Page 274 of 400

274 Practical hintsWhat to do if …
What to do if …Lamps in instrument clusterGeneral information:
If a bulb in the instrument cluster fails to 
come on during the bulb self-check when turning the SmartKey in the starter switch 
to position2, have it checked and replaced 
if necessary.Problem
Possible cause
Suggested solution
-
The yellow ABS malfunction 
indicator lamp comes on while 
driving.
The ABS has detected a malfunction and has 
switched off. The BAS and the ESP are also 
switched off (see messages in display).
The brake system is still functioning normally 
but without the ABS available.
Continue driving with added caution. 
Wheels may lock during hard braking, 
reducing steering capability. 
Have the system checked at an autho-
rized Mercedes-Benz Center as soon 
as possible.
Failure to follow these instructions 
increases the risk of an accident.
Read and observe messages in the 
display (
page 280).
The charging voltage has fallen below ten 
volts. The ABS has switched off.
When the voltage is above this value 
again, the ABS is operational again.
If necessary, have the generator 
(alternator) and battery checked. 
     
        
        Page 285 of 400
285 Practical hints
What to do if …
Display symbol
Display message
Possible cause
Possible solution
#
BATTERY/ALTERNATOR
VISIT WORKSHOP!
The battery was charged with a battery 
charger or jump started.
Have the battery checked at a service 
station. 
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. Otherwise 
the engine will overheat due to an 
inoperative water pump which may 
result in damage to the engine. Notify 
an authorized Mercedes-Benz Center.
If it is intact:
Drive immediately to the nearest 
authorized Mercedes-Benz Center.
UNDERVOLTAGE
ENGINE ON!
The battery has insufficient voltage and 
can no longer supply the convenience 
functions such as seat heater*.
Start the engine (
page 43).
UNDERVOLTAGE
SWITCH CONSUMERS OFF!
The battery is malfunctioning.
Have the battery checked at a service 
station. 
     
        
        Page 323 of 400

323 Practical hints
Battery
Battery
The battery is located in the engine 
compartment on the right hand side.
Removal of filter box:
Release the three clamps1.
Remove filter box.
Installation of filter box:
Insert filter box properly.
Secure it with the three clamps1.
Warning!
G
Failure to follow these instructions can 
result in severe injury or death.
Never lean over batteries while connecting, 
you might get injured.
Battery fluid contains sulfuric acid. Do not 
allow this fluid to come in contact with eyes, 
skin or clothing. In case it does, immediately 
flush affected area with water and seek 
medical help if necessary.
A battery will also produce hydrogen gas, 
which is flammable and explosive. Keep 
flames or sparks away from battery, avoid 
improper connection of jumper cables, 
smoking, etc.
!Never loosen or detach battery termi-
nal clamps while the engine is running 
or the SmartKey is in the starter switch. 
Otherwise the alternator and other 
electronic components could be se-
verely damaged.
Have the battery checked regularly by 
an authorized Mercedes-Benz Center. 
Refer to Service Booklet for mainte-
nance intervals or contact your autho-
rized Mercedes-Benz Center for further 
information.Warning!
G
Do not place metal objects on the battery as 
this could result in a short circuit. 
Use leak-proof battery only to avoid the risk 
of acid burns in the event of an accident. 
     
        
        Page 339 of 400
339 Technical data
Layout of poly-V-belt drive
Layout of poly-V-belt drive
C230KompressorSport
1Power steering pump
2Idler pulley
3Supercharger
4Automatic belt tensioner
5Air conditioning compressor
6Crankshaft
7Coolant pump 
8Generator (alternator)
C 240/C 320 (all models)
1Automatic belt tensioner
2Power steering pump 
3Air conditioning compressor
4Crankshaft 
5Coolant pump
6Generator (alternator)
7Idler pulley
C32AMG
1Idler pulley 
2Idler pulley 
3Supercharger
4Automatic belt tensioner
5Power steering pump 
6Air conditioning compressor
7Crankshaft 
8Coolant pump
9Generator (alternator) 
     
        
        Page 346 of 400
346 Technical dataElectrical system
Electrical systemModel
C230KompressorSport
C 240/C 320 (all models)
C32AMG
Generator (alternator)
14 V/120 A
14 V/120 A
14 V/120 A
Starter motor
12 V/1.1 kW
12 V/1.7 kW
12 V/1.7 kW
Battery
12 V/100 Ah
12 V/100 Ah
12 V/100 Ah
Spark plugs
Bosch F 6 MPP 332
Bosch F 8 DPP 332
NGK PFR 5 R-11
NGK IFR 6 D 10
Electrode gap
0.031 in (0.8 mm)
0.039 in (1.0 mm)
0.039 in (1.0 mm)
Tightening torque
18–22lb-ft (25–30Nm)
15–22lb-ft (20–30Nm)
15 – 22 lb-ft (20 – 30 Nm) 
     
        
        Page 363 of 400

363 Technical terms
Instrument cluster
The displays and indicator/warning 
lamps in the driver’s field of vision, 
including the tachometer, speedo-
meter, engine temperature display and 
fuel gauge.
Kickdown
Depressing the accelerator past the 
point of resistance shifts the transmis-
sion down to the lowest possible gear. 
This very quickly accelerates the 
vehicle and should not be used for 
normal acceleration needs.
Lock button
Button on the door which indicates 
whether the door is locked or 
unlocked. 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 SmartKey.Menu
The control system displays are 
arranged in menus. Each menu 
contains a number of commands for 
particular systems. In the Audio menu, 
for example, 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 
method. 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 
ANTI-KNOCK INDEX.Multifunction display
Display field in the instrument cluster 
used to present information provided 
by the control system.
Multifunction steering wheel
Steering wheel with buttons for 
operating the control system.
Overspeed range
Engine speeds within the red marking 
of the tachometer dial. Avoid this 
engine speed range, as it may result in 
serious 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.