
67 Restraint systems
Te ch n i c a l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index Emergency tensioning device (ETD)
The seat belts for the front and outer rear seats are 
equipped with emergency tensioning devices. These 
tensioning devices are located in each belt’s inertia reel 
and become operationally ready with the electronic key 
in steering lock position 1 or 2.
The ETDs for the driver and front seat passenger are 
designed to activate only when the seat belts are 
fastened and during certain frontal impacts exceeding 
the first threshold of the SRS and in rear impacts 
exceeding a preset severity level. They remove slack 
from the belts in such a way that the seat belts fit more 
snugly against the body restricting its forward 
movement as much as possible.
The rear seat belt ETDs will deploy in the same 
circumstances whether or not the seat belts are 
fastened.In cases of other frontal impacts, angled impacts, roll-
overs, certain side impacts, or other accidents without 
sufficient frontal or rear forces, the emergency 
tensioning devices will not be activated. The driver and 
passengers will then be protected by the fastened seat 
belts and inertia reel in the usual manner.
For seat belt and emergency tensioning device safety 
guidelines, see page 75.
Note:
The front ETD activates only if the front seat is occupied 
and the seat belt is fastened.
Objects heavier than 20 lbs (9 kg) on the front 
passenger seat can appear to the SRS to indicate the 
presence of an occupant in that seat which causes the 
passenger front airbag to deploy and the ETD to activate 
in a crash exceeding the appropriate threshold. 

68 Restraint systems
Te ch n i c a l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
Airbags
1Driver airbag
2Front passenger airbagThe most effective occupant restraint system yet 
developed for use in production vehicles is the seat belt. 
In some cases, however, the protective effect of a seat 
belt can be further enhanced by an airbag.
In conjunction with wearing the seat belts, the driver 
and front passenger airbags can provide increased 
protection for the driver and front passenger in certain 
frontal impacts exceeding preset thresholds.
Door mounted side impact and head protection window 
curtain airbags can provide increased protection to 
belted outboard occupants on the impacted side of the 
vehicle in side impacts exceeding its preset threshold.
The operational readiness of the airbag system is 
verified by the indicator lamp SRS in the instrument 
cluster when turning the electronic key in steering lock 
to position 1 or 2. If no fault is detected, the lamp will go 
out after approximately 4 seconds; after the lamp goes 
out, the system continues to monitor the components 
and circuitry of the airbag system and will indicate a 
malfunction by coming on again. If the lamp does not 
come on at all or if it fails to extinguish after 
approximately 4 seconds or if it comes on thereafter, a 
malfunction in the system has been detected.
2
1
P91.60-2248-27 

69 Restraint systems
Te ch n i c a l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index The following system components are monitored or 
undergo a selfcheck: crash-sensor(s), airbag ignition 
circuits, front seat belt buckles, emergency tensioning 
devices, seat sensor.
Initially, when the electronic key is turned from steering 
lock position 0 to position 1 or 2, malfunctions in the 
crash-sensors are detected and indicated (the SRS 
indicator lamp stays on longer than 4 seconds or does 
not come on).
Have the system checked at your authorized 
Mercedes-Benz Center immediately.
In the operational mode, after the indicator lamp has 
gone out following the initial check, interruptions or 
short circuits in the airbag ignition circuit and in the 
driver and front passenger seat belt buckle harnesses, 
and low voltage in the entire system are detected and 
indicated.Note:
See page 246 for information on the Supplemental 
Restraint System (SRS) indicator lamp.
Wa r n i n g !
In the event a malfunction of the SRS is indicated 
as outlined above, the SRS may not be operational. 
For your safety, we strongly recommend that you 
visit an authorized Mercedes-Benz dealer 
immediately to have the system checked; otherwise 
the SRS may not be activated when needed in an 
accident, which could result in serious or fatal 
injury, or it might deploy unexpectedly and 
unnecessarily which could also result in injury. 

71 Restraint systems
Te ch n i c a l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index Side impact airbags
The side impact airbags are designed to activate only in 
certain side impacts exceeding a preset threshold. Only 
the side impact airbags on the impacted side of the 
vehicle deploy.
The side impact airbag for the front passenger deploys 
only if the front passenger seat is occupied.
Side impact airbags operate best in conjunction with a 
properly positioned and fastened seat belt.
Note:
Heavy objects on front passenger seat can cause the 
front passenger-side impact airbag to deploy in a crash.Window curtain airbags
The head protection window curtain airbags afford 
greater protection against injuries to the head and 
upper body. They fill up in the area between the A and 
C pillars (see arrows) between the side windows and an 
occupant’s head.
The window curtain airbags are designed to activate 
only in certain side impacts exceeding a preset 
threshold. Only the head protection window curtain 
airbag on the impacted side of the vehicle deploys. 

72 Restraint systems
Te ch n i c a l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
Important!
Airbags are designed to activate only in certain 
frontal (front airbags) impacts, or side (side impact 
and head protection window curtain airbags) 
impacts which exceed preset thresholds.
Only during these types of impacts, if of sufficient 
severity to meet the deployment thresholds, will 
they provide their supplemental protection.
The driver and passenger should always wear their 
seat belts, otherwise it is not possible for the airbags 
to provide their supplemental protection.
In cases of other frontal impacts, angled impacts, 
roll-overs, other side impacts, rear collisions, or 
other accidents, the airbags will not be activated. 
The driver and passengers will then be protected by 
the fastened seat belts.
We caution you not to rely on the presence of the 
airbags in order to avoid wearing your seat belt.
Wa r n i n g !
Airbags are designed to reduce the potential of 
injury in certain frontal (front airbags) impacts, or 
side (side impact and head protection window 
curtain airbags) impacts which may cause 
significant injuries, however, no system available 
today can totally eliminate injuries and fatalities.The activation of the SRS temporarily releases a 
small amount of dust from the airbags. This dust, 
however, is neither injurious to your health, nor 
does it indicate a fire in the vehicle. The dust might 
cause some temporary breathing difficulty for 
people with asthma or other breathing trouble. To 
avoid this, you may wish to get out of the vehicle as 
soon as it is safe to do so. If you have any breathing 
difficulty but cannot get out of the vehicle after the 
airbag inflates, then get fresh air by opening a 
window or door. 

73 Restraint systems
Te ch n i c a l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index Your vehicle was originally equipped with airbags 
which are designed to activate in certain impacts 
exceeding a preset threshold to reduce the potential 
and severity of injury. It is important to your safety 
and that of your passenger that you replace deployed 
airbags and repair any malfunctioning airbags to 
ensure the vehicle will continue to provide 
supplemental crash protection for occupants.
Wa r n i n g !
To reduce the risk of injury when the front airbags 
inflate, it is very important for the driver and front 
passenger to always be in a properly seated 
position and to wear their seat belts.For maximum protection in the event of a collision 
always be in normal seated position with your back 
against the backrest. Fasten your seat belt and 
ensure that it is properly positioned on your body.Since the airbag inflates with considerable speed 
and force, a proper seating and hands on steering 
wheel position will help to keep you at a safe 
distance from the airbag. Occupants who are 
unbelted, out of position or too close to the airbag 
can be seriously injured by an airbag as it inflates 
with great force in the blink of an eye:
• Sit properly belted in an upright position with 
your back against the backrest.• Adjust the driver’s seat as far as possible 
rearward, still permitting proper operation of 
vehicle controls. distance from the center of 
the driver’s breastbone to the center of the 
airbag cover on the steering wheel must be at 
least ten inches (25 cm) or more. You should be 
able to accomplish this by a combination of 
adjustments to the seat and steering wheel. If 
you have any problems, please see your 
authorized Mercedes-Benz Center.• Do not lean with your head or chest close to the 
steering wheel or dashboard.• Keep hands on the outside of steering wheel 
rim. Placing hands and arms inside the rim 
can increase the risk and potential severity of 
hand / arm injury when driver front airbag 
inflates.• Adjust the front passenger seat as far as 
possible rearward from the dashboard when 
the seat is occupied. 

74 Restraint systems
Te ch n i c a l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
• Occupants, especially children, should never 
lean their heads in the area of the door where 
the side airbag inflates. This could result in 
serious injuries or death should the airbag be 
triggered. Always sit upright, properly use the 
seatbelts and appropriate size infant or child 
restraint system• Children 12 years old and under must never 
ride in the front seat, except in a Mercedes-
Benz authorized Baby Smart
TM compatible 
child seat, which operates with the 
BabySmart
TM system installed in the vehicle to 
deactivate the passenger front airbag when it 
is properly installed. Otherwise they will be 
struck by the airbag when it inflates in a crash. 
If this happens, serious or fatal injury can 
result.
Failure to follow these instructions can result in 
severe injuries to you or other occupants.
Wa r n i n g !
Accident research shows that the safest place for 
children in an automobile is in the rear seat. 
Should you choose to place a child 12 years old or 
under in the front passenger seat of your vehicle, 
you must properly use a BabySmart
TM child 
restraint which will turn off the passenger side 
front airbag. BabySmart
TM will not, however, turn 
off the vehicle’s side impact airbag.
It should be noted that with respect to both front 
and rear side impact airbags there is a possibility 
for a side airbag related injury if occupants, 
especially children, are not properly seated or 
restrained when next to a side airbag which needs 
to deploy rapidly in a side impact in order to do its 
job.To help avoid the possibility of injury, please follow 
these guidelines: (1) occupants, especially 
children, should never place their bodies or lean 
their heads in the area of the door where the side 
airbag inflates. This could result in serious 
injuries or death should the side airbag be 
activated; (2) always sit upright, properly use the 
seat belts and use an appropriately sized infant or 
child restraint system for all children 12 years old 
or under; and (3) always wear seat belts properly. 

75 Restraint systems
Te ch n i c a l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index Safety guidelines for the seat belt, emergency 
tensioning device and airbag
If you believe that, even with the use of these 
guidelines, it would be safer for your rear seat 
occupants to have both rear door mounted side 
airbags deactivated, then deactivation can be 
accomplished upon your written election to do so at 
your authorized Mercedes-Benz Center at an 
additional cost. Please contact your local 
authorized Mercedes-Benz Center or call our 
Customer Assistance Center at 1-800-FOR-
MERCedes (1-800-367-6372) for details.Wa r n i n g !
• Damaged seat belts or belts that were highly 
stressed in an accident must be replaced and 
their anchoring points must also be checked. 
Use only belts installed or supplied by an 
authorized Mercedes-Benz Center.• Do not pass belts over sharp edges.• Do not make any modification that could 
change the effectiveness of the belts.
• Ai rba gs an d  E T Ds  are d esi gned  to fun c tion  on  a 
one-time-only basis. An airbag or emergency 
tensioning device (ETD) that was activated 
must be replaced.• No modifications of any kind may be made to 
any components or wiring of the SRS. This 
includes changing or removing any component 
or part of the SRS, the installation of additional 
trim material, badges etc. over the steering 
wheel hub, front passenger airbag cover, door 
trim panels, or door frame trims, and 
installation of additional electrical /electronic 
equipment on or near SRS components and 
wiring. Keep area between airbags and 
occupants free of objects (e.g. packages, 
purses, umbrellas, etc.).• Do not hang items such as coat hangers from 
the coat hooks or handles over the door. These 
items may turn into projectiles and cause head 
and other injuries when curtain airbag is 
deployed.• An airbag system component within the 
steering wheel gets hot after the airbag has 
inflated. Do not touch.