overheating MERCEDES-BENZ GL450 2007 X164 Owner's Manual

110 Safety and Security
Driving safety systems
For more information, see the “Practical
hints” section (
page 436) and
(
page 451).
Off-road - 4-ETS
With the off-road driving program switched
on (
page 279), or with the transmission
in LOW RANGE* mode (
page 203), the
4-ETS designed for off-road use is auto-
matically activated.
!Operational or performance test must only
be conducted on a two-axle dynamometer. If
such tests are necessary, contact an authorized
Mercedes-Benz Light Truck Center. You could
otherwise seriously damage the brake system or
the transfer case which is not covered by the
Mercedes-Benz Limited Warranty.
!Because the ESP® operates automatically,
the engine and ignition must be shut off
(SmartKey in starter switch position0 or1 or
KEYLESS-GO* start/stop button in
position0or1) when testing the parking brake
on a brake test dynamometer and such testing
should be no longer than 10 seconds.
Active braking action through the ESP
® may
otherwise seriously damage the brake system
which is not covered by the Mercedes-Benz
Limited Warranty.
iIf the yellow ESP® warning lampv
comes on while driving, the 4-ETS is being
switched off temporarily to prevent overheating
of the drive wheel brakes. In addition, the
message
ESP inoperative See Operator’s
Manual
appears in the multifunction display.

350 Operation
Driving instructions
Power assistanceBrakes
Warning!G
With the engine not running, there is no
power assistance for the brake and steering
systems. In this case, it is important to keep
in mind that a considerably higher degree of
effort is necessary to brake and steer the ve-
hicle.
Warning!G
After driving in heavy rain for some time
without applying the brakes or through wa-
ter deep enough to wet brake components,
the first braking action may be somewhat re-
duced and increased pedal pressure may be
necessary to obtain expected braking ef-
fect. Maintain a safe distance from vehicles
in front.
Resting your foot on the brake pedal will
cause excessive and premature wear of the
brake pads.
It can also result in the brakes overheating,
thereby significantly reducing their effec-
tiveness. It may not be possible to stop the
vehicle in sufficient time to avoid an acci-
dent.
!Operational or performance test must only
be conducted on a two-axle dynamometer. If
such tests are necessary, contact an authorized
Mercedes-Benz Light Truck Center. You could
otherwise seriously damage the brake system or
the transfer case which is not covered by the
Mercedes-Benz Limited Warranty.
!Because the ESP® operates automatically,
the engine and ignition must be shut off
(SmartKey in starter switch position0 or1 or
KEYLESS-GO* start/stop button in
position0or1) when testing the parking brake
on a brake test dynamometer and such testing
should be no longer than 10 seconds.
Active braking action through the ESP
® may
otherwise seriously damage the brake system
which is not covered by the Mercedes-Benz
Limited Warranty.

351 Operation
Driving instructions
To help prevent brake disk corrosion after
driving on wet road surfaces (particularly
salted roads), it is advisable to brake the
vehicle with considerable force prior to
parking. The heat generated serves to dry
the brakes.
If your brake system is normally only sub-
jected to moderate loads, you should occa-
sionally test the effectiveness of the
brakes by applying above-normal braking
pressure at higher speeds. This will also
enhance the grip of the brake pads.
Refer to the description of the Brake Assist
System (BAS) (
page 105).Brake pad wear or a leak in the system may
be the reason for low brake fluid in the
reservoir.
The brake fluid level in the reservoir may
be too low if the brake warning lamp in the
instrument cluster comes on and an
acoustic warning sounds although the
parking brake is released (
page 437).
Observe additional messages in the multi-
function display that may appear
(
page 472).
Have the brake system inspected
immediately. Contact an authorized
Mercedes-Benz Light Truck Center.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact an authorized
Mercedes-Benz Light Truck Center.
Only install brake pads and brake fluid
recommended by Mercedes-Benz.
After hard braking, it is advisable to drive
on for some time, rather than immediately
park, so that the air stream will cool down
the brakes faster.
Warning!G
Make sure not to endanger any other road
users when carrying out these braking
maneuvers.
Warning!G
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that
safe braking is substantially impaired. This
could result in an accident.
!When driving down long and steep grades,
relieve the load on the brakes by shifting into a
lower gear to use the engine’s braking power.
This helps prevent overheating of the brakes and
reduces brake pad wear.
When using the engine’s braking power, a drive
wheel may not spin for an extended period of
time, e.g. on slippery road surfaces. This may
cause serious damage to the drivetrain which is
not covered by the Mercedes-Benz Limited
Warranty.

370 Operation
Driving instructions

If the transmission repeatedly shifts
between gears on inclines, manually
shift to a lower gear (select 4, 3, 2 or 1)
(
page 200).
A lower gear and reduction of speed re-
duces the chance of engine overload-
ing and/or overheating.

On very steep inclines, not manageable
with automatic transmission in1,
switch on off-road driving program
(
page 280) or LOW RANGE mode*
(
page 203).

When going down a long hill, shift into
a lower gear and use the engine’s brak-
ing effect.
Avoid riding the brakes, thus overheat-
ing the vehicle and trailer brakes.

If the engine coolant rises to an ex-
tremely high temperature (coolant tem-
perature needle approaching the red
zone) when the air conditioning is on,
turn off the air conditioning system.
Engine coolant heat can be additionally
vented by opening the windows,
switching the climate control fan speed
to high and setting the temperature
control to the maximum hot position.

Extreme care must be exercised since
your vehicle with a trailer will require
additional passing distance ahead than
when driving without a trailer.
Because your vehicle and trailer is
longer than your vehicle alone, you will
also need to go much farther ahead of
the passed vehicle before you can re-
turn to your lane.Uncoupling the trailer
!If the trailer should begin to sway, reduce
the vehicle’s speed immediately.
In no case attempt to straighten out the tow
vehicle and trailer by increasing the speed.
Warning!G
While you are coupling or decoupling a trail-
er, make sure that you do not

lock or unlock

open or close
a vehicle door or the tailgate.
The vehicle’s level could change and you
could endanger yourself and/or others as a
result.
Make sure that you do not operate the ADS
button* (
page 281) or the vehicle level
control system (
page 281) when cou-
pling/decoupling the trailer.

454 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
ABSunavailable
See Operator’s ManualIf the yellow ESP® warning
lampv flashes while driving and
this message appears, the electron-
ic traction system has switched off
to prevent overheating of the drive
wheel brakes.As soon as the brakes have cooled off,
the electronic traction system switches
on again.
The message in the multifunction dis-
play disappears and the ESP
® warning
lampv goes out.
The self-diagnosis has not yet been
completed yet.The display will clear after driving a
short distance at a vehicle speed of
above 12 mph (20 km/h).
Cruise control and
SPEEDTRONICinoperativeThe cruise control is malfunctioning.Have cruise control checked by an
authorized Mercedes-Benz Light
Truck Center.
Cruise control--- mphYou have attempted to set a speed
while driving below 20 mph
(30 km/h).Accelerate to a speed exceeding
20 mph (30 km/h) and set the
speed (
page 257).
The ESP® is switched off.Switch on the ESP® (page 105).
The automatic transmission is set to
positionP, R, orN.Set the automatic transmission to
positionD (
page 194).
The vehicle is secured with the
parking brake.Release the parking brake
(
page 60).

460 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
ESPunavailable
See Operator’s ManualThe ESP® was deactivated because
of insufficient power supply. The
charging voltage has fallen below
10 volts.
The brake system is still functioning
normally but without the ABS
available.When the voltage is above this value again, the
ABS is operational again and the message in the
multifunction display should disappear.
If the message in the multifunction display does
not disappear:
Have the generator (alternator) and the
battery checked.
If the yellow ESP® warning
lampv flashes while driving and
this message appears, the electron-
ic traction system has switched off
to prevent overheating of the drive
wheel brakes.As soon as the brakes have cooled off, the
electronic traction system switches on again.
The message in the multifunction display disap-
pears and the ESP
® warning lampv goes
out.
The self-diagnosis has not been
completed yet.The display will clear after driving a short
distance at a vehicle speed of above
12 mph (20 km/h).