Page 371 of 506
369 Practical hints
What to do if …
Text messagesDisplay
Display message
Possible cause
Possible solution
ABS
Malfunction
Visit workshop
The ABS has detected a malfunction
and has switched off.
The ESP and the BAS are also deac-
tivated.
The SBC brake system is still func-
tioning normally but without the ABS
available.
Continue driving with added caution.
Wheels will lock during hard braking, reduc-
ing steering capability.
Have the system checked at an authorized
Mercedes-Benz Center as soon as possible.
Failure to follow these instructions increases
the risk of an accident.
Display malfunction
Visit workshop
The ABS or the ABS display is mal-
functioning.
Continue driving with added caution.
Wheels will lock during hard braking, reduc-
ing steering capability.
Visit an authorized Mercedes-Benz Center
as soon as possible.
Failure to follow these instructions increases
the risk of an accident.
Page 374 of 506

372 Practical hintsWhat to do if …Display
Display message
Possible cause
Possible solution
ESP
Malfunction
Visit workshop
The ESP has detected a malfunction
and switched off.
The ABS may not be operational.
The SBC brake system is still func-
tioning normally but without the ESP
available.
Continue driving with added caution.
Have the system checked at an authorized
Mercedes-Benz Center as soon as possible.
Failure to follow these instructions increases
the risk of an accident.
unavailable
See Operator’s Manual
The ESP is deactivated because the
power supply was interrupted.
The SBC brake system is still func-
tioning normally but without the ESP
available.
Synchronize the ESP. With the vehicle sta-
tionary, turn the steering wheel completely
to the left and then to the right to synchro-
nize the ESP.
If the ESP message does not go out:
Continue driving with added caution.
Have the system checked at an authorized
Mercedes-Benz Center as soon as possible.
Failure to follow these instructions increases
the risk of an accident.
!When synchronizing the ESP, make
sure you can turn the steering wheel in
both directions as far as it will go with-
out the wheels hitting any objects, e.g.
a road curb.
Page 381 of 506

379 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
#
Battery/Alternator
Stop vehicle
The battery is malfunctioning.
The SBC brake system requires electrical
energy and therefore has only limited op-
eration. Considerably greater brake pedal
force is required and the stopping dis-
tance is increased.
Stop the vehicle as soon as it is safe
to do so. Adjust driving to be consis-
tent with reduced braking responsive-
ness.
Notify an authorized Mercedes-Benz
Center.
Low voltage
Start engine
The battery has insufficient voltage.
Start the engine (
page 46).
Malfunction
Electrical consumers
switched off
The consumer battery has insufficient
voltage and can no longer supply the con-
venience functions such as seat ventila-
tion*.
The electrical consumers will come back
online as soon as on-board voltage is suf-
ficient.
(
Backrest, right rear
not locked
The rear seat backrest is not engaged.
Adjust the rear seat backrest until it is
fully engaged in position.
Backrest, left rear
not locked
The rear seat backrest is not engaged.
Adjust the rear seat backrest until it is
fully engaged in position.
Page 382 of 506

380 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause
Possible solution
2
Brake wear
Visit workshop
The brake pads have reached their wear
limit.
Brake pad thickness must be visually
inspected at the intervals specified in
the Maintenance Booklet.
Have the brake pads replaced as soon
as possible.
T
Reduced braking power
Depress brake
pedal fully
The SBC brake system is in emergency
operation mode. Considerably greater
brake pedal force is required and the
stopping distance is increased.
The maximum speed is limited to 55 mph
(90 km / h).
Do not drive any further.
Stop the vehicle and notify an autho-
rized Mercedes-Benz Center.
Prevent the vehicle from rolling away
by blocking the wheels with wheel
chocks or other sizable objects.
Call for Roadside Assistance.
(USA only);(Canada only)3
Reduced braking power
Start engine
The battery has insufficient voltage and
cannot supply sufficient power to the
SBC brake system.
Start the engine.
The message disappears when suffi-
cient voltage is available.
Page 383 of 506

381 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
(USA only);(Canada only)3
Reduced braking power
Visit workshop
The SBC brake system is in emergency
operation mode. Considerable brake ped-
al force is required and the stopping dis-
tance is increased.
Continue driving with added caution.
Adjust driving to be consistent with
reduced braking responsiveness.
Visit an authorized Mercedes-Benz
Center as soon as possible.
Service brake
Visit workshop
There are malfunctions, but the SBC
brake system is operating normally.
Visit an authorized Mercedes-Benz
Center as soon as possible.
Brake overheated
Drive carefully
The brake system is overheated due to an
excessive load on the brakes.
Relieve the load on the brake system.
Drive more smoothly and think ahead
to avoid unnecessary braking.
When driving down slopes, shift into a
lower gear to use the engine’s braking
power (
page 176).
Cautiously continue driving so that
the air stream will cool down the
brakes.
Release
parking brake
You are driving with the parking brake
set.
Release the parking brake
(page 48).
Page 384 of 506

382 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause
Possible solution
(USA only);(Canada only)3
Brake fluid
Visit workshop
There is insufficient brake fluid in the
reservoir.
Risk of accident! Stop the vehicle and
notify an authorized Mercedes-Benz
Center. Do not add brake fluid! This
will not solve the problem.
Warning!
G
Driving while these messages are displayed
can result in an accident. Have your brake
system checked immediately.
If there is a malfunction in the SBC brake
system, we recommend that the vehicle be
transported with all wheels off the ground
using flatbed or appropriate wheel lift/dolly
equipment.
A tow bar must be used if circumstances do
not permit the use of the recommended
towing methods and the vehicle requires
towing with all four wheels on the ground.
Towing the vehicle with all four wheels on
the ground is only permissible for distances
u p t o 3 0 m i l e s ( 5 0 k m ) a n d a t a s p e e d n o t t o
exceed 30 mph (50 km / h). For more infor-
mation, refer to “Towing the vehicle”
(page 439).
If the SBC brake system enters its emergen-
cy operation mode, the driver must apply
significantly greater brake pedal pressure
and depress the pedal much further than
normal to obtain braking effect. If neces-
sary, apply full pressure to the brake pedal.
Brakes may only be applied to the front
wheels. Stopping distance is increased!
Do not add brake fluid before checking the
brake system. Overfilling the brake fluid res-
ervoir 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
inspected by a qualified technician at
the intervals specified in the
Maintenance Booklet.
Page 436 of 506

434 Practical hintsBatteries
Disconnecting the battery
Depress parking brake firmly or move
gear selector lever to positionP.
Turn off all electrical consumers.
Remove SmartKey from starter switch.
Vehicles with KEYLESS-GO*:
Press the start/stop button until
the engine shuts off.
Open the driver’s door.
Open the trunk.
!Never loosen or detach battery termi-
nal clamps while the engine is running
or the SmartKey is in the starter switch.
Otherwise the alternator and other
electronic components could be se-
verely damaged.
Have the battery checked regularly by
an authorized Mercedes-Benz Center.
Refer to Maintenance Booklet for main-
tenance intervals or contact your au-
thorized Mercedes-Benz Center for
further information.Warning!
G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof battery only to avoid the risk
of acid burns in the event of an accident.
Warning!
G
The SBC brake system requires electrical
power to operate.
A malfunction in the vehicle’s power supply
or electrical system may impair brake sys-
tem operation and switch it into its emer-
gency operation mode. The same applies if
battery is disconnected. To brake, the driver
must then apply significantly greater brake
pedal pressure and depress the pedal much
further to obtain the expected braking ef-
fect. If necessary, apply full pressure to the
brake pedal. Brakes may only be applied to
the front wheels. Stopping distance is in-
creased! Adjust your driving style according-
ly. For more information, refer to “SBC brake
system” (
page 90).
Warning!
G
With a disconnected battery
you will no longer be able to turn the
SmartKey in the starter switch and
pressing the KEYLESS-GO* start/stop
button on the gear selector lever will
have no effect
the gear selector lever will remain
locked in positionP
Page 442 of 506

440 Practical hintsTowing the vehicle
!
To be certain to avoid a possibility of
damage to the drive train, however, we
recommend the drive shaft be discon-
nected at the rear axle drive flange (ve-
hicles with 4MATIC: disconnected at
the front and rear axle drive flanges) for
any towing beyond a short tow to a
nearby garage.
Warning!
G
If circumstances require towing the vehicle
with all wheels on the ground, always tow
with a tow bar if:
the engine will not run
there is a malfunction in the SBC brake
system
there is a malfunction in the power sup-
ply or in the vehicle’s electrical system
as that will be necessary to adequately con-
trol the towed vehicle.
Prior to towing the vehicle with all wheels on
the ground, make certain that the SmartKey
is in starter switch position2.
If the SmartKey is left in the starter switch
position0 for an extended period of time, it
can no longer be turned in the switch. In this
case, the steering is locked. To unlock, re-
move SmartKey from starter switch and re-
insert.
Warning!
G
The brake system requires electrical power
to operate.
A malfunction in the vehicle’s power supply
or electrical system may impair brake sys-
tem operation and switch it into its emer-
gency operation mode. To brake, the driver
must then apply significantly greater brake
pedal pressure and depress the pedal much
further to obtain the expected braking ef-
fect. If necessary, apply full pressure to the
brake pedal. Brakes may only be applied to
the front wheels. Stopping distance is in-
creased! Adapt your driving style according-
ly. For more information, refer to “SBC brake
system” (
page 90).
With the engine not running, there is no
power assistance for the steering system. In
this case, it is important to keep in mind that
a considerably higher degree of effort is nec-
essary to steer the vehicle. Adapt your driv-
ing accordingly.