check engine MERCEDES-BENZ R320CDI 2007 R171 Owner's Guide

409 Operation
Maintenance
Calling up the maintenance service
indicator display
You can call up the maintenance service
indicator display at any time to check
when the next maintenance service is due.
Switch on the ignition (page 39).
The standard display of the control sys-
tem appears (
page 166).
Press button èorÿon the
multifunction steering wheel
repeatedly until the standard display
appears in the multifunction display
(
page 166).
Press button k or j on the
multifunction steering wheel until the
maintenance service indicator display
with the service symbol 9 and the
service deadline appears in the multi-
function display.Resetting the maintenance service
indicator
In the event that the maintenance service
on your vehicle is not carried out by an
authorized Mercedes-Benz Light Truck
Center, you can have the maintenance
service indicator reset. The automotive
maintenance facility carrying out the
maintenance service will find the informa-
tion for resetting the maintenance service
indicator in the maintenance-relevant
literature for your vehicle. Such literature
is available either from either an
authorized Mercedes-Benz Light Truck
Center or directly from Mercedes-Benz.
iThe menu overview can be found on
(
page 162).
iIf the battery is disconnected, the days of
disconnection will not be included in the count
shown by the maintenance service indicator. To
arrive at the true maintenance service deadline,
you will need to subtract these days from the
days shown in the maintenance service indicator
message or maintenance service indicator
display.
iIf the maintenance service indicator was in-
advertently reset, have an authorized
Mercedes-Benz Light Truck Center correct it.
Only reset if the proper maintenance service has
been performed. Resetting the system without
performing the proper service as called for by
the maintenance service indicator will result in
engine damage and/or other vehicle damage not
covered by the Mercedes-Benz Limited
Warranty.

420 Practical hints
What 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.
ProblemPossible cause/consequenceSuggested 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®, EBP, and 4-ETS
are also switched off (see messages in multi-
function 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 433).
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.When the voltage is above this value
again, the ABS is operational again and
the ABS indicator lamp should go out.
If the ABS indicator lamp does not go out:
Have the generator (alternator) and
the battery checked.

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.

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.

424 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.A loss of pressure has been
detected in the fuel system.
The fuel cap may not be closed
properly or the fuel system
may be leaky.Check the fuel cap (page 360).
If it is not closed properly:
Close the fuel cap.
If it is closed properly:
Have the fuel system checked by an
authorized Mercedes-Benz Light Truck
Center.
Your fuel tank is empty.After refueling start, turn off and
restart the engine three or four times in
succession.
The limp-home mode is canceled. You do
not need to have your vehicle checked.

425 Practical hints
What to do if …
ProblemPossible cause/consequenceSuggested solution
vThe yellow ESP® warning lamp
comes on while the engine is
running.The ESP® has been switched of with the ESP®
switch or has switched off due to a
malfunction.
Risk of accident!
Adapt your speed and driving to the prevail-
ing road, weather, and traffic conditions.Switch the ESP® back on
(
page 105).
If the ESP
® cannot be switched back on:
Continue driving with added caution.
Observe additional messages in the
multifunction display that may
appear.
Have the system checked at an autho-
rized Mercedes-Benz Light Truck
Center as soon as possible.
vThe yellow ESP® warning lamp
flashes while driving.The ESP® or traction control has come into
operation because of detected traction loss
of at least one tire.When driving off, apply as little throt-
tle as possible.
While driving, ease up on the acceler-
ator.
Adapt your speed and driving to the
prevailing road and weather condi-
tions.
Do not deactivate the ESP®.
Exceptions: (
page 104)
Failure to follow these instructions
increases the risk of an accident.

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.

454 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
;(USA only)
3(Canada only)
Check
brake fluid levelThere is insufficient brake fluid
in the reservoir.Risk of accident! Carefully stop the vehi-
cle 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 flu-
id! This will not solve the problem.
Warning!G
Driving with the message Check brake
fluid level
displayed can result in an ac-
cident. Have your brake system checked im-
mediately. Do not add brake fluid before
checking the brake system. Overfilling the
brake fluid reservoir can result in spilling
brake fluid on hot engine parts and the
brake fluid catching fire. You could 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.

455 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
•Coolant level
Stop car, switch engine
offThe 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 a safe location or
as soon as it is safe to do so.
Turn off the engine.
Apply the parking brake (page 66).
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:
Wait for the message to disappear
before restarting the engine.
Doing otherwise could result in seri-
ous engine damage that is not
covered by the Mercedes-Benz
Limited Warranty.
(Continued on next page)

457 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
B Top up coolant
See Oper. ManualThe coolant level is too low.Add coolant (page 370).
If you have to add coolant frequently,
have the cooling system checked by an
authorized Mercedes-Benz Light Truck
Center.
Warning!G
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts. You could be seriously burned.
!Do not ignore the low engine coolant level
warning. Extended driving with the message and
symbol displayed may cause serious engine
damage not covered by the Mercedes-Benz
Limited Warranty.
Do not drive without sufficient amount of coolant
in the cooling system. The engine will overheat,
causing major engine damage.