Page 405 of 561

404 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
ignition, have the respective bulb checked
and replaced if necessary.Problem
Possible cause/consequence
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 416).
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
10 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 battery checked.
When the voltage is above this value
again, the ABS is operational again.
Page 406 of 561

405 Practical hints
What to do if …
Problem
Possible cause/conse-
quence
Suggested solution
;
(USA only)
3
(Canada only)
The red brake warning lamp
comes on while driving and
you hear a warning sound.
You are driving with the
parking brake set.
Release the parking brake
(page 56).
The ESP
® control unit may be
malfunctioning.
The driving safety systems
may not be available.
Continue driving with added caution.
Wheels may lock during hard braking,
reducing steering capability.
Read and observe messages in the
multifunction display (
page 416).
The red brake warning lamp
comes on while driving.
There is insufficient brake fluid
in the reservoir.
Risk of accident! Carefully stop the
vehicle in a safe location or as soon as
it is safe to do so and notify an autho-
rized Mercedes-Benz Light Truck Cen-
ter. 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 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 407 of 561
406 Practical hintsWhat to do if …Problem
Possible cause/conse-
quence
Suggested solution
;
(USA only)
3
(Canada only)
-
v
The red brake warning lamp
comes on while driving. In
addition, the yellow ABS mal-
function indicator lamp, and
the yellow ESP
® warning lamp
come on and a warning will
sound.
A malfunction in the Electronic
Brake Proportioning
(page 102) was detected.
Have the system checked at an autho-
rized Mercedes-Benz Light Truck
Center as soon as possible.
Failure to follow these instructions
increases the risk of an accident.
Page 408 of 561

407 Practical hints
What to do if …
Problem
Possible cause/conse-
quence
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
operation) mode.
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.
iSome states may by law require you to
visit a workshop immediately as soon
as the engine malfunction indicator
lamp comes on. Check local require-
ments.
Page 419 of 561
418 Practical hintsWhat to do if …Text messagesDisplay message
Possible cause/consequence
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 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 an 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,
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 an accident.
Page 420 of 561

419 Practical hints
What to do if …
Display message
Possible cause/consequence
Possible solution
ABS
unavailable
See Operator’s Manual
The ABS was deactivated because of
insufficient power supply. The charg-
ing voltage has fallen below 10 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.
Cruise
control
Drive to workshop
Cruise control is malfunctioning.
Have cruise control checked by an
authorized Mercedes-Benz Light Truck
Center.
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 an accident.
Page 421 of 561

420 Practical hintsWhat to do if …Display message
Possible cause/consequence
Possible solution
ESP
unavailable
See Operator’s Manual
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 goes
out.
The self-diagnosis has not yet been
completed yet.
The display will clear after driving a short
distance 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.
Display malfunction
Visit workshop
In addition, the yellow ESP
® warning
lampv comes on.
The ESP
® or the ESP
® display is
malfunctioning.
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 an accident.
Page 422 of 561

421 Practical hints
What to do if …
Display message
Possible cause/consequence
Possible solution
P
Gear selector lever
in Park
You have started the engine or
switched on the ignition with
KEYLESS-GO* and opened the
driver’s door with the automatic
transmission not set to positionP.
Set the automatic transmission to
positionP.
or
Close the driver’s door
Gear selector lever
in Neutral or Park
You have attempted to start the
engine with the KEYLESS-GO*
start/stop button while the auto-
matic transmission was set to
positionR orD.
Set the automatic transmission to
positionP orN.
Make sure the brake pedal is depressed
when attempting to start the engine with
the KEYLESS-GO* start/stop button.
PRE-SAFE
unavailable
See Operator’s Manual
If ESP
® and PRE-SAFE
®* malfunc-
tion messages are displayed simul-
taneously, PRE-SAFE®* has been
deactivated as a result of these mal-
functions. All other occupant safety
systems, such as the air bags are
still available.
Visit an authorizes Mercedes-Benz Light
Truck Center as soon as possible.
PRE-SAFE
®* itself has failed. All oth-
er occupant safety systems, such as
the air bags are still available.
Visit an authorizes Mercedes-Benz Light
Truck Center as soon as possible.