
55 Restraint systems
Technical
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index Press switch (4) to adjust the height of the seat belt 
outlet so that the shoulder portion is located as close as 
possible to the middle of your shoulder.
The shoulder portion of the seat belt must be pulled 
snug and checked for snugness immediately after 
engaging it and during driving. Tighten the lap portion 
to a snug fit by pulling shoulder portion up.Operation of seat belts
The inertia reel stops the belt from unwinding during 
sudden vehicle stops or when quickly pulling on the 
belt.
The locking function of the reel may be checked by 
quickly pulling out the belt.
3
2
1
P91.40-0346-26
4 

56 Restraint systems
Technical
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
Caution!
For safety reasons, avoid adjusting the seat or backrest 
into positions which could affect the correct seat belt 
positioning.
Unfastening of seat belts
Push the release button (3) in the belt buckle (2).
Allow the retractor to completely rewind the seat belt by 
guiding the latch plate (1).
Wa r n i n g !
USE SEAT BELTS PROPERLY.• Each occupant should wear their seat belt at all 
times, because seat belts help reduce the 
likelihood of and potential severity of injuries 
in accidents, including rollovers. The 
integrated restraint system includes "SRS" 
(driver airbag, passenger airbag, door mounted 
side impact airbags), "ETR" (seat belt 
emergency tensioning retractors), and front 
seat knee bolsters. The system is designed to 
enhance the protection offered to properly 
belted occupants in certain frontal (front 
airbags) and side (side impact airbags) impacts 
which exceed preset deployment thresholds.• Never wear belts over rigid or breakable 
objects in or on your clothing, such as 
eyeglasses, pens, keys etc., as these might 
cause injuries.• Position the lap belt as low as possible on your 
hips and not across the abdomen. If the belt is 
positioned across your abdomen, it can cause 
serious injuries in a crash. 

57 Restraint systems
Technical
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
BabySmart
TM is a trademark of Siemens Automotive Corp.
• Never wear the shoulder belt under your arm, 
against you neck or off your shoulder. In a 
crash, your body would move too far forward. 
That would increase the chance of head and 
neck injuries. The belt would also apply too 
much force to the ribs or abdomen, which 
could severely injure internal organs such as 
your liver or spleen.• Each seat belt must never be used for more 
than one person at a time. Do not fasten a seat 
belt around a person and another person or 
other objects.• Belts should not be worn twisted. In a crash, 
you wouldn’t have the full width of the belt to 
manage impact forces. The twisted belt against 
your body could cause injuries.• Pregnant women should also use a lap-
shoulder belt. The lap belt portion should be 
positioned as low as possible on the hips to 
avoid pressure on the abdomen.• Never place your feet on the instrument panel 
or on the seat. Always keep both feet on the 
floor in front of the seat.
Wa r n i n g !
USE CHILD RESTRAINTS PROPERLY.
Children 12 years old and under must never ride in 
this vehicle, except in a Mercedes-Benz authorized 
BabySmart
TM compatible child seat, which operates 
with the BabySmart
TM system installed in the 
vehicle to deactivate the passenger side front 
airbag wh en 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 will 
result.
Infants and small children must be seated in an 
appropriate infant or child restraint system, which 
is properly secured with the vehicle’s seat belt, 
fully in accordance with the child seat 
manufacturer’s instructions.A child’s risk of serious or fatal injuries is 
significantly increased if the child restraints are 
not properly secured in the vehicle and the child is 
not properly secured in the child restraint.Adjust the passenger seat as far as possible 
rearward from the dashboard when the seat is 
occupied. 

58 Restraint systems
Technical
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
BabySmart
TM airbag deactivation system
Special BabySmart
TM compatible child seats, designed 
for use with the Mercedes-Benz system and available at 
any authorized Mercedes-Benz Center are required for 
use with the BabySmart
TM airbag deactivation system.
With the special child seat properly installed, the 
passenger side front airbag will not deploy. The 7 
indicator lamp located in the dashboard will be 
illuminated, except with key removed or in steering lock 
position 0. The system does not deactivate the door 
mounted side impact airbag.Self-test BabySmart
TM
without special child seat installed
After turning key in steering lock to position 1 or 2, the 
7 indicator lamp located in the dashboard comes on 
for approx. 6 seconds and then extinguishes.
If the indicator lamp should not come on or is 
continuously lit, the system is not functioning. You must 
see an authorized Mercedes-Benz Center before seating 
any child on the front passenger seat.BabySmart
TM is a trademark of Siemens Automotive Corp.
Wa r n i n g !
The BabySmart
TM airbag deactivation system will 
ONLY work with a special child seat designed to 
operate with it. It will not work with child seats 
which are not BabySmart
TM compatible.
Never place anything between seat cushion and 
child seat (e.g. pillow), since it reduces the 
effectiveness of the deactivation system.Follow the manufacturer’s instructions for 
installation of special child seats.The passenger front airbag will not deploy only if 
the 7 indicator lamp remains illuminated.
Please be sure to check the indicator every time 
you use the special system child seat.
Should the light go out while the restraint is 
installed, please check installation. If the light 
remains out, do not use the BabySmart
TM restraint 
to transport children on the front passenger seat 
until the system has been repaired. 

59 Restraint systems
Technical
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index Supplemental restraint system (SRS)
Airbags are intended as a supplement to seat belts. 
Airbags alone cannot protect as well as airbags plus 
seat belts in impacts for which the airbags were 
designed to operate, and do not afford any protection 
whatsoever in crashes for which the airbags are not 
designed to deploy.
The SRS uses two crash severity levels (thresholds) to 
activate either the emergency tensioning retractor (ETR) 
or front airbag or both. Activation depends on the 
direction and severity of the impact exceeding the 
preset thresholds and whether the seat belt is fastened.
Seat belt fastened
• first threshold exceeded:
ETR activates
• second threshold exceeded:
airbag also activates
Seat belt not fastened
• first threshold exceeded:
airbag activates, but not ETR
Driver and passenger systems operate independently of 
each other.Emergency tensioning retractor (ETR)
The seat belts are equipped with emergency tensioning 
retractors. These tensioning retractors are located in 
each belt’s inertia reel and become operationally ready 
with the key in steering lock position 1 or 2.
The emergency tensioning retractors are designed to 
activate only when the seat belts are fastened during 
frontal and front-angled impacts and rear 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.
In cases of other frontal impacts, rollovers, certain side 
impacts, rear collisions or other accidents without 
sufficient frontal or rear impact forces, the emergency 
tensioning retractors will not be activated. The driver 
and passenger will then be protected by the fastened 
seat belts and inertia reel in the usual manner.
For seat belt and emergency tensioning retractor safety 
guidelines see page 66. 

60 Restraint systems
Technical
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
Airbags 1Driver airbag
2Passenger front airbag
3Side impact airbags
The 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 passenger airbags can provide increased protection 
for the driver and passenger in certain frontal impacts 
exceeding preset thresholds. Door mounted side impact 
airbags can provide increased protection to belted 
occupants on the impacted side of the vehicle in side 
impacts exceeding its preset thresholds.
The operational readiness of the airbag system is 
verified by the indicator lamp "SRS" in the instrument 
cluster when turning the key in steering lock to 
position 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  

61 Restraint systems
Technical
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index 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.
The following system components are monitored or 
undergo a selfcheck: crash-sensor(s), airbag ignition 
circuits, seat belt buckles, emergency tensioning 
retractors, seat sensor.
Initially, when the key is turned from steering lock 
position 0 to positions 1 or 2, malfunctions in the crash-
sensor are detected and indicated (the “SRS” indicator 
lamp stays on longer than 4 seconds or does not come 
on). 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 passenger seat belt buckle harnesses, and 
low voltage in the entire system are detected and 
indicated.Have the system checked at your authorized 
Mercedes-Benz Center immediately.
Wa r n i n g !
In the event a malfu nction of th e “SRS” is indic ated 
as outlined above, the “SRS” may not be 
operational. For your safety, we strongly 
recommend that you visit an authorized 
Mercedes-Benz Center 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 unnecessary which could also 
result in injury. 

62 Restraint systems
Technical
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
Front airbags
The driver and passenger front airbags are designed to 
activate only in certain frontal impacts exceeding a 
preset threshold.
The passenger front airbag deploys only if the front 
passenger seat is occupied, and the 7 indicator la mp 
in the dashboard is not illuminated.
Note:
Heavy objects on the 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 
in a crash exceeding the appropriate threshold.Side impact airbags
The side impact airbags are designed to activate only in 
certain side impacts exceeding a preset threshold. Only 
the side impact airbag on the impacted side of the 
vehicle deploy.
The passenger side impact airbag deploys only if the 
passenger seat is occupied.
Side impact airbags operate best in conjunction with a 
properly positioned and fastened seat belt.
Note:
Heavy objects on passenger seat can cause the 
passenger door side impact airbag to deploy in a crash.
Important!
Airbags are designed to activate only in certain 
frontal (front airbags) impacts, or side (side impact 
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 must always wear their 
seat belts, otherwise it is not possible for the airbags 
to provide their intended supplemental protection.