81 Safety and Security
Driving safety systems
The SBC brake servo assistance switches 
off automatically
approximately two minutes after you 
turned the SmartKey in the starter 
switch to position0 or removed the 
SmartKey 
approximately two minutes after you 
pressed the KEYLESS-GO* start/stop 
button to turn off the engine or power 
supply and opened the driver’s door 
(with driver’s door open, the starter 
switch is set to position 0, same as 
SmartKey removed from starter 
switch) 
approximately 20 seconds after you 
locked the vehicle from outside 
Note on driving with the SBC
Following extended periods of only mi-
nor loads to your brake system, you 
should occasionally apply the brakes 
when traveling at high speeds. This im-
proves the grip of the brake pads. 
After driving on wet or snow-covered 
roads, you should apply your brakes 
firmly before parking your vehicle. This 
produces heat which serves to dry the 
brake disks and help prevent corro-
sion. 
On long and steep grades, shift to a 
lower gear (gear range1, 2, or 3) to 
prevent the brakes from overheating 
and to reduce brake wear.
After hard braking, it is advisable to 
drive on for some time so that the air 
stream will cool down the brakes fast-
er. 
Only Mercedes-Benz approved compo-
nents (e.g. brake pads) should be in-
stalled on your vehicle. Brake pads not 
approved by Mercedes-Benz may im-
pair the safety of your vehicle.
Warning!
G
Have brake pad replacement and other work 
on the SBC brake system carried out by 
qualified technicians only. Contact your 
Mercedes-Benz Center for further informa-
tion. The SBC brake system must be deacti-
vated prior to working on the system. High 
pressure is intermittently built up in the sys-
tem as part of its automatic self-test. In ad-
dition, the system is automatically activated 
when the vehicle is unlocked by SmartKey, 
when the driver or passenger door is 
opened, when the starter switch is turned to 
position
1, when the brake pedal is de-
pressed or when the parking brake is re-
leased. Failure to deactivate the system 
prior to maintenance will cause brake pis-
tons to extend and brake fluid to leak, which 
may result in injuries (contusions and acid 
burns). Extended brake pistons may also 
cause injury. 
Warning!
G
Be very careful not to endanger other road 
users when you apply the brakes.  
269 Operation
Driving instructions
To help prevent brake disk corrosion after 
driving on wet road surfaces (particularly 
salted roads), it is advisable to brake the 
vehicle with considerable force prior to 
parking. The heat generated serves to dry 
the brakes.
If your brake system is normally only sub-
j e c t e d  t o  m o d e r a t e  l o a d s ,  y o u  s h o u l d  o c c a -
sionally test the effectiveness of the 
brakes by applying above-normal braking 
pressure at higher speeds. This will also 
enhance the grip of the brake pads. If the parking brake is released and the 
brake warning lamp in the instrument clus-
ter stays on, there is a malfunction in the 
SBC brake system (
page 79) or the 
brake fluid level in the reservoir is too low.
Brake pad wear or a leak in the system may 
be the reason for low brake fluid in the res-
ervoir.
Have the brake system inspected by quali-
fied technicians immediately. Contact your 
authorized Mercedes-Benz Center.
All checks and service work on the brake 
system should be carried out by qualified 
technicians only. Contact your authorized 
Mercedes-Benz Center.
Only install brake pads and brake fluid rec-
ommended by Mercedes-Benz.
After hard braking, it is advisable to drive 
on for some time, rather than immediately 
parking, so that the air stream will cool 
down the brakes faster.
!Be very careful not to endanger other 
road users when you apply the brakes.
Refer to the description of the Brake 
Assist System (BAS) (
page 76).
Warning!
G
If other than recommended brake pads are 
installed, or other than recommended brake 
fluid is used, the braking properties of the 
vehicle can be degraded to an extent that 
safe braking is substantially impaired. This 
could result in an accident.
Be certain to read and observe the warning 
notices on brake pad replacement 
(page 326).!When driving down long and steep 
grades, relieve the load on the brakes 
by shifting into a lower gear to use the 
engine’s braking power. This helps pre-
vent overheating of the brakes and re-
duces brake pad wear.