2007 MERCEDES-BENZ GL320CDI engine

476 Practical hints
What to do if …
When the message Add 1 qt. engine oil
at next refueling
(Canada: 1 liter)
appears while the engine is running and at
operating temperature, the engine oil level
has dropped to approximately the mini-
mum 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 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 messagesPossible cause/consequencePossible solution
NCheck eng. oil level
at next refuelingThe engine oil level is too low.Check the engine oil level (page 381).
USA only:
Add 1 qt. engine oil
at next refueling
Canada only:
Add 1 liter engine oil
at next refueling
The engine oil level is too low.Add engine oil (page 382) and check
the engine oil level (
page 381).
Engine oil level
cannot be measuredThe measuring system is
malfunctioning.Have the measuring system checked by
an authorized Mercedes-Benz Light Truck
Center.

477 Practical hints
What to do if …
Display symbolDisplay messagesPossible cause/conse-
quencePossible solution
NEngine oil level
Stop car, turn engine offThere is no oil in the engine.
There is a danger of engine
damage.Carefully bring the vehicle to a halt as soon as it
is safe to do so in a safe location.
Turn off the engine.
Add engine oil (page 382) and check the en-
gine oil level (
page 381).
Engine oil level
Reduce oil levelYou have added too much
engine oil. There is a risk of
damaging the engine and/or
the catalytic converter (gaso-
line engine) or the oxidation
catalyst (diesel engine).Have oil siphoned or drained off.
Observe all legal requirements with respect to
its disposal.
Engine oil level
Visit workshopThe engine oil has dropped to
a critical level.Check the engine oil level (page 381) and add
oil as required (
page 382).
If you must add engine oil frequently, have the
engine checked for possible leaks.
!The engine oil level warnings should not be
ignored. Extended driving with the symbol dis-
played could result in serious engine damagethat is not covered by the Mercedes-Benz
Limited Warranty.

479 Practical hints
What to do if …
Display symbolDisplay messagesPossible cause/consequencePossible solution
FKey
not detectedThe SmartKey with
KEYLESS-GO* is not recognized
while the engine is running
because

the SmartKey with
KEYLESS-GO* is not in the
vehicle

there is strong
radio-frequency interference
Stop the vehicle in a safe location or as
soon as it is safe to do so.
Apply the parking brake (page 68).
Search for the SmartKey with
KEYLESS-GO*.
Otherwise the vehicle cannot be centrally
locked nor can the engine be started
again after the engine is stopped.
The SmartKey with
KEYLESS-GO* is momentarily
not recognized.Change the position of the SmartKey with
KEYLESS-GO* in the vehicle.
Operate the vehicle with the SmartKey in
the starter switch if necessary.
Key
not detectedThe SmartKey with
KEYLESS-GO* is not recognized
while the ignition is switched on
(
page 41) and a door is
opened or closed and the
SmartKey with KEYLESS-GO* is
not in the vehicle.
Search for the SmartKey with
KEYLESS-GO*.
Otherwise the vehicle cannot be locked
nor can the engine be started.
Change the position of the SmartKey with
KEYLESS-GO* in the vehicle.

480 Practical hints
What to do if …
Display symbolDisplay messagesPossible cause/consequencePossible solution
FKey detected
in vehicleA SmartKey with KEYLESS-GO*
left in the vehicle was detected
while trying to lock the vehicle
from the outside.Take the SmartKey with KEYLESS-GO*
out of the vehicle.
Remove keyYou have forgotten to remove
the SmartKey.Remove the SmartKey from the starter
switch.
You need a new keyThere is no additional code avail-
able for SmartKey or SmartKey
with KEYLESS-GO*.Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Change
key batteriesThe batteries in the SmartKey
with KEYLESS-GO* are dis-
charged.Replace the batteries (page 506).
Don’t forget
your keyThis message appears for a
maximum of 60 seconds if the
driver’s door is opened with the
engine shut off and no SmartKey
in the starter switch.
This message is only a reminder.Insert the SmartKey in the starter switch
(
page 42).
or
Take the SmartKey with KEYLESS-GO*
with you when leaving the vehicle.

493 Practical hints
What to do if …
Display symbolDisplay messagesPossible cause/consequencePossible solution
kDiff. lock system malfunct.
Visit workshopThe 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 off.
mStop vehicle
Engage parking brakeA 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.
Let the vehicle coast to a halt.
 Engage the parking brake.
Perform the shifting procedure again
(
page 204).

494 Practical hints
What to do if …
Display symbolDisplay messagesPossible cause/consequencePossible solution
mStop vehicle
Engage parking brakeThe LOW RANGE system* could only
partially carry out the shifting proce-
dure or it could not carry out the
shifting procedure at all. The system
is in idle mode. No power is being
transmitted to the drive wheels.Do not continue driving.
Carefully let the vehicle coast to a
stop.
Firmly depress the parking brake.
Shift gears again in HIGH RANGE or
LOW RANGE (
page 204).
Visit workshop
If parked engage pk. brakeThe LOW RANGE system* is
malfunctioning.Do not drive faster than 50 mph
(80 km/h).
Engage the parking brake if parked.
Visit an authorized Mercedes-Benz
Light Truck Center as soon as possi-
ble.
max. speed 25 mphSpeed too high for shifting proce-
dure.Continue driving more slowly.
max. speed 40 mphSpeed too high for shifting proce-
dure.Continue driving more slowly.
shift briefly
into NYou have reduced engine speed. You
may now carry out a shifting proce-
dure.Briefly shift automatic transmission
to positionN.
Shifting procress canceled
ReactivateThe shifting procedure was not car-
ried out.Repeat the shifting procedure if
desired.

503 Practical hints
Opening/closing in an emergency
Opening/closing in an emergency
Power tilt/sliding sunroof*
You can open or close the tilt/sliding
sunroof manually should an electrical
malfunction occur.
The tilt/sliding sunroof drive is located
behind a cover on the overhead control
panel.
1Cover
Remove the SmartKey from the starter
switch.Vehicles with KEYLESS-GO*:
Turn off the engine by pressing the
KEYLESS-GO* start/stop button
(
page 70).
Open the driver’s door (this puts
the starter switch in position 0, same
as with the SmartKey removed from
the starter switch). The driver’s door
can then be closed again.
Press on cover1 at the position indi-
cated by the arrow.
Take off cover1.
2Crank
Take crank2 out of the Operator’s
Manual pouch.
Insert crank2 into hole.
Turn crank2 clockwise to

slide sunroof closed

raise sunroof at the rear
Turn crank2 counterclockwise to

slide sunroof open

lower sunroof at the rear
iThe hole may be covered by a noise
reduction padding. You will then have to push the
crank through the padding at the perforated
mark.
iTurn crank2 slowly and smoothly.
The tilt/sliding sunroof must be synchronized if
it has been operated manually (
page 255).

523 Practical hints
Flat tire
Flat tire
Preparing the vehicle
Park the vehicle in a safe distance from
moving traffic on a hard, flat surface
when possible.
Turn on the hazard warning flasher
(
page 151).
Turn the steering wheel so that the
front wheels are in a straight-ahead
position.
Set the parking brake (page 60).
Set the automatic transmission to park
positionP (
page 194).
Turn off the engine (page 41).
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*:
Turn off the engine by pressing the
KEYLESS-GO* button once
(
page 70).
Open the driver’s door (this puts
the starter switch in position0,
same as with the SmartKey re-
moved from the starter switch). The
driver’s door then can be closed
again.
Remove the KEYLESS-GO*
start/stop button from the starter
switch (
page 43).
Have any passenger exit the vehicle at
a safe distance from the roadway.
Warning!G
The dimensions of the Minispare wheel are
different from those of the road wheels. As
a result, the vehicle handling characteristics
change when driving with a Minispare wheel
mounted. Adapt your driving style accord-
ingly.
The Minispare wheel is for temporary use
only. When driving with a Minispare wheel
mounted, ensure proper tire pressure and
do not exceed a vehicle speed of
50 mph (80 km/h).
Drive to the nearest Mercedes-Benz Light
Truck Center as soon as possible to have the
Minispare wheel replaced with a regular
road wheel.
Never operate the vehicle with more than
one spare wheel mounted.
Do not switch off the ESP
® when a
Minispare wheel is mounted.
Warning!G
Your vehicle is equipped with air suspen-
sion. Do not open or close any doors or the
tailgate while mounting a spare wheel. The
vehicle could rise or lower to a previously se-
lected level. You or others could be injured
as a result.
iOpen door only when conditions are safe to
do so.