68 Safety and SecurityOccupant safetyPreventive occupant safety (PRE-SAFE)
Your vehicle automatically takes preven-
tive measures to better protect the occu-
pants in the following hazardous 
situations:
You execute an emergency braking ma-
neuver and the Brake Assist System 
(page 78) is activated.
The PRE-SAFE system detects a critical 
driving dynamics situation.In such cases, the following systems are 
automatically activated:
A front seat belt with the seat belt 
buckled is pre-tensioned electrically.
If the occupied front passenger seat or 
rear seats are in an unfavorable posi-
tion, they are adjusted to a better posi-
tion. Rear seat adjustment occurs only 
in vehicles with individual seats* in the 
rear.
The sliding/pop-up roof closes if the 
vehicle is in a severe skid or is spin-
ning.
If the seat belts do not release:
Adjust the backrest or seat slightly to 
the rear until the seat belt tension is di-
minished.
The locking mechanism releases.
Warning
G
The PRE-SAFE system is intended to reduce 
the effects of an accident on properly seat 
belted vehicle occupants. Despite having 
the PRE-SAFE systems in your car, the pos-
sibility of injuries occurring as a result of an 
accident cannot be totally eliminated. 
Therefore you should always drive carefully 
and adjust your driving to the prevailing 
road, weather, and traffic conditions.
iThe PRE-SAFE systems are activated in 
the previously described circumstanc-
es only at speeds exceeding 22 mph 
(35 km/h).
When the driving dynamic situation has 
passed without an accident occurring, 
the pre-tensioning on the seat belts is 
deactivated.
You can then adjust the seats and the 
sliding sunroof to their previous posi-
tion. 
333 Practical hints
What to do if …?
Display symbol
Display message
Possible cause
Possible solution
. 
TURN SIGNAL, L
CHECK LAMP!
 
SUBSTITUTE LAMP ON!
The left rear turn signal lamp is malfunc-
tioning. A back-up bulb is being used.
Replace the bulb as soon as possible.
TURN SIGNAL, R
CHECK LAMP!
 
SUBSTITUTE LAMP ON!
The right rear turn signal lamp is malfunc-
tioning. A back-up bulb is being used.
Replace the bulb as soon as possible.
TURN SIG. MIRROR, L
CHECK LAMP!
The left turn signal in the side mirror is 
malfunctioning. This message will only ap-
pear if all light emitting diodes have 
stopped working.
Visit an authorized Mercedes-Benz Cen-
ter as soon as possible.
TURN SIG. MIRROR, R
CHECK LAMP!
The right turn signal in the side mirror is 
malfunctioning. This message will only ap-
pear if all light emitting diodes have 
stopped working.
Visit an authorized Mercedes-Benz Cen-
ter as soon as possible.
<
SEAT BELT SYSTEM
VISIT WORKSHOP!
The seat belt system is malfunctioning.
Visit an authorized Mercedes-Benz 
Center as soon as possible.
K 
CLOSE
SUNROOF!
You have opened the driver’s door with 
the SmartKey removed from the starter 
switch and the sliding/pop up roof open.
Close the sliding/pop-up roof 
(page 199).
J 
CLOSE
SUNROOF!
You have opened the driver’s door with 
the SmartKey removed from the starter 
switch and the sliding/pop up roof open.
Close the sliding/pop-up roof 
(page 199).