Page 379 of 481
378 Practical hints
What to do if …?
Symbol messages
Display symbolDisplay messagePossible cause/consequencePossible solution
#The battery is no longer charging.
Possible causes:
broken poly-V-belt
alternator malfunctioning
Stop immediately in a safe location or
as soon as it is safe to do so 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.
Low voltage
Charge batteryThe battery has insufficient voltage.Start the engine (page 50).
Low voltage
Switch off
consumersThe battery has insufficient voltage.Turn off unnecessary electrical con-
sumers.
Page 422 of 481

421 Practical hints
Battery
Battery
The battery is located in the engine
compartment on the right hand side.
1Clamps
Removing filter box:
Release clamps1.
Remove filter box.
Installing filter box:
Insert filter box properly.
Secure it with clamps1.
Warning!G
Failure to follow these instructions can re-
sult in severe injury or death.
Observe all safety instructions and
precautions when handling automotive
batteries (
page 311).
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 terminal
clamps while the engine is running or the
SmartKey is in the starter switch. Otherwise the
alternator and other electronic components
could be severely damaged.
Have the battery checked regularly by an autho-
rized Mercedes-Benz Center.
Refer to Maintenance Booklet for maintenance
intervals or contact an authorized
Mercedes-Benz Center for further information.
Page 441 of 481
440 Technical data
Layout of poly-V-belt drive
CLK 350/CLK 550
1Idler pulley
2Idler pulley
3Automatic belt tensioner
4Power steering pump
5Air conditioning compressor
6Crankshaft
7Coolant pump
8Generator (alternator)
Page 447 of 481
446 Technical data
Electrical system
ModelCLK 350CLK 550
Generator (alternator)14 V/150 A14 V/180 A
Starter motor14 V/1.4 KW14 V/1.7 KW
Battery12 V/100 Ah12 V/100 Ah
Spark plugsBosch Platin Y 7 MPP 33
NGK PLKR 6ABosch F8 DPP 332
NGK PFR 5R-11
Electrode gap0.031 in (0.8 mm)0.039 in (1.00 mm)
Tightening torque15 - 22 lb-ft (20 - 30 Nm)18.5 - 22 lb-ft (25 - 30 Nm)