Mercedes-Benz GLK 300 4MATIC 2012 Owner's Manual page 216

Towing a trailer
If you attach a trailer, make sure that you have
correctly established the electrical connec-
tion. This can be accomplished by checking
the trailer lighting.
Off-road driving systems
4MATIC (permanent all-wheel drive)
G
WARNING
4MATIC cannot reduce the risk of an accident
if you drive too fast.
If a drive wheel spins due to insufficient grip:
only depress the accelerator pedal as far as
R
necessary when pulling away.
accelerate less when driving.
R
adapt your driving style to suit road and
R
traffic conditions.
! Never tow the vehicle with one axle
raised. This may damage the transfer case.
Damage of this sort is not covered by the
Mercedes-Benz implied warranty. All
wheels must remain either on the ground
or be fully raised. Observe the instructions
for towing the vehicle with all wheels in full
contact with the ground.
4MATIC ensures that all four wheels are per-
manently driven. Together with ESP
ETS, it improves the traction of your vehicle
whenever a drive wheel spins due to insuffi-
cient grip.
i
In wintry driving conditions, the maximum
effect of 4MATIC can only be achieved if
you use winter tyres (M+S tyres), with snow
chains if necessary.
! When testing the parking brake, operate
the vehicle only briefly (for a maximum of
ten seconds) on a brake test dynamometer.
When doing this, turn the key to position
0 or 1 in the ignition. Failure to do this can
cause damage to the drive train or the
brake system.
! A function or performance test should
only be carried out on a twin-axle dyna-
mometer. Before you operate the vehicle
on such a dynamometer, please consult a
qualified workshop. You could otherwise
damage the drive train or the brake system.
For information about "Driving off-road", see
( page 170).
Y
DSR (Downhill Speed Regulation)
Important safety notes
i
DSR (Downhill Speed Regulation) is only
available for vehicles with the Off-Road
Engineering package.
DSR is an aid to assist you when driving down-
hill. It keeps the speed of travel at the speed
selected on the on-board computer. The
steeper the downhill gradient, the greater the
DSR braking effect on the vehicle. When driv-
ing on flat stretches of road or on an uphill
gradient, the DSR braking effect is minimal or
non-existent.
G
WARNING
DSR is only an aid designed to assist you when
driving downhill. You are responsible for keep-
ing control of the vehicle and for assessing
whether the downhill gradient can be man-
®
and
aged.
When activating DSR the vehicle may brake
suddenly due to DSR intervening. This is
dependent on the downhill gradient and the
difference between the current speed and the
speed set. DSR may not always be able to
keep to the set speed, depending on road sur-
face and tyre conditions. You could lose con-
trol of the vehicle and cause an accident.
Select a set speed suitable for the prevailing
conditions and when necessary, apply the
brakes manually.
DSR controls the vehicle's speed when it is
activated and the transmission is in position
D, R or N. By accelerating or braking, you can
Off-road driving systems
213
Z