integrated into the side of the roof frame and run from the front door (A-pillar) to the rear side wall (C-pillar).
Windowbags are deployed:
If a child is travelling in your vehicle, secure the child using a child restraint system which is appropriate to the size and age of the child and is recommended for Mercedes-Benz vehicles. You should fit the restraint system to a suitable rear seat. Ensure that the child is secured throughout the trip.
You can obtain information about the correct child restraint system from any Mercedes-Benz Service Centre.
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It is advisable to use Mercedes-Benz care products to clean child restraint systems. Information about this can be obtained from any Mercedes-Benz Service Centre. |
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Mercedes-Benz recommends that you only use the child restraint systems listed at more.

Warning on the front-passenger sun visor

Warning symbol for a rearward-facing child restraint system
If your vehicle does not have automatic child seat recognition on the front-passenger seat, this is indicated by a special sticker. The sticker is affixed to the side of the dashboard on the front-passenger side. It is visible when you open the front-passenger door.
( Vehicles without automatic child seat recognition in the front-passenger seat: the warning lamp lights up briefly when you turn the key to position 2 in the ignition lock. However, it has no function and does not indicate that there is automatic child seat recognition on the front-passenger seat.)
is located on the centre console.
The sensors for the
automatic child seat recognition on the front-passenger seat detects whether a
special Mercedes-Benz child seat with automatic child seat recognition has been
fitted. In such cases,
PASSENGER
AIRBAG OFF warning lamp
lights up.
The front-passenger front airbag is disabled.
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(Move the front-passenger seat to its rearmost position.) or as recommended |
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Child restraint system on the left-hand and right-hand rear seats |
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Example of an approval label on the child restraint system
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(For child restraint systems without automatic child seat recognition, move the front-passenger seat to the rearmost position.) |
ISOFIX is a standardised securing system for specially-designed child restraint systems on the rear seats. Securing rings for two child restraint systems are fitted on the left and right rear seats.
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Securing rings |
Date of printing:
11/23/2009Interactive Owner's Manual [In depth | Occupant safety]
Owner's Manual version: ÄJ 2009/1 b
Note: The online Owner's Manual is the latest version available. Deviations between this manual and items specific to your vehicle may occur since Mercedes-Benz constantly adapts its vehicles to the latest technology and modifies design and equipment. Please note that this online Owner's Manual does not under any circumstances replace the printed Owner's Manual which is supplied with the vehicle.