Page 282 of 474

281 Operation
Driving instructions
Refer to the description of the Brake Assist 
System (BAS) (
page 86).
Brake pad wear or a leak in the system may 
be the reason for low brake fluid in the res-
ervoir.
The brake fluid level in the reservoir may 
be too low if the brake warning lamp in 
the instrument cluster (
page 26) 
comes on although the parking brake is 
released (
page 350). Observe additional 
messages that may appear in the multi-
function display (
page 373).
Have the brake system inspected immedi-
ately. Contact an authorized 
Mercedes-Benz Center.All checks and service work on the brake 
system should be carried out by qualified 
technicians only. Contact an authorized 
Mercedes-Benz Center.
Install only brake pads and brake fluid 
recommended by Mercedes-Benz.
After hard braking, it is advisable to drive 
on for some time, rather than immediately 
park, so that the air stream will cool down 
the brakes faster.High-performance brake system 
(SLK 55 AMG only)
The high-performance brake system is de-
signed to operate under the extremely high 
operating demands required to accommo-
date the performance capabilities of the 
vehicle. The brakes may produce a squeak-
ing-type noise depending on the
vehicle speed
brake force applied
ambient conditions, e.g. temperature 
and humidity
As with any brake system, the wear of indi-
vidual brake system components such as 
brake pads or discs strongly depends on 
your driving style and the conditions under 
which you operate the vehicle. Thus, a driv-
ing style calling for high demand braking 
will cause your vehicle’s brakes to wear 
more quickly.
Warning!G
Make sure not to endanger any other road 
users when carrying out these braking 
maneuvers.
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.
!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 prevent overheating of the brakes and 
reduces brake pad wear. 
     
        
        Page 283 of 474

282 Operation
Driving instructions
Driving off
Apply the brakes to test them briefly after 
driving off. Perform this procedure only 
when the road is clear of other traffic.
Warm up the engine smoothly. Do not 
place full load on the engine until the oper-
ating temperature has been reached.Parking
Warning!G
New vehicle brake pads and discs, and 
replacement brake pads and discs may take 
several hundred miles of driving until they 
provide optimum braking efficiency. Until 
that time, you may need to use increased 
brake pedal pressure while braking. Please 
be aware of this and adjust your driving and 
braking accordingly during this break-in 
period.
Excessive high demand braking will cause 
correspondingly high brake wear. Please be 
attentive to the brake warning lamp in the 
instrument cluster and brake condition mes-
sages in the multifunction display. Especial-
ly for high performance driving, it is 
important to maintain the brake system and 
have it checked regularly.
!When starting off on a slippery surface, do 
not allow a drive wheel to spin for an extended 
period with the ESP
® switched off. Doing so may 
cause serious damage to the drivetrain which is 
not covered by the Mercedes-Benz Limited 
Warranty.
!Simultaneously depressing the accelerator 
pedal and applying the brake reduces engine 
performance and causes premature brake and 
drivetrain wear.
Warning!G
Do not park this vehicle in areas where 
combustible materials such as grass, hay or 
leaves can come into contact with the hot 
exhaust system, as these materials could be 
ignited and cause a vehicle fire.
To reduce the risk of personal injury or 
damage to the vehicle drivetrain as a result 
of vehicle movement, before turning off the 
engine and leaving the vehicle always:
Keep right foot on brake pedal.
Pull the parking brake lever up as many 
notches as possible. 
Manual transmission: Move the gear-
shift lever into first or reverse gear.
Automatic transmission*: Move the 
gear selector lever to position P. 
     
        
        Page 351 of 474

350 Practical hints
What to do if …
ProblemPossible cause/consequenceSuggested solution
USA only:
;
Canada only:
3
The red brake warning lamp 
comes on when the engine is 
running and an acoustic warning 
sounds.You are driving with the parking brake 
set.Release the parking brake (page 53).
The red brake warning lamp 
comes on when the engine is 
running.There is insufficient brake fluid in the 
reservoir.Risk of accident!
Carefully stop the vehicle in a safe loca-
tion or as soon as it is safe to do so.
Apply the parking brake (page 59).
Read and observe messages in the dis-
play (
page 360).
Contact an authorized Mercedes-Benz 
Center.
Do not add brake fluid! This will not solve 
the problem.
Warning!G
Driving with the brake warning lamp illumi-
nated can result in an accident. Have your 
brake system checked immediately if the 
brake warning lamp stays on.
Do not add brake fluid before checking the 
brake system. Overfilling the brake fluid 
reservoir can result in spilling brake fluid on 
hot engine parts and the brake fluid catch-
ing fire. You can be seriously burned.!If you find that the brake fluid in the brake 
fluid reservoir has fallen to the minimum mark or 
below, have the brake system checked for brake 
pad thickness and leaks. 
     
        
        Page 366 of 474

365 Practical hints
What to do if …
Display message Possible cause/consequencePossible solution
Front-passenger
Airbag Enabled
See Operator’s
ManualThe passenger front air bag and the 
passenger-side knee bag are 
activated while driving even though a 
child, small individual, or object below 
the system’s weight threshold is on 
the passenger seat, or the passenger 
seat is empty. Objects on the seat or 
forces acting on the seat may make 
the system sense supplemental 
weight.Stop the vehicle in a safe location as soon as possible and check the 
passenger seat for the following:
Switch off the ignition (page 37).
Apply the parking brake (page 59).
Remove child and child restraint from passenger seat.
Make sure that no objects which are applying supplemental weight 
onto the seat are present. The system may recognize such supple-
mental weight and sense that an occupant on the passenger seat is 
of a greater weight than actually present.
Keep the seat unoccupied, close the passenger door and switch on 
the ignition (
page 37).
Monitor the 75indicator lamp on the center console 
(
page 29) and the multifunction display in the instrument cluster 
(
page 121) for the following:
(Continued on next page) 
     
        
        Page 368 of 474
367 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
Front-passenger
Airbag Disabled
See Operator’s
ManualThe passenger front air bag and the 
passenger-side knee bag are 
deactivated while driving even though 
an adult or someone larger than a 
small individual is occupying the front 
passenger seat. Forces acting on the 
seat may make the system sense a 
decrease in weight.Stop the vehicle in a safe location as soon as possible and check the 
passenger seat for the following:
Switch off the ignition (page 37).
Apply the parking brake (page 59).
Have the passenger vacate the seat and exit the vehicle.
Keep the seat unoccupied, close the passenger door and switch on 
the ignition (
page 37).
Monitor the 75indicator lamp on the center console 
(
page 29) and the multifunction display in the instrument cluster 
(
page 121) for the following:
(Continued on next page) 
     
        
        Page 372 of 474
371 Practical hints
What to do if …
Symbol messages
Display symbolDisplay messagePossible cause/consequencePossible solution
ÊThis message will appear whenever 
the trunk lid is open.Close the trunk lid.
OYou are driving with the hood open.Risk of accident!
Stop the vehicle in a safe location or as soon 
as it is safe to do so.
Apply the parking brake (page 59).
Close the hood (page 294).
JYou are driving with one or more 
doors open.Close the doors.
•The cooling fan for the coolant is 
malfunctioning.Observe the coolant temperature display 
(
page 127).
If the coolant temperature is below 120°C, 
you may continue driving to the nearest 
specialist workshop.
Avoid heavy loads on the engine (e.g. by 
driving uphill) as well as stop-and-go traffic.
Have the fan replaced as soon as possible. 
     
        
        Page 373 of 474
372 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
#The battery is no longer charging. 
Possible causes:
Alternator malfunctioning
Broken poly-V-belt
Do not forget that the brake system 
requires electrical energy and may 
be operating with restricted capa-
bility. Considerably greater brake 
pedal force is required and the stop-
ping distance is increased.
Stop the vehicle immediately in a safe loca-
tion and check the poly-V-belt.
If it is broken:
Do not continue to drive. 
Otherwise, the engine will overheat due 
to an inoperative water pump which may 
result in damage to the engine. Contact 
an authorized Mercedes-Benz Center.
If it is in order:
Contact an Mercedes-Benz Center 
immediately. Adjust driving to be consis-
tent with reduced braking responsive-
ness.
USA only:
;
Canada only:
!
Release
Parking BrakeYou are driving with the parking 
brake set.Release the parking brake (page 53).  
     
        
        Page 374 of 474

373 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
USA only:
;
Canada only:
3
Check
Brake Fluid LevelThere is insufficient brake fluid in 
the reservoir.Risk of accident! 
Stop the vehicle in a safe location or as soon as 
it is safe to do so.
Turn off the engine.
Apply the parking brake (page 59).
Do not drive any further.
Contact an authorized Mercedes-Benz Center.
Do not add brake fluid! This will not solve the 
problem.
2Brake WearThe brake pads have reached their 
wear limit.Have the brake pads replaced as soon as 
possible.
Warning!G
Driving with the message Check Brake 
Fluid Level
 displayed can result in an 
accident. Have your brake system checked 
immediately. Do not add brake fluid before 
checking the brake system. 
Overfilling the brake fluid reservoir can 
result in spilling brake fluid on hot engine 
parts and the brake fluid catching fire. You 
can be seriously burned.!If you find that the brake fluid in the brake 
fluid reservoir has fallen to the minimum mark or 
below, have the brake system checked for brake 
pad thickness and leaks.
!Brake pad thickness must be visually 
checked by a qualified technician at the intervals 
specified in the Maintenance Booklet.