2008 MERCEDES-BENZ S-Class alternator

629 Practical hints
What to do if …?
Problem
Possible cause/consequence
Suggested solution
-
The yellow Antilock
Brake System (ABS)
indicator lamp comes on
while the engine is run-
ning.
The charging voltage has fallen below
10 volts. The ABS has switched off.
The battery may not be charged sufficiently.
When the voltage is above this value again,
the ABS is operational again and the ABS in-
dicator lamp should go out.
If the ABS indicator lamp does not go out:
Have the generator (alternator) and the
battery checked.
When the voltage is above this value again,
the ABS is operational again.
;(USA only)3(Canada only)-
v
The red brake warning
lamp comes on while the
engine is running. In addi-
tion, the yellow ABS mal-
function indicator lamp,
and the yellow ESP
®
warning lamp come on
and an acoustic warning
sounds.
A malfunction in the Electronic Brake Pro-
portioning (EBP) was detected. The ABS,
BAS, ESP
® and PRE-SAFE
® are also
switched off (see messages in multifunction
display).
The brake system continues to function
normally, but without electronic support.

Continue driving with added caution.
Wheels may lock during hard braking,
reducing steering capability.

Read and observe messages in the mul-
tifunction display (
page 642).

Have the system checked at an autho-
rized Mercedes-Benz Center as soon as
possible.
Failure to follow these instructions increas-
es the risk of an accident.

663 Practical hints
What to do if …?
Display
Possible cause/consequence
Possible solution
ABS and ESP
Currently Unavailable
See Oper. Manual
ABS, ESP
® as well as PRE-SAFE
® are not
available due to a malfunction. BAS is also
switched off. It is possible that the self-diag-
nostics have not yet been completed.
The brake system still functions normally.
BAS Plus* and PRE-SAFE
® Brake* are also
not available.

Drive a short distance with gentle turns
above a speed of 12 mph (20 km/h).
The message disappears when ABS and ESP
®
are again available.
The ABS, ESP
® as well as PRE-SAFE
® were
deactivated because of insufficient power
supply. The charging voltage has fallen be-
low 10 volts.
The brake system still functions normally
but without the ABS, ESP
® and PRE-SAFE
®
available.
BAS Plus* and PRE-SAFE
® Brake* are also
not available.
When the voltage is above this value again, the
ABS, ESP
® and PRE-SAFE
® are operational again
and the message in the multifunction display
should disappear.
If the message in the multifunction display does
not disappear:

Have the generator (alternator) and the bat-
tery checked.

678 Practical hintsWhat to do if …?Display
Possible cause/consequence
Possible solution
The battery is no longer charging.
Possible causes:

alternator malfunctioning


broken poly-V-belt

Stop the vehicle immediately in a safe loca-
tion.

Engage the electronic parking brake
(page 422).

Check the poly-V-belt.
If it is broken:

Do not continue to drive. Otherwise the en-
gine will overheat due to an inoperative water
pump which may result in damage to the en-
gine.

Notify an authorized Mercedes-Benz Center.
If it is intact:

Drive immediately to the nearest authorized
Mercedes-Benz Center.
There is a malfunction in the electronic
system.

Have the system checked by an authorized
Mercedes-Benz Center as soon as possible.

750 Technical dataLayout of poly-V-belt driveS 450 4MATIC
1, S 550 and
S 550 4MATIC
1Idler pulley
2Idler pulley
3Automatic belt tensioner
4Pump for power-steering assistance
Vehicles with ABC*: ABC* tandem
pump (pump for power-steering assis-
tance and ABC* chassis)
5Air conditioning compressor
6Crankshaft
7Coolant pump
8Generator (alternator)
S63 AMG
1Idler pulley
2Idler pulley
3Idler pulley
4Automatic belt tensioner
5Pump for power-steering assistance
6Air conditioning compressor
7Crankshaft
8Coolant pump
9Generator (alternator)
S 600 and S 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
1Canada only

760 Technical dataElectrical systemModel
S 450 4MATIC
1
1Canada only
S 550
S 550 4MATIC
S 600
Generator (alternator)
14 V/220 A
14 V/220 A
14 V/220 A
Starter motor
12 V/1.7 kW
12 V/1.7 kW
12 V/1.7 kW
Starter battery
12 V/35 Ah
12 V/35 Ah
12 V/35 Ah
Electrical consumer
battery
12 V/95 Ah
12 V/95 Ah
12 V/95 Ah
Spark plugs
NGK PLKR 6A
Bosch Y 7 MPP 33
NGK PLKR 6A
Bosch Y 7 MPP 33
NGK IFR 6Q-G
Electrode gap
0.031 in (0.8 mm)
0.031 in (0.8 mm)
0.028 in (0.7 mm)
Tightening torque
15 – 18 lb-ft (20 – 25 Nm)
15 – 18 lb-ft (20 – 25 Nm)
18 – 22 lb-ft (25 – 30 Nm)

761 Technical data
Electrical system
Model
S63 AMG
S65 AMG
Generator (alternator)
14 V/220 A
14 V/220 A
Starter motor
12 V/2.1 kW
12 V/1.7 kW
Starter battery
12 V/35 Ah
12 V/35 Ah
Electrical consumer
battery
12 V/95 Ah
12 V/95 Ah
Spark plugs
–1
1Contact an authorized Mercedes-Benz Center
NGK IFR 6Q-G
Electrode gap
0.039 in (1.0 mm)
0.028 in (0.7 mm)
Tightening torque
15 – 18 lb-ft (20 – 25 Nm)
15 – 22 lb-ft (20 – 30 Nm)