Page 397 of 521
396 Practical hintsWhat to do if …Display messages
Possible cause/con-
sequence
Possible solution
Front passenger
airbag
deactivated
See Operator’s Manual
Monitor the 75 indicator lamp on the center console (
page 27) and the
multifunction display in the instrument cluster (
page 26) for the following:
With the seat unoccupied and the ignition turned on,
the 75 indicator lamp on the center console should illuminate and re-
main illuminated, indicating that the OCS (
page 81) has deactivated the front
passenger front air bag.
the message
Front passenger airbag activated See Operator’s Manual
or
the message
Front passenger airbag deactivated See Operator’s Manual
should not appear in the multifunction display at any time the seat is unoccu-
pied. Wait at last 60 seconds for the system to complete the necessary check
cycles and to make sure neither message appears in the multifunction display.
If above conditions are met, you can occupy the front passenger seat again. De-
pending on the front passenger classification sensed by the OCS (
page 81), the
75 indicator lamp will remain illuminated or go out.
If above conditions are not met, the system is not working properly. Have the sys-
tem checked as soon as possible by an authorized Mercedes-Benz Center.
Warning!
G
If the 75 indicator lamp remains
illuminated with an adult occupant on the
front passenger seat even after performing
the above corrective steps, do not have any
passenger use the front passenger seat until
the system has been repaired.
Page 398 of 521
397 Practical hints
What to do if …
Display message
Possible cause/consequence
Possible solution
Tire pres. monitor
inoperative
The TPMS* is malfunctioning.
Have the TPMS* checked by an authorized
Mercedes-Benz Center.
Tire pres. monitor
inoperative
No wheel sensors
There are wheels without wheel sensors
mounted (e.g. winter tires).
Have the TPMS* checked by an authorized
Mercedes-Benz Center.
Have the wheel sensors installed by an authorized
Mercedes-Benz Center.
Tire pres. monitor
Wheel sensor missing
One or more sensors malfunction (e.g. bat-
tery in one or more wheel sensor is empty).
One or more wheels without wheel sensors
mounted (e.g. spare tire).
Have the TPMS* checked by an authorized
Mercedes-Benz Center.
Have the wheel sensors installed by an authorized
Mercedes-Benz Center.
The tire pressure for the respective tire is shown in the
multifunction display.
Tire pres. monitor
currently unavailable
The TPMS* is unable to monitor the tire
pressure due to
a nearby radio interference source.
excessive wheel sensor temperatures.
As soon as the causes for the malfunction are no longer
present, the TPMS* automatically becomes active again
after a few minutes driving.
Page 399 of 521
398 Practical hintsWhat to do if …Symbol messagesDisplay symbol
Display messages
Possible cause/consequence
Possible solution
#
Low voltage
Switch off
consumers
The battery has insufficient voltage.
Turn off unnecessary electrical con-
sumers.
Visit workshop
The battery was charged with a battery
charger or jump started.
Have the battery checked at a service
station.
The battery is no longer charging.
Possible causes:
alternator malfunctioning
broken poly-V-belt
Do not forget that the brake system re-
quires electrical energy and may be oper-
ating with restricted capability.
Considerably greater brake pedal force is
required and the stopping distance is in-
creased.
Stop immediately in a safe location or
as soon as it is safe to do so and
check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise
the engine will overheat due to an in-
operative water pump which may re-
sult in damage to the engine. Notify
an authorized Mercedes-Benz Center.
If it is intact:
Drive immediately to the nearest au-
thorized Mercedes-Benz Center. Ad-
just driving to be consistent with
reduced braking responsiveness.
Page 400 of 521
399 Practical hints
What to do if …
Display symbol
Display messages
Possible cause/consequence
Possible solution
#
Battery/Alternator
Stop vehicle
The battery is malfunctioning.
The electrohydraulic brake system re-
quires electrical energy and therefore has
only limited operation. Considerably
greater brake pedal force is required and
the stopping distance is increased.
Stop the vehicle in a safe location as
soon as it is safe to do so. Adjust driv-
ing to be consistent with reduced
braking responsiveness.
Notify an authorized Mercedes-Benz
Center.
Low voltage
Start engine
The battery has insufficient voltage.
Start the engine (
page 50).
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 401 of 521
400 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause/consequence
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 electrohydraulic brake system is in
emergency operation mode. Consider-
ably 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 as soon as it is safe
to do so and notify an authorized
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
electrohydraulic brake system.
Start the engine (
page 50).
The message disappears when suffi-
cient voltage is available.
!Brake pad thickness must be visually
inspected by a qualified technician at
the intervals specified in the
Maintenance Booklet.
Page 402 of 521
401 Practical hints
What to do if …
Display symbol
Display messages
Possible cause/consequence
Possible solution
(USA only);(Canada only)3
Reduced braking power
Visit workshop
The electrohydraulic brake system is in
emergency operation mode. Consider-
able brake pedal force is required and the
stopping distance 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 electro-
hydraulic brake system is operating nor-
mally.
Visit an authorized Mercedes-Benz
Center as soon as possible.
Brake overheated
Drive on, but with
even greater care
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 190).
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 53).
Page 403 of 521
402 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause/consequence
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 in a
safe location as soon as it is safe to do
so and notify an authorized
Mercedes-Benz Center. Do not add
brake fluid! This will not solve the
problem.
Warning!
G
Driving with the message
Brake fluid
Visit workshop
displayed can result in an
accident. Have your brake system checked
immediately.
If there is a malfunction in the electrohy-
draulic 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 457).
If the electrohydraulic brake system enters
its emergency operation mode, the driver
must apply significantly greater brake pedal
pressure and depress the pedal much fur-
ther than normal to obtain braking effect. If
necessary, apply full pressure to the brake
pedal. Brakes may only be applied to the
front wheels. Stopping distance is in-
creased!
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.
Page 404 of 521
403 Practical hints
What to do if …
Display symbol
Display messages
Possible cause/consequence
Possible solution
ú
(USA only)
±
(Canada only)
Engine
Service
There may be a malfunction in the:
fuel injection system
ignition system (Gasoline engine)
exhaust system
fuel system
Have the measuring system checked
by an authorized Mercedes-Benz
Center.
B
Coolant
Check level
The coolant level is too low.
Add coolant (
page 325).
If you have to add coolant frequently,
have the cooling system checked by
an authorized Mercedes-Benz Center.
Warning!
G
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts. You can be seriously burned.
!Do not ignore the low engine coolant
level warning. Extended driving with
the message and symbol displayed
may cause serious engine damage not
covered by the Mercedes-Benz Limited
Warranty.
Do not drive without sufficient amount
of coolant in the cooling system. The
engine will overheat causing major en-
gine damage.