Mercedes-Benz 2009 M-Class Operator's Manual page 388

Practical hints
Jump starting
! Jump starting should only be performed
using the jump-start terminals located in
the engine compartment.
Avoid repeated and lengthy starting
attempts.
Do not attempt to start the engine using a
battery quick-charge unit.
If the engine does not run after several
unsuccessful starting attempts, have it
checked at the nearest authorized
Mercedes-Benz Center.
Excessive unburned fuel generated by
repeated failed starting attempts may
damage the catalytic converter
present a fire risk.
Make sure the jumper cables do not have
loose or missing insulation.
Make sure the cable clamps do not touch
any other metal part while the other end is
still attached to a battery.
28 Vehicles with gasoline engine only.
29 Vehicles with gasoline engine only.
386
If the battery is discharged, the engine can be
started with jumper cables and the battery of
another vehicle. Observe the following:
Jump starting should only be performed
R
when the engine and catalytic converter
are cold.
Do not start the engine if the battery is
R
frozen. Let the battery thaw out first.
Only jump start from batteries with the
R
same voltage rating (12 V). Jump starting
with a more powerful battery could damage
the vehicle's electrical system, which will
not be covered by the Mercedes-Benz
28
and may
Limited Warranty.
Only use jumper cables with sufficient
R
cross-section and insulated terminal
clamps.
Always make sure the jumper cables are
R
not on or near pulleys, fans or other parts
that move when an engine is started or
running.
The jump-start contacts are located in the
engine compartment on the passenger side.
29
Negative terminal
1
Positive terminal
2
Positive terminal cover
3
X
Make sure the two vehicles do not touch.
X
Switch off all electrical consumers.
X
Engage the parking brake.
X
Make sure the automatic transmission is in
park position P.
X
Open the hood.
X
Flip up cover of positive terminal
3
direction of arrow.
X
Remove cover from negative terminal 1.
in
2