2008 MERCEDES-BENZ GL320 check engine

459 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
PShift to P or N
to start engine.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 but-
ton.
Only shift to P
when vehicle
is at a standstill.You have tried to shift the automat-
ic transmission into positionP us-
ing the gear selector lever although
the vehicle is still in motion.Stop the vehicle.
Apply the parking brake (page 67).
SRSRestraint Sys. Malfunction
Service RequiredThe system is malfunctioning.Drive with added caution to the nearest
authorized Mercedes-Benz Light Truck
Center.
Warning!G
In the event a malfunction of the SRS is indi-
cated as outlined above, the SRS may not be
operational. For your safety, we strongly
recommend that you contact an authorized
Mercedes-Benz Light Truck Center immedi-
ately to have the system checked; otherwise
the SRS may not be activated when needed
in an accident, which could result in serious
or fatal injury, or it might deploy unexpect-
edly and unnecessarily which could also re-
sult in injury.
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466 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 67).
 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.
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469 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! Stop the vehicle in a
safe location or as soon at is safe to do
so.
Apply the parking brake (page 67).
Contact an authorized Mercedes-Benz
Light Truck Center. Do not add brake
fluid! This will not solve the problem.
Warning!G
Driving with the message Check Brake
Fluid Level
displayed can result in an
accident. Have your brake system checked
immediately. 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.
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470 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 67).
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)
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472 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
B Top Up Coolant
See Operator’s ManualThe coolant level is too low.Add coolant (page 381).
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.
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473 Practical hints
What to do if …
When the message Check engine oil
level at next refueling.
appears while
the engine is running and at operating tem-
perature, the engine oil level has dropped
to approximately the minimum level.
When this occurs, the warning will first
come on intermittently and then stay on if
the oil level drops further.
Visually check for oil leaks. If no obvious oil
leaks are noted, drive to the nearest
service station where the engine oil should
be topped to the required level with an
approved engine oil.For information on approved engine oils,
refer to the Factory Approved Service
Products pamphlet (USA only) or contact
an authorized Mercedes-Benz Light Truck
Center.
Display symbolDisplay messagePossible cause/consequencePossible solution
NCheck engine oil level
at next refueling.The engine oil level is too low.Check the engine oil level (page 380)
and add engine oil as required
(
page 381).
!The engine oil level warning should not be
ignored. Extended driving with the symbol dis-
played could result in serious engine damage
that is not covered by the Mercedes-Benz
Limited Warranty.
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483 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
4Reserve FuelThe fuel level has gone below the reserve
mark.Refuel at the next gas station
(
page 374).
Ultra Low-sulfur
Diesel Fuel OnlyVehicles with diesel engine only:
The fuel level has gone below the reserve
mark.Refuel at the next gas station
(
page 374).
Only use commercially available
vehicular ULTRA-LOW SULFUR
HIGHWAY DIESEL FUEL
(15 ppm SULFUR MAXIMUM).
L Tele Aid
InoperativeOne or more main functions of the
Tele Aid system are malfunctioning.Have the Tele Aid system checked by
an authorized Mercedes-Benz Light
Truck Center.
Tele Aid
BatteryThe emergency power battery for the
Tele Aid system is malfunctioning. If the
vehicle battery is also malfunctioning or
drained, Tele Aid will not be operational.Have the Tele Aid system checked by
an authorized Mercedes-Benz Light
Truck Center.
tFunction
unavailableThis display appears if buttont
ors on the multifunction steering
wheel is pressed and the vehicle is not
equipped with a telephone.
W Top Up
Washer FluidThe fluid level has dropped to about 1/3 of
total reservoir capacity.Add washer fluid (page 383).
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488 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
kLocking System Inoperative
Service RequiredThe differential locks* are
malfunctioning.Do not drive faster than 50 mph
(80 km/h).
Have the vehicle checked at an autho-
rized Mercedes-Benz Light Truck
Center.
Diff. Lock System
Overheated - Wait briefly.The differential locks* are too hot
and have been deactivated as a re-
sult.Continue driving with added caution.
The lock function is unavailable.
Wait for the lock system to cool down.
The differential locks will be reactivat-
ed as soon as they have cooled down.
Stop vehicle,
engage parking brake.A shifting procedure could not be
completed. LOW RANGE* is in neu-
tral position. There is no connection
between the engine and the drive
wheels.Do not attempt to continue driving.
You could otherwise damage the
vehicle’s drivetrain.
Stop the vehicle in a safe location or
soon as it is safe to do so.
Engage the parking brake.
Perform the shifting procedure again
(
page 202).
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