Page 388 of 522
387 Practical hints
What to do if …
Problem
Possible cause/consequence
Suggested solution
l
Only vehicles with Distronic*:
The red distance warning lamp
comes on while driving.
You are too close to the vehicle in front of you
to maintain selected speed.
Apply the brakes immediately to in-
crease the following distance.
Only vehicles with Distronic*:
The red distance warning lamp
comes on while driving and you
hear a warning chime sound.
You are gaining too rapidly on the vehicle
ahead of you.
The distance warning system has recog-
nized a stationary obstacle on your prob-
able line of travel.
Apply the brakes immediately.
Carefully observe the traffic situation.
You may need to brake or maneuver
to avoid hitting an obstacle.
A
The yellow fuel tank reserve
warning lamp comes on while
driving.
The fuel level has gone below the reserve
mark.
Refuel at the next gas station
(page 321).
Page 399 of 522

398 Practical hintsWhat to do if …Text messagesDisplay message
Possible cause/consequence
Possible solution
ABS
ABS, ESP
inoperative
See Operator’s Man.
ABS, ESP
® as well as PRE-SAFE
®
have switched off due to a malfunc-
tion.
BAS is also switched off.
The brake system is still functioning
normally but without the ABS, BAS,
ESP
® and PRE-SAFE
® 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.
ABS, ESP
unavailable
See Operator’s Man.
ABS, ESP
® as well as PRE-SAFE
®
were deactivated because of insuffi-
cient power supply. The charging
voltage has fallen below 10 volts.
The brake system still functions nor-
mally but without the ABS, BAS,
ESP
® and PRE-SAFE
® available.
When the voltage is above this value again, the
ABS, ESP
® and PRE-SAFE
® are operational
again and the message should disappear.
If the message does not disappear:
Have the system checked at an authorized
Mercedes-Benz Center as soon as possible.
Page 403 of 522
402 Practical hintsWhat to do if …Display message
Possible cause/consequence
Possible solution
ESP
inoperative
See Operator’s Man.
The ESP
® as well as BAS and
PRE-SAFE® have detected a mal-
function and switched off.
The ABS may not be operational.
The brake system is still functioning
normally but without the ABS, BAS,
ESP
® and PRE-SAFE
® 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.
Page 404 of 522

403 Practical hints
What to do if …
Display message
Possible cause/consequence
Possible solution
(USA only)Front passenger
airbag enabled
See Operator’s Manual
Front passenger front air bag is
activated while driving even
though a child, small individual, or
object below the system’s weight
threshold is on the front passen-
ger seat, or the front passenger
seat is empty. Objects on the seat
or forces acting on the seat may
make the system sense supple-
mental weight.
Stop the vehicle in a safe location as soon as possible and check the
front passenger seat for the following:
Apply the parking brake.
Switch off the ignition (
page 38).
Open the front passenger door.
Remove child and child restraint from front passenger seat and
properly secure the child in rear seat employing the child restraint
if necessary.
Remove any other items from on and around the front passenger
seat and make sure the storage pocket on the back of the front pas-
senger seat is empty.
Make sure that no objects which apply forces to the seat are
present (e.g. objects such as books, briefcases etc. lodged behind
or around the seat, head restraints pushing against roof etc.). The
system may recognize such forces as supplemental weight and
sense that an occupant on the front passenger seat is of a greater
weight than actually present.
Keep the seat unoccupied, close the front passenger door and turn
on the ignition (
page 38).
(Continued on next page)
Page 406 of 522

405 Practical hints
What to do if …
Display message
Possible cause/consequence
Possible solution
(USA only)Front passenger
airbag disabled
See Operator’s Manual
Front passenger front air bag is
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 front
passenger seat for the following:
Apply the parking brake.
Switch off the ignition (
page 38).
Have the front passenger vacate the seat and exit the vehicle.
Adjust the seat in a height position (
page 43).
Make sure that no objects which apply forces to the seat are present
(e.g. objects such as books, briefcases etc. lodged underneath, be-
hind or around the seat). Such forces may cause the system to sense
that an occupant of a lesser weight than actually present is on the
front passenger seat.
Keep the seat unoccupied, close the front passenger door and turn on
the ignition (
page 38).
(Continued on next page)
Page 408 of 522

407 Practical hints
What to do if …
Display
Possible cause/consequence
Possible solution
P
Gear selector lever
in Park position
You have tried to start the engine with the
KEYLESS-GO* start/stop button with the
gear selector lever not in positionP.
Place the gear selector lever in
positionP.
You have tried to turn off the engine with the
KEYLESS-GO* start/stop button with the
gear selector lever not in positionP.
P/N
Shift gear select. lever
to Neutral or Park
You have tried to start the engine with the
KEYLESS-GO* start/stop button while the
gear selector lever was in positionR orD.
Place the gear selector lever in positionP
orN. Make sure the brake pedal is de-
pressed.
PRE-SAFE
inoperative
See Operator’s Man.
PRE-SAFE
® itself has failed. All other occu-
pant safety systems, such as the air bags, are
still available.
Visit an authorized Mercedes-Benz Cen-
ter as soon as possible.
If ESP
® and PRE-SAFE
® malfunction messag-
es are displayed simultaneously, PRE-SAFE
®
has been deactivated as a result of these
malfunctions. All other occupant safety sys-
tems, such as the air bags, are still available.
Page 411 of 522
410 Practical hintsWhat to do if …Display message
Possible cause/consequence
Possible solution
Tire pressure
monitor
currently unavailable
The Advanced 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 Advanced TPMS* automatically becomes ac-
tive again after a few minutes driving.
Warning!
G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle.
You may lose control of the vehicle. Contin-
ued driving with a flat tire will cause exces-
sive heat build-up and possibly a fire.
Page 412 of 522

411 Practical hints
What to do if …
Symbol messagesDisplay symbol
Display message
Possible cause/consequence
Possible solution
#
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.
There is a malfunction in the electronic
system.
Have the system checked at an autho-
rized Mercedes-Benz Center as soon
as possible.