Page 383 of 539

382 Practical hintsWhat to do if …Lamps in instrument clusterGeneral information:
If any of the following lamps in the instru-
ment cluster fails to come on during thebulb self-check when switching on the igni-
tion, have the respective bulb checked and
replaced if necessary.Problem
Possible cause
Suggested solution
-
The yellow ABS indicator lamp
comes on while the engine is
running.
ABS has detected a malfunction and has
switched off. The BAS, ESP
®, and 4-ETS are
also switched off (see messages in multifunc-
tion display).
The brake system is still functioning normally
but without the ABS available.
If the ABS control unit is malfunctioning,
other systems such as the navigation
system* or the automatic transmission may
also be malfunctioning.
Continue driving with added caution.
Wheels may lock during hard braking,
reducing steering capability.
Read and observe messages in the
multifunction display (
page 395).
Have the system checked at an
authorized Mercedes-Benz Light
Truck Center as soon as possible.
Failure to follow these instructions
increases the risk of an accident.
The charging voltage has fallen below
ten volts. The ABS has switched off.
The battery might not be charged sufficiently.
Switch off electrical consumers that
are currently not needed, e.g. seat
heating*.
If necessary, have the generator
(alternator) and the battery checked.
When the voltage is above this value
again, the ABS is operational again.
Page 386 of 539
385 Practical hints
What to do if …
Problem
Possible cause
Suggested solution
?
(USA only)
±
(Canada only)
The yellow engine malfunction
indicator lamp comes on while
driving.
There is a malfunction in:
The fuel management
system
The ignition system
The emission control
system
Systems which affect
emissions
Such malfunctions may result
in excessive emissions values
and may switch the engine to
its limp-home (emergency op-
eration) mode (
page 192).
Have the vehicle checked as soon as
possible by an authorized
Mercedes-Benz Light Truck Center.
An on-board diagnostic connector is
used by the service station to link the
vehicle to the shop diagnostics
system. It allows the accurate identifi-
cation of system malfunctions through
the readout of diagnostic trouble
codes. It is located in the front left area
of the footwell next to the parking
brake pedal.
Page 398 of 539
397 Practical hints
What to do if …
Text messagesDisplay 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 deactivated.
The brake system is still functioning
normally but without the ABS avail-
able.
Continue driving with added caution.
Wheels may lock during hard braking,
reducing steering capability.
Have the system checked at an authorized
Mercedes-Benz Light Truck Center as soon
as possible.
Failure to follow these instructions increases
the risk of accident.
Display malfunction
Visit workshop
The ABS or the ABS display is mal-
functioning.
Continue driving with added caution.
Wheels may lock during hard braking, re-
ducing steering capability
Have the system checked at an authorized
Mercedes-Benz Light Truck Center as soon
as possible.
Failure to follow these instructions increases
the risk of accident.
Page 399 of 539

398 Practical hintsWhat to do if …Display message
Possible cause
Possible solution
ABS
unavailable
See Operator’s Manual
The ABS was deactivated because of
insufficient power supply. The charg-
ing voltage has fallen below ten
volts.
The brake system is still functioning
normally but without the ABS
available.
Switch off electrical consumers that are
currently not needed, e.g. seat heating*.
If necessary, have the generator
(alternator) and the battery checked.
When the voltage is above this value again, the
ABS is operational again and the message in
the multifunction display should disappear.
Battery
protection
Convenience functs.
Temporarily
Unavailable
The battery has insufficient voltage
and can no longer supply conve-
nience functions such as the rear
window defroster.
As soon as the on-board voltage is sufficient,
the consumers will switch on again.
Please note:
Convenience Functions
Available again
On-board voltage is sufficient; the
consumers will switch on again.
Cruise
control
Drive to workshop
Cruise control is malfunctioning.
Have cruise control checked by an
authorized Mercedes-Benz Light Truck
Center.
DSR
Malfunction
Downhill Speed Regulation is
malfunctioning.
Have the Downhill Speed Regulation
checked by an authorized Mercedes-Benz
Light Truck Center.
Page 400 of 539

399 Practical hints
What to do if …
Display message
Possible cause
Possible solution
ESP
unavailable
See Operator’s Manual
In addition, the yellow ESP
® warning
lampv comes on.
The ESP
® is deactivated because of
a malfunction or interrupted power
supply.
Continue driving with added caution.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Failure to follow these instructions increases
the risk of accident.
If the yellow ESP
® warning
lampv flashes while driving and
this message appears, the electron-
ic traction system has switched off
to prevent overheating of the drive
wheel brakes.
As soon as the brakes have cooled off, the
electronic traction system switches on again.
The message in the multifunction display disap-
pears and the ESP
® warning lampv go out.
The self-diagnosis has not yet been
completed.
The display will clear after driving a short dis-
tance at a vehicle speed of above 12 mph
(20 km/h).
Malfunction
Visit workshop
In addition, the yellow ESP
® warning
lampv comes on.
The ESP
® has detected a malfunc-
tion and switched off.
The ABS may still be operational.
Continue driving with added caution.
Have the system checked at an authorized
Mercedes-Benz Light Truck Center as soon
as possible.
Failure to follow these instructions increases
the risk of an accident.
Page 408 of 539

407 Practical hints
What to do if …
Symbol messagesDisplay symbol
Display messages
Possible cause
Possible solution
#
Undervoltage
Switch off consumers
The battery has insufficient volt-
age.
Turn off unnecessary electrical
consumers.
malfunction
Visit workshop
The battery was charged with a
battery charger or jump started.
Have the battery checked at a service
station.
Battery/Alternator
Stop vehicle
The battery is no longer charg-
ing.
Possible causes:
alternator malfunctioning
broken poly-V-belt
Do not forget that the brake sys-
tem requires electrical energy
and may be operating with re-
stricted capability. Considerably
greater brake pedal force is
required and the stopping dis-
tance is increased.
Stop immediately 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. Notify an authorized
Mercedes-Benz Light Truck Center.
If it is intact:
Drive immediately to the nearest autho-
rized Mercedes-Benz Light Truck Center.
Adjust driving to be consistent with re-
duced braking responsiveness.
Page 445 of 539

444 Practical hintsReplacing bulbsRear lamps Notes on bulb replacement
Only use 12 volt bulbs of the same type
and with the specified watt rating.
Switch lights off before changing a bulb
to prevent short circuits.
Always use a clean lint-free cloth when
handling bulbs.
Your hands should be dry and free of oil
and grease.
If the newly installed bulb does not
come on, visit an authorized
Mercedes-Benz Light Truck Center.
Lamp
Type
8
High mounted brake
lamp
LED
9
Brake lamp
P21W
a
Backup lamp
P21W
b
Turn signal lamp
PY 21 W
c
Side marker lamp
P21/4W
d
Tail, parking, standing
lamp, rear fog lamp
(only driver’s side)
P21/4W
e
License plate lamps
C5W
Warning!
G
Bulbs and bulb sockets can be very hot.
Allow the lamp to cool down before chang-
ing a bulb.
Keep bulbs out of reach of children.
Halogen lamps contain pressurized gas.
A bulb can explode if you:
touch or move it when hot
drop the bulb
scratch the bulb
Wear eye and hand protection.
Because of high voltage in Xenon lamps, it is
dangerous to replace the bulb or repair the
lamp and its components. We recommend
that you have such work done by a qualified
technician.
Page 446 of 539
445 Practical hints
Replacing bulbs
Have the LEDs and bulbs for the following
lamps replaced by an authorized
Mercedes-Benz Light Truck Center:
Additional turn signals in the exterior
rear view mirrors
Bi-Xenon lamps*
Front fog lamps (vehicles with sport
package*)
High mounted brake lamp
Replacing bulbs for front lamps
Before you start to replace a bulb for a
front lamp, do the following first:
Turn the exterior lamp switch to
positionM (
page 138).
Open the hood (
page 326).
1Housing cover for low beam halogen or
Bi-Xenon* headlamp
2Housing cover for high beam halogen
bulb (vehicles with halogen bulbs: high
beam and high beam flasher; vehicles
with Bi-Xenon* headlamps: high beam
flasher only)
3Bulb socket for parking and standing
lamp bulb
4Bulb socket for turn signal lamp bulb
5Bulb socket for side marker lamp bulb