2007 MERCEDES-BENZ GL450 Brake

276 Controls in detail
Driving systems
Switching the Downhill Speed
Regulation on/off
The switch is located on the upper part of
the center console.
Vehicles without enhanced off-road
package*
1DSR on/off
2Indicator lamp
Vehicles with enhanced off-road package*
1DSR on/off
2Indicator lamp
iWhenever DSR is switched on, DSR will use
the programmed default speed to regulate the
vehicle’s speed. The default speed programmed
at the factory is 4 mph (Canada: 6 km / h). The
default speed can be reprogrammed using the
control system (
page 186). The next time DSR
is switched on, DSR will use the newly pro-
grammed default speed to regulate the vehicle’s
speed.
Once DSR is switched on, you can adjust the set
speed using the cruise control lever
(
page 267). Keep in mind that adjusting the
set speed using the cruise control lever with DSR
switched on will not change the programmed
default speed. If DSR is switched off and then
switched on again, DSR will use the programmed
default speed.
Depending on the road surface and level of
downhill grade, the DSR may not be able to
maintain the set speed. To maintain the set
speed, apply the brakes if necessary.

277 Controls in detail
Driving systems
Switching Downhill Speed Regulation on
Press DSR switch1 (page 276).
The indicator lamp2 comes on.
The message
DSR and the set speed ap-
pear in the multifunction display.
For information on how to program the set
speed while driving, see “Adjusting Down-
hill Speed Regulation speed with DSR
switched on” (
page 278).Switching Downhill Speed Regulation off
Press DSR switch1 (page 276).
The indicator lamp2 goes out.
The message
DSR Off appears in the
multifunction display.
Warning!G
If the accelerator pedal is depressed while
the Downhill Speed Regulation is activated,
the vehicle can drive faster than the pro-
grammed set speed. You should therefore
drive downhill with particular caution as it
could otherwise lead to an accident and/or
serious injury to you or others. Keep in mind
that as soon as you remove the foot from
the accelerator pedal with the DSR switched
on, the DSR will start regulating the vehicle’s
speed including use of brakes if required.
Depending on the programmed set speed,
actual vehicle speed and gradient, the DSR
can cause the vehicle to slow down rapidly.
Sudden and unexpected deceleration can
result in loss of vehicle control, causing an
accident and/or serious personal injury to
you and others.
iThe DSR can only be switched on if the vehi-
cle speed is below 18 mph (Canada: 30 km/h).
iIf the DSR is switched on at a speed above
18 mph (Canada: 30 km/h), the message
DSR
Max. speed 18 mph
(Canada: 30 km/h) ap-
pears in the multifunction display.
iAt a speed above approximately 21 mph
(Canada approximately: 35 km/h), the DSR is
automatically switched off. The message
DSR
Off
appears in the multifunction display and an
acoustic signal sounds. For information on how
to switch DSR on again, see “Switching Downhill
Speed Regulation on” (
page 277).

290 Controls in detail
Driving systems
When the highway level is reached, the in-
dicator lamps3 (
page 283) goes out.
The following message appears in the mul-
tifunction display for 5 seconds:
Parktronic system*
The Parktronic system is an electronic
parking aid and designed to assist the
driver during parking maneuvers. It visually
and audibly indicates the relative distance
between the vehicle and an obstacle.
The Parktronic system is automatically
activated when you

switch on the ignition or start the
engine
and

release the parking brake
and

set the automatic transmission to
positionD,R, orN
iThe vehicle is lowered automatically to the
highway level if the vehicle speed is above
60 mph (96 km/h).
Warning!G
Parktronic is a supplemental system. It is
not intended to, nor does it replace, the
need for extreme care. The responsibility
during parking and other critical maneuvers
always remains with the driver.
Special attention must be paid to objects
with smooth surfaces or low silhouettes
(e.g. trailer couplings, painted posts, or road
curbs). Such objects may not be detected by
the system and can damage the vehicle.
The operational function of the Parktronic
system can be affected by dirty sensors,
especially at times of snow and ice. See
“Cleaning the Parktronic system sensors”
(
page 430).
Interference caused by other ultrasonic
signals (e.g. working jackhammers, car
wash, or the air brakes of trucks) can cause
the system to send erratic indications, and
should be taken into consideration.
Warning!G
Make sure no persons or animals are in the
area in which you are maneuvering. You
could otherwise injure them.

291 Controls in detail
Driving systems
The Parktronic system deactivates at
vehicle speeds exceeding approximately
11 mph (18 km/h). At lower vehicle
speeds the Parktronic system turns on
again.
The Parktronic system also deactivates
when you set the automatic transmission
to positionP or depress the parking brake
pedal.
The Parktronic system monitors the sur-
roundings of your vehicle with six sensors
in the front bumper and four sensors in the
rear bumper.
1Sensors in the front bumperRange of the sensors
To function properly, the sensors must be
free of dirt, ice, snow and slush. Clean the
sensors regularly, being careful not to
scratch or damaging the sensors, see
“Cleaning the Parktronic* system sensors”
(
page 430).
!During parking maneuvers, pay special
attention to objects located above or below the
height of the sensors (e.g. planters or trailer
hitches). The Parktronic system will not detect
such objects at close range and damage to your
vehicle or the object may result.
Ultrasonic signals from outside sources (e.g.
working jackhammers, car wash or the air brakes
of trucks) may impair the operation of the
Parktronic system.

293 Controls in detail
Driving systems
As your vehicle approaches an object, one
or more distance segments will illuminate,
depending on the distance. When the
seventh red distance segment illuminates,
you have reached the minimum distance.

Front area: An intermittent acoustic
warning lasting a maximum of
2 seconds will sound as the first red
distance segment illuminates and a
constant acoustic warning lasting a
maximum of 2 seconds will sound for
the second red distance segment. The
signal is canceled when the automatic
transmission is set to positionP, or the
parking brake is set.

Rear area: An intermittent acoustic
warning lasting a maximum of
2 seconds will sound as the first red
distance segment illuminates and a
constant acoustic warning lasting a
maximum of 2 seconds will sound for
the second red distance segment. The
signal is canceled when the automatic
transmission is set to positionD, P, or
the parking brake is set.Switching the Parktronic system*
on/off
You can switch off the Parktronic system
manually.
The Parktronic switch is located on the
upper part of the center console.
Vehicles without enhanced off-road
package*
1Parktronic switch
2Indicator lamp
Vehicles with enhanced off-road package*
1Parktronic switch
2Indicator lamp

294 Controls in detail
Driving systems
Switching off
Press Parktronic switch1.
Indicator lamp2 comes on.
Switching on
Press Parktronic switch1 once more.
Indicator lamp2 goes out.Parktronic system* malfunction
If only the red distance segments illumi-
nate and an acoustic warning sounds,
there is a malfunction in the Parktronic
system. The Parktronic system will auto-
matically switch off after 20 seconds and
the indicator lamp in the Parktronic switch
comes on.
Have the Parktronic system checked
by an authorized Mercedes-Benz Light
Truck Center as soon as possible.
If only the red distance segments illumi-
nate and no acoustic warning sounds, the
Parktronic system sensors are dirty (e.g.
slush, snow or ice) or there is an interfer-
ence from other radio or ultrasonic signals
(e.g. working jackhammers, car wash or
the air brakes of trucks). The Parktronic
system will automatically switch off after
20 seconds and the indicator lamp in the
Parktronic switch comes on.
Switch off the ignition (page 42).
Clean the Parktronic system sensors
(
page 430).
Switch on the ignition (page 42).
or
Check the Parktronic system operation
at another location to rule out interfer-
ence from outside radio or ultrasonic
signals.
iThe Parktronic system switches on
automatically when you switch on the ignition
(
page 42).
Vehicles with original equipment Mercedes-Benz
Trailer Hitch Kit:
The rear Parktronic sensor will automatically
disengage when towing a trailer.

323 Controls in detail
Useful features
Opening the ashtray
Briefly touch cover plate2.
The ashtray opens automatically.
Removing ashtray insert
Grip the ashtray insert1 on the sides
and pull it out upwards.
Reinstalling ashtray insert
Install ashtray insert1.
Close ashtray cover plate2.Rear center console ashtray
(second-row)
1Ashtray
2Ashtray coverOpening rear ashtray
Briefly press ashtray cover2.
The ashtray1 opens automatically.
Removing rear ashtray insert
Grip the insert on the sides and pull it
out upwards.
Reinstalling rear ashtray insert
Install ashtray insert.
Close the ashtray.
Cigarette lighter
Switch on the ignition (page 42).
Push in cigarette lighter.
The cigarette lighter will pop out auto-
matically when hot.
Warning!G
Remove ashtray only with vehicle standing
still. Set the parking brake to secure vehicle
from movement. Set automatic transmis-
sion toP. With the automatic transmission
set toP, turn off the engine.
!Close the ashtray when not in use and be-
fore folding the second-row seats

349 Operation
Driving instructions
Driving instructions
Drive sensibly – save fuel
Fuel consumption, to a great extent,
depends on driving habits and operating
conditions.
To save fuel you should:

Keep tires at the recommended infla-
tion pressures.

Remove unnecessary loads.

Remove carriers* when not in use.

Remove the basic cross bars* when
not in use.

Allow engine to warm up under low
load use.

Avoid frequent acceleration and decel-
eration.

Have all maintenance work performed
at the intervals specified in the
Maintenance Booklet and as required
by the Maintenance System. Contact
an authorized Mercedes-Benz Light
Truck Center.Fuel consumption is also increased by
driving in cold weather, in stop-and-go traf-
fic, on short trips and in hilly areas.
Drinking and driving
Pedals
Warning!G
Drinking and driving and/or taking drugs
and driving are a very dangerous combina-
tion. Even a small amount of alcohol or
drugs can affect your reflexes, perceptions
and judgment.
The possibility of a serious or even fatal
accident are greatly increased when you
drink or take drugs and drive.
Do not drink or take drugs and drive or allow
anyone to drive who has been drinking or
taking drugs.
Warning!G
Make sure that absolutely no objects are ob-
structing the pedal’s range of movement.
Keep the driver’s footwell clear of all obsta-
cles. If there are any floormats or carpets in
the footwell, make sure that the pedals still
have sufficient clearance.
During sudden driving or braking maneu-
vers, the objects could get caught between
the pedals. You could then no longer brake
or accelerate. This could lead to accidents
and injury.