SLK - Interactive Owner's Manual [In depth | Safety

Occupant safety

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Seat belts, together with belt tensioners, belt force limiters and airbags, are coordinated restraint systems. They reduce the risk of injury in defined 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 restraint systems have not been modified

An airbag increases the protection of vehicle occupants wearing a seat belt. However, airbags are only an additional restraint system which complements, but does not replace, the seat belt. All vehicle occupants must wear their seat belt correctly at all times, even if the vehicle is equipped with airbags. This is because - on the one hand - airbags are not deployed in all types of accident, as in some situations airbag deployment would not increase the protection afforded to vehicle occupants, provided they are wearing their seat belt correctly. On the other hand, airbag deployment only provides increased protection if the seat belt is worn correctly because:

the seat belt helps to keep the vehicle occupant in the best position in relation to the airbag
for example, in a head-on collision, the seat belt can more adequately prevent the occupant from being propelled towards the force of the impact, and is thus better suited to prevent injury

Therefore, in accident situations where an airbag is deployed, it only provides protection in addition to the seat belt if the seat belt is being worn correctly.

Risk of injury

The restraint system may not work as intended if the following components have been modified or work on these components has not been performed correctly:

restraint system, consisting of the seat belts and anchorages, belt tensioners, belt force limiters, airbags
wiring
networked electronic systems

Airbags or belt tensioners could then fail, e.g. in the event of an accident in which the deceleration force would normally be high enough to trigger the systems, or they could be triggered unintentionally. Never carry out any modifications on the restraint systems. Never tamper with electronic components and their software.

Risk of accident and injury

Always have maintenance work carried out at a qualified specialist workshop which has the necessary specialist knowledge and tools to carry out the work required.

Mercedes-Benz recommends that you use a Mercedes-Benz Service Centre for this purpose.

In particular, work relevant to safety or on safety-related systems must be carried out at a qualified specialist workshop. If this work is not carried out correctly, the operating safety of your vehicle may be affected. There is a risk of an accident and injury.

SRS (Supplemental Restraint System)

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 exposed during an accident.

The SRS consists of:

warning lamp
Belt tensioners
Belt force limiters
Airbags

warning lamp

The SRS functions are checked regularly when you turn on the ignition and when the engine is running. Malfunctions can therefore be detected in good time.

The resources/font_symbols/mbsymb1/mbsymb1_0031.png 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.

Risk of injury

If SRS is malfunctioning, individual systems may be activated unintentionally or not be triggered in the event of an accident with heavy braking.

A malfunction has occurred if the warning lamp:

does not light up when you switch on the ignition
does not go out after the engine has been running for a few seconds
lights up again once the engine is running

In this case, have SRS checked immediately at a qualified specialist workshop.

Triggering of belt tensioners, belt force limiters and airbags

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.


The belt tensioners can only be triggered if the belt tongue is correctly engaged in the seat belt buckle.

The front airbags are only deployed if there is an even higher rate of vehicle deceleration in a longitudinal direction.

Vehicles fitted with adaptive, dual-stage front airbags: when the first deployment threshold is reached, the front airbag is filled with enough 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.

Criteria for triggering belt tensioners and airbags

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.

Airbags are not deployed in all types of accidents. They are controlled by complex sensor technology and evaluation logic. This process is pre-emptive in nature as airbag deployment must take place during the impact and must be adapted to provide calculated, additional protection for the vehicle occupants. Not all airbags are deployed in an accident.

The different airbag systems work independently of each other. However, each individual system depends on the type of accident determined by the control system in the first stages of the collision (head-on collision, side impact, rear-end collision and overturn) and the extent of the accident (in particular, the vehicle's rate of deceleration or acceleration).

The rate of vehicle deceleration or acceleration and the direction of the force are basically determined by:

the distribution of forces during the collision
the collision angle
the deformation characteristics of the vehicle
the characteristics of the object with which the vehicle has collided, e.g. the other vehicle

Factors which can only be seen and measured after the collision has taken place 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 happens 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. This is the case if, for example, very rigid vehicle parts such as longitudinal body members are affected and sufficient deceleration occurs as a result.

Belt tensioners, belt force limiters

The seat belts are fitted with belt tensioners.


Do not engage the seat belt tongue in the buckle on the front-passenger seat if the seat is not occupied. Otherwise the belt tensioner could be activated in an emergency.

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.

Belt tensioners do not correct incorrect seat positions or incorrectly fastened seat belts.

Belt tensioners do not pull occupants back towards the backrest.

The belt force limiters are synchronised with the front airbags, which spread the forces exerted by the belt force limiters on the occupant over a greater area.

When the ignition is switched on, the belt tensioner is triggered:

only if the restraint systems are operational (the warning lamp lights up after the ignition is switched on and goes out once the engine is running)more
for each three-point seat belt in the front of the vehicle when the belt tongue is engaged in the buckle
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 the collision
In certain situations if the vehicle overturns, if the system determines that it can provide additional protection
on the front-passenger side only if the front-passenger seat is occupied and the belt tongue is engaged in the buckle

When the belt tensioners are triggered, you will hear a bang, which will not cause any harm to your hearing, and a small amount of powder may also be released. The resources/font_symbols/mbsymb1/mbsymb1_0031.png warning lamp lights up.

Risk of injury

If the seat belt tensioners have been triggered, they provide no additional protection in the event of another accident. Therefore, have belt tensioners which have been triggered replaced at a qualified specialist workshop.

Comply with safety regulations when disposing of belt tensioners. Any Mercedes-Benz Service Centre can provide details of these regulations.

Airbags

Airbag deployment slows down and restricts the movement of the vehicle occupant.

When the airbags are deployed, you will hear a bang, which will not cause any harm to your hearing, and a small amount of powder may also be released. The resources/font_symbols/mbsymb1/mbsymb1_0031.png warning lamp lights up.

The SRS/AIRBAG symbol indicates the location of the airbags.

Risk of injury

Airbags provide additional protection; they are not, however, a substitute for the seat belts.

Observe the following notes to reduce the risk of serious or even fatal injury if an airbag is deployed:

All vehicle occupants - in particular pregnant women - must wear their seat belt correctly at all times and lean back against the backrest, which should be positioned as close to the vertical as possible. The head restraint must support the back of the seat occupant's head at about eye level.
Always secure children less than 1.50 m tall or under 12 years of age in suitable child restraint systems.
All vehicle occupants must select a seat position that is as far away from the airbag as possible. The driver's seat position must allow the vehicle to be driven safely. The driver's chest should be as far away from the middle of the driver's front airbag cover as possible.
Move the front-passenger seat as far back as possible, in particular, if a child is secured in a child restraint system on the seat.
Vehicle occupants - in particular, children - must not lean their head on the area of the window from which a head/thorax airbag is deployed.
Rearward-facing child restraint systems must not be fitted to the front-passenger seat unless the front-passenger front airbag has been disabled. The front-passenger front airbag is disabled if a child restraint system with automatic child seat recognition is fitted to the front-passenger seat. The PASSENGER AIRBAG OFF warning lamp must be constantly lit.

If you secure a forward-facing child restraint system to the front-passenger seat, you must move the front-passenger seat as far back as possible.
Make sure there are no heavy or sharp-edged objects in pockets of clothing.
Do not lean forwards, e.g. over the cover of the driver's front airbag, particularly when the vehicle is in motion.
Do not put your feet on the dashboard.
Only hold the steering wheel by the rim. This allows the airbag to inflate fully. You could be injured if the airbag is deployed and you are holding the inside of the steering wheel.
Do not lean on the doors from inside the vehicle.
Make sure that there are no people, animals or objects between the vehicle occupants and the area of deployment of the airbag.
Do not place any objects between the seat backrest and the door.
Do not hang any hard objects, for example coat hangers, on the grab handles or coat hooks.
Do not attach accessories, e.g. cup holders, to the doors.

It is not possible to rule out the risk of injuries caused by an airbag due to the high speed at which the airbag is required to deploy.

Risk of injury

The airbag's functionality can only be guaranteed if the following parts are not covered and no badges or stickers are attached to them:

Padded steering wheel boss
Front-passenger front airbag cover
Outer side of seats

Risk of injury

When an airbag deploys, a small amount of powder is released. The powder may cause short-term breathing difficulties to persons suffering from asthma or other pulmonary conditions.

In order to prevent possible breathing difficulties you should leave the vehicle as soon as it is safe to do so. You can also open the window to allow fresh air to enter the interior. The powder does not constitute a health hazard and does not indicate that there is a fire in the vehicle.

Risk of injury

The airbag parts are hot after the airbag has been deployed. Do not touch them, otherwise you may burn yourself.

Occupants are not protected by the airbags in the event of another accident. Have the airbags checked at a qualified specialist workshop.

Front airbags

The front airbags are designed to increase protection for the driver's and front-passenger head and chest.

The driver's front airbag and front-passenger front airbag 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 seat belt is fastened
independently of other airbags in the vehicle
if the vehicle overturns, but only if the system detects high vehicle deceleration in a longitudinal direction

resources/font_symbols/mbsymb5/mbsymb5_0031.png

Driver's front airbag

resources/font_symbols/mbsymb5/mbsymb5_0032.png

Front-passenger front airbag

Driver's front airbag resources/font_symbols/mbsymb5/mbsymb5_0031.png deploys in front of the steering wheel; front-passenger front airbag deploys in front of and above the glove compartment.

Front-passenger front airbag resources/font_symbols/mbsymb5/mbsymb5_0032.png is only deployed if the front-passenger seat is occupied or if the resources/font_symbols/mbsymb1b/mbsymb1b_0035.png 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.


Do not place heavy objects on the front-passenger seat. The system might erroneously interpret this as a person occupying the seat and the restraint systems on the front-passenger seat may then be triggered in the event of an accident and would have to be replaced.

Head/thorax airbags

Risk of injury

If you wish to use seat covers, Mercedes-Benz recommends that, for safety reasons, you only use seat covers that have been approved for Mercedes-Benz vehicles. The seat covers must be equipped with a special tear seam for head/thorax airbags. Otherwise, a head/thorax airbag may not deploy correctly and could fail to provide the intended protection in the event of an accident. Appropriate seat covers can be obtained from a Mercedes-Benz Service Centre.

Head/thorax airbags are intended to offer additional protection for the head and thorax when deployed. However, they do not protect the arms.

Head/thorax airbag

Head/thorax airbags resources/font_symbols/mbsymb5/mbsymb5_0031.png inflate next to the outer seat cushions.

Head/thorax airbags are deployed:

on the side on which an impact occurs
at the start of an accident with a high rate of lateral vehicle deceleration or acceleration, e.g. in a side impact
if the system determines that airbag deployment can offer additional protection to that provided by the seat belt
if the seat belt is fastened
independently of the front airbags
independently of the belt tensioners
on the front-passenger side only if the front-passenger seat occupancy recognition system detects that the front-passenger seat is occupied

Children in the vehicle

If a child is riding in your vehicle, secure the child using a child restraint system appropriate to the size and age of the child and approved for Mercedes-Benz vehicles. Preferably, you should fit the restraint system on a suitable rear seat. Make sure that the child is strapped in throughout the trip.

You can obtain information about the correct child restraint system from any Mercedes-Benz Service Centre.


It is advisable to use Mercedes-Benz care products to clean child restraint systems. You can obtain information about this from any Mercedes-Benz Service Centre.

Risk of injury

Do not leave children unsupervised in the vehicle, even if they are secured in a child restraint system. Children could injure themselves on parts of the vehicle. They could also be seriously or even fatally injured by prolonged exposure to extreme heat or cold.

Do not expose the child restraint system to direct sunlight. The metallic parts of the child restraint system could heat up and the child could be burned by them.

If a child opens the door, other persons could be injured. They could get out and injure themselves or be injured by a passing vehicle.

Risk of injury

An unsecured or incorrectly positioned load increases the risk of injury to the child in the event of:

an accident
a braking manoeuvre
a sudden change of direction

Do not carry heavy or hard objects inside the vehicle unless they are secured. You will find further information in the index under "Features".

Child restraint systems

Mercedes-Benz recommends that you only use the child restraint systems listed on more.

Risk of injury

To reduce the risk of serious or even fatal injury to the child in the event of a sudden change in direction, braking or an accident:

Children less than 1.50 m tall and under twelve years of age must always be secured in special child restraint systems on a suitable vehicle seat. This is necessary because the seat belts are not designed for children of this size.
If you fit a child restraint system to the front-passenger seat, you must move the front-passenger seat as far back as possible.
Children must never travel sitting on the lap of another occupant. Due to the forces occurring in the event of a sudden change of direction, heavy braking or an accident, it would not be possible to restrain the child. The child would be thrown against parts of the vehicle interior and be seriously or even fatally injured.

Risk of injury

If the child restraint system is not fitted correctly to a suitable vehicle seat, it cannot perform its protective function. The child cannot be restrained in the event of a sudden change of direction, heavy braking or an accident. This may lead to serious or even fatal injuries. For this reason, when fitting a child restraint system observe the manufacturer's installation instructions and correct use of the child restraint system.

The entire base of the child restraint system must always be resting on the seat cushion. Never place objects, e.g. a cushion, under the child restraint system.

Only use child restraint systems with their original covers. Only replace damaged covers with genuine Mercedes-Benz covers.

For safety reasons, you should only use child restraint systems which have been approved for use in Mercedes-Benz vehicles.

Child seat on the front-passenger seat

Warning on the front-passenger sun visor

Warning symbol for a rearward-facing child restraint system

Risk of injury

If the front-passenger front airbag is not disabled:

a child secured in a child restraint system on the front-passenger seat can be seriously and even fatally injured by the front-passenger airbag deploying. This is especially likely if the child is in the immediate vicinity of the front-passenger front airbag when it is deployed.
a child must never be secured on the front-passenger seat in a rearward-facing child restraint system.
always move the front-passenger seat to the rearmost position if you secure a child in a forward-facing child restraint system on the front-passenger seat.

The front-passenger front airbag is not disabled if:

no child restraint system with automatic child seat recognition is fitted
if the PASSENGER AIRBAG OFF warning lamp on the centre console is not lit

To draw attention to this danger, there is an appropriate warning sticker on the dashboard as well as on both sides of the sun visor on the front-passenger side.

Information about recommended child restraint systems is available at any Mercedes-Benz Service Centre.

Automatic child seat recognition on the front-passenger seat

resources/font_symbols/mbsymb1b/mbsymb1b_0035.png

PASSENGER AIRBAG OFF warning lamp

The front-passenger seat sensor system for child restraint systems detects whether a special Mercedes-Benz child seat with automatic child seat recognition has been fitted. In such cases, the resources/font_symbols/mbsymb1b/mbsymb1b_0035.png PASSENGER AIRBAG OFF indicator lamp resources/font_symbols/mbsymb5/mbsymb5_0031.png lights up. The front-passenger airbag is deactivated.

Risk of injury

If the resources/font_symbols/mbsymb1b/mbsymb1b_0035.png PASSENGER AIRBAG OFF warning lamp does not light up when the child restraint system is fitted, the front-passenger front airbag has not been disabled. If the front-passenger front airbag is deployed, the child could be seriously or even fatally injured.

Proceed as follows:

Do not use a rearward-facing child restraint system on the front-passenger seat.

Only use a forward-facing child seat on the front-passenger seat and move the front-passenger seat to its rearmost position.
Have the automatic child seat recognition checked at a qualified specialist workshop.

To ensure that the automatic child seat recognition on the front-passenger seat functions correctly, never place objects (such as a cushion) under the child restraint system. The entire base of the child restraint system must always be resting on the seat cushion. An incorrectly fitted child restraint system cannot perform its intended protective function in the event of an accident, and could even lead to injuries.


The head/thorax airbag and the belt tensioner on the front-passenger side are still active even if the front-passenger front airbag is disabled.

Risk of injury

Do not place items of electronic equipment on the front-passenger seat, e.g.:

laptops, when switched on
mobile phones
cards with transponders, e.g. ski passes or access passes

Signals from electronic equipment can cause interference in the automatic child seat recognition sensor system. This can lead to a system malfunction. This may cause the resources/font_symbols/mbsymb1b/mbsymb1b_0035.png PASSENGER AIRBAG OFF warning lamp to light up without there being a child seat with automatic child seat recognition fitted. This means that the front-passenger airbag is not deployed during an accident. It is also possible that the PASSENGER AIRBAG OFF warning lamp will not light up briefly if you turn the key in the ignition lock to position 2.

Suitable positioning of the child restraint system

Weight categories and ages	Child restraint system on the front-passenger seat
Group 0: up to 10 kg; Up to approximately 9 months	as recommended (Only use child restraint systems featuring automatic child seat recognition.) ^, (Move the front-passenger seat to the highest and rearmost position.)
Group 0+: up to 13 kg; Up to approximately 18 months	as recommended^,
Group I: 9 to 18 kg; Between approximately 8 months and 4 years	Universal or as recommended^,
Category II/III: 15 to 36 kg Between approximately 3½ and 12 years	Universal or as recommended

Example of an approval label on the child restraint system

Recommended child restraint systems

Weight categories and ages	Manufacturer	Type	Approval number	Daimler order number	Automatic child seat recognition
Group 0: up to 10 kg; Up to approximately 9 months	Britax-Römer	BABY SAFE PLUS (Move the front-passenger seat to the highest position.)	E1 03 301146	A 000 970 10 00	Yes
Group 0+: up to 13 kg; Up to approximately 18 months	Britax-Römer	BABY SAFE PLUS	E1 03 301146	A 000 970 10 00	Yes
Group I: 9 to 18 kg; Between approximately 8 months and 4 years	Britax-Römer	DUO PLUS	E1 03 301133	A 000 970 11 00	Yes
	Britax-Römer	DUO PLUS	E1 03 301133	A 000 970 16 00	No (For child restraint systems without automatic child seat recognition, move the front-passenger seat to the rearmost position.)
Group II/III: 15 to 36 kg; Between approximately 3½ and 12 years	Britax-Römer	KID	E1 03 301148	A 000 970 12 00	Yes
	Britax-Römer	KID	E1 03 301148	A 000 970 17 00	No