Mercedes-Benz GL-Class 2012 Owners Manual - Manual (Page 211)

lost and steering would no longer be possible.
The differential locks must therefore only be
activated off-road and only if activating the
other driving systems (4ETS, ESP
® and LOW
Range off-road gear) is no longer sufficient.
Engaging the differential locks
!
Pull away slowly when the differential
locks are activated.
Function or performance tests may only be
performed on a 2-axle dynamometer. If you
wish to operate the vehicle on such a
dynamometer, please consult an
authorized Mercedes-Benz Center
beforehand. You could otherwise damage
the drive train or the brake system.
Automatic mode
Use automatic mode ; for all driving
situations, including driving off-road or when
fording.
In automatic mode, the differential locks are
engaged and disengaged according to driving
requirements. This guarantees sufficient
traction for most driving situations with
unrestricted vehicle steerability.
X Start the engine.
The differential locks are in automatic
mode. The indicator lamp in selector
wheel : lights up above symbol for
automatic mode ;.
Engaging manually
G WARNING
Never drive on a paved surface with the center
and rear axle differential locks manually
engaged. Ability to steer the vehicle is greatly
reduced when the differential locks are
manually engaged, increasing the risk of an
accident.
For safety reasons, the locks are
automatically released at a vehicle speed
above 31 mph (50 km/h). Nevertheless, you
should only manually lock the differential if
absolutely necessary because engaged locks
will restrict the vehicle drivetrain while
cornering and cause the vehicle to chatter.
This could cause you to lose control of the
vehicle and cause an accident.
! The differential locks must not be
activated when the vehicle is being towed
or while the wheels are spinning.
Only engage the differential locks manually if
traction in automatic mode is insufficient.
The differential locks can be activated
manually up to a speed of 19 mph
(30 km/h).
X Start the engine.
X Turn selector wheel : to desired position
= or ?.
The indicator lamp in selector wheel :
lights up at the corresponding symbol.
The engaged differential appears in the
multifunction display:
A
The differential lock for the transfer case
is locked.
If you have not previously selected the off-
road menu (
Y page 222) in the on-board
Off-road driving systems
209
Driving and parking
Z