Tire pressure MERCEDES-BENZ R350 2008 W251 Service Manual

442 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
Check tires,
then restart
Run Flat Indicator.
There was a warning message about
a loss in the tire inflation pressure
and the Run Flat Indicator has not
been reactivated yet.Make sure that the correct tire inflation pressure is set
for each tire.
Then restart the Run Flat Indicator (page 375).
Run Flat Indicator
InoperativeRun Flat Indicator is malfunctioning.Have the Run Flat Indicator checked by an authorized
Mercedes-Benz Light Truck Center.
Tire Pressure
Check TiresThe Run Flat Indicator indicates that
the pressure is too low in one or more
tires.Carefully bring the vehicle to a halt, avoiding abrupt
steering and braking maneuvers. Observe the traffic
situation around you.
Check and adjust tire inflation pressure as required
(
page 373).
If necessary, replace the wheel (page 492).
Restart the Run Flat Indicator after adjusting the tire
inflation pressure values (
page 375).
Tire pressure
displayed after
driving for
a few minutes
.
Vehicles with Advanced TPMS*:
The tire inflation pressure is being
checked.Drive the vehicle for a few minutes.

443 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.
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 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.

462 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
HTire Pressure(s)
Please CorrectVehicles with Advanced TPMS*:
The tire pressure is too low in one
or more tires.Check and correct tire inflation pressure as
required (
page 373).
Tire Pressure
Caution - Tire DefectOne or more tires are deflating.Carefully bring the vehicle to a halt, avoiding
abrupt steering and braking maneuvers.
If necessary, change the wheel (page 492).
Caution: Tire DefectOne or more tires are deflating.
Vehicles with Advanced TPMS*:
The respective tire is indicated in
the multifunction display.Carefully bring the vehicle to a halt, avoiding
abrupt steering and braking maneuvers.
If necessary, change the wheel (page 492).
Warning!G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle. You
may lose control of the vehicle. Continued
driving with a flat tire will cause excessive
heat build-up and possibly a fire.

463 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
HTire Pressure
Check TiresThe tire pressure in one or more tires is
already below the minimum value.Carefully bring the vehicle to a halt, avoid-
ing abrupt steering and braking maneuvers.
Check and adjust tire pressure as required
(
page 373).
If necessary, change the wheel
(
page 492).
Check TiresThe tire pressure in one or more tires is
already below the minimum value.
Vehicles with Advanced TPMS*:
The respective tire is indicated in the
multifunction display.Carefully bring the vehicle to a halt, avoid-
ing abrupt steering and braking maneuvers.
Check and adjust tire pressure as required
(
page 373).
If necessary, change the wheel
(
page 492).
Warning!G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle. You
may lose control of the vehicle. Continued
driving with a flat tire will cause excessive
heat build-up and possibly a fire.

471 Practical hints
Where will I find ...?
Setting up the collapsible wheel chock
The collapsible wheel chock serves to ad-
ditionally secure the vehicle, e.g. while
changing the wheel.
1Tilt the plate upward
2Fold the lower plate outward
3Insert the plateTilt both plates upward1.
Fold the lower plate outward2.
Guide the tabs of the lower plate all the
way into the openings of base plate3.
For information on where to place wheel
chocks when changing a wheel, see
“Lifting the vehicle” (
page 493).
Spare wheel
Warning!G
The dimensions of the spare wheel are
different from those of the road wheels. As
a result, the vehicle handling characteristics
change when driving with a spare wheel
mounted. Adapt your driving style accord-
ingly.
The spare wheel is for temporary use only.
When driving with a spare wheel mounted,
ensure proper tire inflation 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
spare wheel replaced with a regular road
wheel.
Never operate the vehicle with more than
one spare wheel mounted.
Do not switch off the ESP
® with a spare
wheel mounted.

492 Practical hints
Flat tire
Preparing the vehicle
Vehicles with AIRMATIC*:
Make sure the vehicle level is set to
highway level (
page 276).
Park the vehicle in a safe distance from
moving traffic on a hard, flat surface
when possible.
Turn on the hazard warning flasher
(
page 150).
Turn the steering wheel so that the
front wheels are in a straight-ahead
position.
Set the parking brake (page 65).
Set the automatic transmission to
position P (
page 190).
Turn off the engine (page 66).
Have any passenger exit the vehicle at
a safe distance from the roadway.
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*:
Turn off the engine by pressing the
KEYLESS-GO* button once
(
page 66).
Open the driver’s door (this puts
the starter switch in position 0,
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.
Warning!G
The dimensions of the spare wheel are
different from those of the road wheels. As
a result, the vehicle handling characteristics
change when driving with a spare wheel
mounted. Adapt your driving style accord-
ingly.
The spare wheel is for temporary use only.
When driving with spare wheel mounted,
ensure proper tire inflation 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
spare wheel replaced with a regular road
wheel.
Never operate the vehicle with more than
one spare wheel mounted.
Do not switch off the ESP
® with a spare
wheel mounted.
iOpen doors only when conditions are safe to
do so.

499 Practical hints
Flat tire
Inflating the collapsible tire
Take the electric air pump out of the
vehicle tool kit storage well
(
page 467).
Electric air pump
1Flap
2On/off switch
3Electrical plug
4Air hose with pressure gauge and vent
screw
5Union nut
Open flap 1 on electric air pump.
Pull out electrical plug 3 and air hose
with pressure gauge 4.
Remove the valve cap from the
collapsible tire valve.
Screw union nut 5 onto the
collapsible tire valve.
Insert electrical plug 3 into a power
outlet (
page 314).
Turn the SmartKey in the starter switch
to position1.
Vehicles with KEYLESS-GO*:
Press the KEYLESS-GO start/stop
button once without depressing the
brake pedal.
Press I on electric air pump switch 2.
The electric air pump should now
switch on and inflate the collapsible
tire.
Warning!G
Inflate collapsible tire only after the wheel is
properly mounted.
Inflate the collapsible tire using the electric
air pump (
page 467) before lowering the
vehicle.
Warning!G
Observe instructions on air pump label.
!Do not lower the vehicle before inflating the
collapsible tire. Otherwise the rim may be dam-
aged.
!The cigarette lighter (page 312) is not de-
signed for use with the electric air pump. Use a
power outlet (
page 314) for electric air pump
operation.


500 Practical hints
Flat tire
Inflate the spare wheel tire to the
recommended tire inflation pressure
given in the “Technical data” section
(
page 529).
This takes about 5 minutes for the
collapsible tire.
Press 0 on electric air pump switch 2.
Turn the SmartKey in the starter switch
to position0.
Vehicles with KEYLESS-GO*:
Press the KEYLESS-GO start/stop
button twice without depressing
the brake pedal.
If the tire inflation pressure is above
the recommended tire inflation pres-
sure given in this Operator’s Manual,
release excess tire inflation pressure
using the vent screw.
Detach the electric air pump.
Store the electrical plug and the air
hose behind the flap and place the
electric air pump back in the vehicle
tool kit storage well.
Warning!G
Air hose 4 and union nut5 can become
hot during inflation. Exercise proper caution
to avoid burning yourself when using the
equipment.
!Do not operate the electric air pump longer
than 8 minutes without interruption. Otherwise it
may overheat.
You may operate the electric air pump again
after it has cooled off.
!Please compare the recommended tire in-
flation pressure for your vehicle with the tire in-
flation pressure on the yellow label located on
the spare wheel rim.
If the tire inflation pressure on the yellow label
on the spare wheel rim differs from the values
given in this Operator’s Manual, inflate the tire to
the recommended tire inflation pressure given
on the yellow label on the spare wheel rim.Warning!G
Follow recommend tire inflation pressures.
Do not overinflate tires. Overinflating tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes,
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.


501 Practical hints
Flat tire
Lowering the vehicle
Vehicles with scissors-type jack:
Attach ratchet to vehicle jack in such a
way that the wordDOWN can be seen.
Lower the vehicle until it is resting fully
on its own weight:
Vehicles with screw-type jack:
Turn crank counterclockwise.
Vehicles with scissors-type jack:
Turn ratchet in directionDOWN.
Remove the jack.1-5Wheel bolts
6Wheel wrench
Tighten the five wheel bolts evenly,
following the diagonal sequence
illustrated (1to5), until all bolts
are tight. Observe a tightening torque
of 110 lb-ft (150 Nm).
Store jack and all other vehicle tool kit
items back into the storage well.
Warning!G
Inflate collapsible tire only after the wheel is
properly mounted.
Inflate the collapsible tire using the electric
air pump (
page 499) before lowering the
vehicle.
Warning!G
Have the tightening torque checked after
changing a wheel. The wheels could come
loose if they are not tightened to a torque of
110 lb-ft (150 Nm).
iThe removed road wheel cannot be stored in
the spare wheel well under the cargo compart-
ment floor, but should be transported in the
cargo compartment wrapped in a protective
wrap.
Vehicles with TPMS or Advanced TPMS*:
Do not activate the tire inflation pressure moni-
tor until a full size wheel/tire with functioning
sensor has been placed back into service on the
vehicle.

529 Technical data
Rims and tires
Rims and tires
!Only use tires which have been tested and
approved by Mercedes-Benz. Tires approved by
Mercedes-Benz are developed to provide best
possible performance in conjunction with the
driving safety systems on your vehicle such as
ABS or ESP
®. Tires specially developed for your
vehicle and tested and approved by
Mercedes-Benz can be identified by finding the
following on the tire’s sidewall:

MO = Mercedes-Benz Original equipment
tires
Using tires other than those approved by
Mercedes-Benz may result in damage that is
not covered by the Mercedes-Benz Limited
Warranty.
!Using tires other than those approved by
Mercedes-Benz can have detrimental effects,
such as

poor handling characteristics

increased noise

increased fuel consumption
Moreover, tires and rims not approved by
Mercedes-Benz may, under load, exhibit dimen-
sional variations and different tire deformation
characteristics that could cause them to come
into contact with the vehicle body or axle parts.
Damage to the tires or the vehicle may be the
result.
iFurther information on tires and rims is
available at any authorized Mercedes-Benz Light
Truck Center. A placard with the recommended
tire inflation pressures is located on the driver’s
door B-pillar (
page 366). Some vehicles may
have supplemental tire inflation pressure infor-
mation for driving at high speeds (
page 372)
or for vehicle loads less than the maximum
loaded vehicle condition (
page 372). If such
information is provided, it can be found on the
placard located on the inside of the fuel filler
flap.The tire inflation pressure should be checked
regularly and should only be adjusted on cold
tires. Follow tire manufacturer’s maintenance
recommendation included with vehicle.
iThe following pages also list the approved
wheel rim and tire sizes for equipping your vehi-
cles with winter tires. Winter tires are not avail-
able as standard or optional factory equipment,
but can be purchased from an authorized
Mercedes-Benz Light Truck Center.
Depending on vehicle model and the standard or
optional factory-equipped wheel rim/tire
configuration on your vehicle (Appearance
Package, Sport Package etc.), equipping your
vehicle with winter tires approved for your
vehicle model may also require the purchase of
two or four wheel rims of the recommended size
for use with these winter tires. Contact an
authorized Mercedes-Benz Light Truck Center
for more information.