2008 MERCEDES-BENZ ML320 malfunction

426 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
Tire Pressure Monitor
InoperativeThe TPMS or Advanced TPMS* is
malfunctioning.Have the TPMS or Advanced TPMS* checked by an
authorized Mercedes-Benz Light Truck Center.
Tire Pressure Monitor
Inoperative
No Wheel SensorsThere are wheels without appropriate wheel
sensors mounted (e.g. winter tires).Have the TPMS or Advanced TPMS* checked by an
authorized Mercedes-Benz Light Truck Center.
Have the wheel sensors installed by an authorized
Mercedes-Benz Light Truck Center.
Tire Pressure Monitor
Wheel Sensor MissingVehicles with Advanced TPMS*:
One or more sensors are defect (e.g.
battery is empty).
The respective tire is indicated by
- - -
instead of the tire inflation pressure in the
multifunction display.
Have the Advanced TPMS* checked by an autho-
rized Mercedes-Benz Light Truck Center.
Have the wheel sensors installed by an authorized
Mercedes-Benz Light Truck Center.
Vehicles with Advanced TPMS*:
One or more wheels without appropriate
wheel sensors mounted (e.g. spare tire).
The respective tire is indicated by
- - -
instead of the tire inflation pressure in the
multifunction display.
Have the Advanced TPMS* checked by an autho-
rized Mercedes-Benz Light Truck Center.
Have the wheel sensors installed by an authorized
Mercedes-Benz Light Truck Center.
Tire Pressure Monitor
Currently UnavailableThe TPMS or Advanced TPMS* is unable to
monitor the tire pressure due to a nearby
radio interference source.As soon as the causes of the malfunction have been
removed, the TPMS or Advanced TPMS* automati-
cally becomes active again after a few minutes
driving.

427 Practical hints
What to do if …
Symbol messages
Display symbolDisplay messagePossible cause/consequencePossible solution
ò Replace air filter.The air filter is clogged.Have the air filter checked by an authorized
Mercedes-Benz Light Truck Center.
#The battery is no longer charging.
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 dis-
tance is increased.
Stop the vehicle in a safe location or as soon as
it is safe to do so.
Apply the parking brake (page 65).
 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:
Drive immediately to the nearest authorized
Mercedes-Benz Light Truck Center. Adjust
driving to be consistent with reduced braking
responsiveness.

428 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
#Battery / Alternator
Stop VehicleThe battery is defective.Stop the vehicle in a safe location or as
soon as it is safe to do so.
Apply the parking brake (page 65).
Do not continue to drive.
Contact an authorized Mercedes-Benz
Light Truck Center.
{InoperativeDownhill Speed Regulation is
malfunctioning.Have the Downhill Speed Regulation
checked by an authorized Mercedes-Benz
Light Truck Center.
2Brake WearThe brake pads have reached
their wear limit.Have the brake pads replaced as soon as
possible.
!Brake pad thickness must be visually in-
spected by a qualified technician at the intervals
specified in the Maintenance Booklet.

431 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
Ï Coolant Level
Stop car, switch engine off.The coolant is too hot.
Among other possible causes
(the cooling fan could be
malfunctioning), the poly-V-belt
could be broken.Stop the vehicle in safe location or as
soon as it safe to do so.
Apply the parking brake (page 65).
Turn off the engine.
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:
Do not continue to drive the vehicle with
this message displayed. Doing so could
result in serious engine damage that is
not covered by the Mercedes-Benz Limit-
ed Warranty.
(Continued on next page)

438 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
. 3rd Brake LampThe high mounted brake lamp is
malfunctioning. This message
will only appear if a critical num-
ber of LEDs have stopped work-
ing.Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
Active Headlamps
InoperativeThe active Bi-Xenon* headlamp
system is malfunctioning.Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
AUTO Light
InoperativeThe light sensor is malfunction-
ing. The headlamps switch on
automatically.Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
To switch off the headlamps
(U. S. vehicles only):
In the control system, set lamp operation
to manual mode (
page 136).
Switch off the headlamps using the
exterior lamp switch (
page 135).
Brake Lamp
LeftThe left brake lamp is malfunc-
tioning. A substitute bulb is
being used.Replace the bulb as soon as possible
(
page 471).
Brake Lamp
RightThe right brake lamp is malfunc-
tioning. A substitute bulb is
being used.Replace the bulb as soon as possible
(
page 471).

439 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
. Cornering Lamp
LeftThe left corner-illuminating front fog lamp
is malfunctioning.Replace the bulb as soon as possible
(
page 469).
Cornering Lamp
RightThe right corner-illuminating front fog
lamp is malfunctioning.Replace the bulb as soon as possible
(
page 469).
Front Foglamp
LeftThe left front fog lamp is malfunctioning.Replace the bulb as soon as possible
(
page 469).
Front Foglamp
RightThe right front fog lamp is malfunctioning.Replace the bulb as soon as possible
(
page 469).
High Beam
LeftThe left high beam lamp is
malfunctioning.Halogen headlamp:
Replace the bulb as soon as possible
(
page 467).
Bi-Xenon* headlamp:
Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
High Beam
RightThe right high beam lamp is
malfunctioning.Halogen headlamp:
Replace the bulb as soon as possible
(
page 467).
Bi-Xenon* headlamp:
Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.

440 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
. License Plate Lamp
LeftThe left license plate lamp is
malfunctioning.Replace the bulb as soon as possible
(
page 473).
License Plate Lamp
RightThe right license plate lamp is
malfunctioning.Replace the bulb as soon as possible
(
page 473).
Low Beam
LeftThe left low beam lamp is
malfunctioning.Halogen headlamp:
Replace the bulb as soon as possible
(
page 466).
Bi-Xenon* headlamp:
Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
Low Beam
RightThe right low beam lamp is
malfunctioning.Halogen headlamp:
Replace the bulb as soon as possible
(
page 466).
Bi-Xenon* headlamp:
Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.

441 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
. Marker Lamp
Front LeftThe left front side marker lamp is
malfunctioning.Replace the bulb as soon as possible
(
page 469).
Marker Lamp
Front RightThe right front side marker lamp
is malfunctioning.Replace the bulb as soon as possible
(
page 469).
Parking Lamp
Front LeftThe front left parking lamp is
malfunctioning. A substitute
bulb is being used.Replace the bulb as soon as possible
(
page 468).
Parking Lamp
Front RightThe right front parking lamp is
malfunctioning. A substitute
bulb is being used.Replace the bulb as soon as possible
(
page 468).
Foglamp
Rear LeftThe left rear fog lamp is malfunc-
tioning.Replace the bulb as soon as possible
(
page 471).
Reverse Lamp
LeftThe left backup lamp is
malfunctioning.Replace the bulb as soon as possible
(
page 471).
Reverse Lamp
RightThe right backup lamp is
malfunctioning.Replace the bulb as soon as possible
(
page 471).