Mercedes-Benz 2008 M-Class Operator's Manual page 192

Rocking the vehicle
Rocking the vehicle by shifting between
drive position D and reverse gear R can
help free a vehicle stuck in mud or snow.
The engine control system of this vehicle
electronically limits shifting between
drive position D and reverse gear R to
very low speeds, i.e. approximately
5 mph (9 km/h). To shift between drive
position D and reverse gear R, move the
gear selector lever past the resistance
point up or down.
Working on the vehicle
Warning!
When working on the vehicle, set the
parking brake and shift to park position P.
Otherwise the vehicle could roll away.
Hill start assist system
Warning!
The hill start assist system is not designed
to function as a parking brake and does not
prevent the vehicle from moving when
parked on an incline.
Always set the parking brake in addition to
shifting to park position P.
On uphill grades with a gradient angle of
more than 5°, the hill start assist system
maintains the pressure in the brake sys-
tem for approximately 1 second after you
G
have released the brake pedal. Therefore,
you can start off smoothly without the
vehicle moving immediately after releasing
the brake pedal.
Controls in detail
Automatic transmission
The hill start assist system is inactive
when starting off on a level road or
G
downhill grades
with the transmission in neutral
position N
with the parking brake set
®
if the ESP has switched off due to a
malfunction
Towing a trailer
If you tow a trailer, note the following
points:
Manually shift to a lower gear range
( page 192) if the transmission hunts
between gears on inclines.
A lower gear range and reduction of
speed reduces the chance to overload
or overheat the engine.
For more information on trailer towing, see
the "Operation" section ( page 328).
191