376 Practical hints
What to do if …
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Left displayRight displayPossible cause/consequencePossible solution
# The battery is no longer charging.
Possible causes:
alternator malfunctioning
broken poly-V-belt
Do not forget that the brake system
requires electrical energy and may
be operating with restricted capa-
bility. Considerably greater brake
pedal force is required and the stop-
ping distance is increased.
Stop the vehicle immediately in a safe loca-
tion 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. Contact an authorized
Mercedes-Benz Center.
If it is in order:
Contact an authorized Mercedes-Benz
Center immediately. Adjust driving to be
consistent with reduced braking respon-
siveness.
There is a malfunction in the elec-
tronic system.Have the system checked at an authorized
Mercedes-Benz Center as soon as possible.
446 Technical data
Layout of poly-V-belt drive
SL 550
1Idler pulley
2Idler pulley
3Automatic belt tensioner
4ABC tandem pump (pump for
power-steering assistance and ABC
chassis)
5Air conditioning compressor
6Crankshaft
7Coolant pump
8Generator (alternator)SL 55 AMG
The SL 55 AMG has two poly-V-belts (belt
one shown in purple/belt two shown in
black).
1Idler pulley
2Automatic belt tensioner
3ABC tandem pump (pump for
power-steering assistance and ABC
chassis)
4Air conditioning compressor
5Crankshaft
6Coolant pump
7Generator (alternator)
8Idler pulley
9Automatic belt tensioner
aSupercharger
SL 600, SL 65 AMG
1Automatic belt tensioner
2ABC tandem pump (pump for
power-steering assistance and ABC
chassis)
3Air conditioning compressor
4Crankshaft
5Coolant pump
6Generator (alternator)
7Idler pulley
8Idler pulley
9Idler pulley