Page 422 of 570

421 Practical hints
What to do if …
ProblemPossible cause/conse-
quenceSuggested solution
;(USA only)
3(Canada only)
The red brake warning lamp
comes on while driving and an
acoustic warning sounds.You are driving with the
parking brake set.Release the parking brake
(
page 57).
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.
Apply the parking brake (page 66).
Contact an authorized
Mercedes-Benz Light Truck Center.
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 423 of 570
422 Practical hints
What to do if …
ProblemPossible cause/conse-
quenceSuggested 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 an acoustic warn-
ing sounds.
A malfunction in the Electronic
Brake Proportioning
(
page 105) 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 424 of 570

423 Practical hints
What to do if …
ProblemPossible cause/conse-
quenceSuggested 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 requirements.
Page 436 of 570

435 Practical hints
What to do if …
Text messages
Display messagePossible cause/consequencePossible solution
ABSinoperative
See Operator's ManualThe 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 an accident.
unavailable
See Operator’s ManualThe 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.When the voltage is above this value again, the
ABS is operational again and the message in
the multifunction display should disappear.
If the message in the multifunction display
does not disappear:
Have the generator (alternator) and the
battery checked.
Page 437 of 570

436 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
ABSunavailable
See Operator’s ManualIf 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).
Cruise
control and
SPEEDTRONIC
inoperativeThe cruise control is malfunctioning.Have cruise control checked by an
authorized Mercedes-Benz Light Truck
Center.
Cruise
control––– mphYou have attempted to set a
speed while driving below
20 mph (30 km/h).Accelerate to a speed exceeding
20 mph (30 km/h) and set the speed
(
page 266).
The ESP® is switched off.Switch on the ESP® (page 105).
The automatic transmission is set to
position P, R, or N.Set the automatic transmission to
positionD (
page 197).
The vehicle is secured with the
parking brake.Release the parking brake (page 57).
Page 438 of 570
437 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
DISTRONIC––– mphYou have attempted to set a
speed while driving below
20 mph (30 km/h).Accelerate to a speed exceeding
20 mph (30 km/h) and set the speed
(
page 266).
The ESP® is switched off.Switch on the ESP® (page 105).
The automatic transmission is set to
position P, R, or N.Set the automatic transmission to posi-
tion D (
page 197).
The vehicle is secured with the
parking brake.Release the parking brake (page 57).
inoperativeThe Distronic* or the Distronic*
display are malfunctioning.Have the system checked by an
authorized Mercedes-Benz Light Truck
Center.
OverrideYou have accelerated. The
Distronic* has switched off.Stop accelerating.
Page 441 of 570

440 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
Depress brake to
shift out of
ParkYou have tried to shift the automatic
transmission into position D, R or N
using the gear selector lever without
depressing the brake pedal.Depress the brake pedal.
Door Open
Vehicle not in ParkYou have opened the driver’s door
and the automatic transmission is
still in position D, R or N.Before you leave the vehicle, make sure
that the automatic transmission is set to
position P and that the parking brake is
engaged.
Drive to workshop
without
shifting gearsThe automatic transmission cannot
be shifted out of the set position be-
cause of a malfunction.If the automatic transmission is set to
positionD:
Without changing the automatic transmis-
sion from position D, drive to an authorized
Mercedes-Benz Light Truck Center.
If the automatic transmission is set to
positionN, R or P:
Do not drive.
Contact an authorized Mercedes-Benz Light
Truck Center.
Page 452 of 570
451 Practical hints
What to do if …
Symbol messages
Display symbolDisplay messagePossible cause/consequencePossible solution
#The battery is no longer charg-
ing.
Possible causes:
alternator malfunctioning
broken poly-V-belt
Do not forget that the brake
system requires electrical
energy and may be operating
with restricted capability.
Considerably greater brake
pedal force is required and the
stopping distance is increased.
Stop 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
inoperative water pump which may
result in damage to the engine.
Contact an authorized
Mercedes-Benz Light Truck Center.
If it is intact:
Contact an authorized
Mercedes-Benz Light Truck Center
immediately. Adjust driving to be
consistent with reduced braking
responsiveness.