Page 249 of 360
249 Practical hints
What to do if …
Display
Possible cause
Suggested solution
Category
#
BATTERY/ALTERNATOR
VISIT WORKSHOP!
The battery was charged with a bat-
tery charger or jump started.
Have the battery checked at a
service station.
2
The battery is no longer charging.
Possible causes:
alternator malfunctioning
broken poly-V-belt
Stop immediately and check
the poly-V-belt.
If it is broken:
Do not continue to drive. Oth-
erwise the engine will overheat
due to an inoperative water
pump which may result in seri-
ous engine damage not cov-
ered by the Mercedes-Benz
Limited Warranty. Notify an
authorized Mercedes-Benz
Light Truck Center.
If it is intact:
Turn off unnecessary electric
consumers.
Drive immediately to the near-
est authorized Mercedes-Benz
Light Truck Center.
Page 296 of 360

296 Practical hintsBatteryDisconnecting the battery
Turn off all electrical consumers.
Disconnect the battery negative lead.
Remove the cover from the positive ter-
minal.
Disconnect the battery positive lead.
Remove the breather hose from the
battery.
Reconnecting the battery
Turn off all electrical consumers.
Connect the positive lead and fasten its
cover.
Connect the negative lead.
Install the breather hose.
!Never loosen or detach battery termi-
nal clamps while the engine is running
or the key is in the starter switch. Oth-
erwise the alternator and other elec-
tronic components could be severely
damaged.
iWith a disconnected battery
you will no longer be able to turn
the key in the starter switch
the selector lever will remain
locked in positionP
!Never invert the terminal connections.!The battery, its filler caps and the vent
tube must always be securely installed
when the vehicle is in operation.
iThe following procedures must be car-
ried out following any interruption of
battery power (e.g. due to reconnec-
tion):
Set the clock (see COMAND opera-
tor’s manual).
Resynchronize the front seat head
restraints and seat adjustment fore,
aft (
page 93).
Resynchronize the ESP
(page 257).
Page 311 of 360
311 Technical data
Layout of poly-V-belt drive
Layout of poly-V-belt drive
For dimensions of the poly-V-belt, see
technical data (
page 312).
G500/G55AMG
1Automatic belt tensioner
2Power steering pump
3Air conditioner compressor
4Crankshaft
5Coolant pump
6Generator (alternator)
7Idler pulley
Page 314 of 360
314 Technical dataElectrical system
Electrical system
G500
G55AMG
Generator (alternator)
14 V/150 A
14 V/150 A
Starter motor
12 V/1.7 kW
12 V/1.7 kW
Battery
12 V/90 Ah
12 V/90 Ah
Spark plugs
Bosch F 8 DPER
Beru 14 FGH 8 DPUR X 2
NGK PFR5R-11
Electrode gap
0.039 in (1.0 mm)
0.039 in (1.0 mm)
Tightening torque
15 – 22 ft.lb (20 – 30 Nm)
15 – 22 ft.lb (20 – 30 Nm)
Page 327 of 360

327 Technical terms
Lock button
Button on the door which indicates
whether the door is locked or un-
locked. Pushing the lock button down
on an individual door from inside will
lock that door.
Memory function*
Used to store three individual seat,
steering wheel and mirror positions for
each key.
Menu
The control system displays are ar-
ranged in menus. Each menu contains
a number of commands for particular
systems. In the Audio menu, for exam-
ple, you will find the commands
Select
radio station
or Operate CD player
.
Using commands you can directly
change the settings for your vehicle.MON
(M
otor O
ctane N
umber)
The Motor Octane Number for gasoline
as determined by a standardized meth-
od. It is an indication of a gasoline's
ability to resist undesired detonation
(knocking). The average of both the
MON (Motor Octane Number) and
->RON (Research Octane Number) is
posted at the pump, also known as AN-
TI-KNOCK INDEX.
Multifunction display
A display field in the instrument cluster
used to present information provided
by the control system.
Overspeed range
Engine speeds within the red marking
of the tachometer dial. Avoid this en-
gine speed range, as it may result in se-
rious engine damage that is not
covered by the Mercedes-Benz Limited
Warranty.Poly-V-belt drive
Drives engine-components (alternator,
AC compressor, etc.) from the engine.
Power train
Collective term designating all compo-
nents used to generate and transmit
motive power to the drive axles, includ-
ing
engine
clutch/torque converter
transmission
transfer case
drive shaft
differential
axle shafts/axles
Rear Park Assist*
System which uses visual and acoustic
signals to assist the driver during park-
ing maneuvers.