Page 415 of 585

414 Practical hintsWhat to do if …Lamps in instrument clusterGeneral information:
If any of the following lamps in the instru-
ment cluster fails to come on during thebulb self-check when switching on the 
ignition, have the respective bulb checked 
and replaced if necessary.Problem
Possible cause/consequence
Suggested solution
-
The yellow ABS indicator lamp 
comes on while the engine is 
running.
ABS has detected a malfunction and has 
switched off. The BAS, ESP
®, EBP and 4-ETS 
are also switched off (see messages in multi-
function display).
The brake system is still functioning normally 
but without the ABS available.
If the ABS control unit is malfunctioning, 
other systems such as the navigation 
system* or the automatic transmission may 
also be malfunctioning.
Continue driving with added caution. 
Wheels may lock during hard braking, 
reducing steering capability.
Read and observe messages in the 
multifunction display (
page 428).
Have the system checked at an 
authorized Mercedes-Benz Light 
Truck Center as soon as possible.
Failure to follow these instructions 
increases the risk of an accident.
The charging voltage has fallen below 
10 volts. The ABS has switched off.
The battery might not be charged sufficiently.
When the voltage is above this value 
again, the ABS is operational again and 
the ABS indicator lamp should go out.
If the ABS indicator lamp should go out:
Have the generator (alternator) and 
the battery checked. 
         
        
        
     
        
        Page 431 of 585

430 Practical hintsWhat to do if …Text messagesDisplay message
Possible cause/consequence
Possible solution
ABS
inoperative
See Operator’s Manual
The ABS has detected a malfunction 
and has switched off.
The ESP
® and the BAS are also 
deactivated.
The brake system is still functioning 
normally but without the ABS avail-
able.
Continue driving with added caution. 
Wheels may lock during hard braking, 
reducing steering capability.
Have the system checked at an authorized 
Mercedes-Benz Light Truck Center as soon 
as possible.
Failure to follow these instructions increases 
the risk of accident.
unavailable
See Operator’s Manual
The ABS was deactivated because of 
insufficient power supply. The charg-
ing voltage has fallen below 10 volts.
The brake system is still functioning 
normally but without the ABS 
available.
When the voltage is above this value again, the 
ABS is 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 
battery checked. 
         
        
        
     
        
        Page 438 of 585

437 Practical hints
What to do if …
Display message
Possible cause/consequence
Possible solution
ESP
unavailable
See Operator’s Manual
The ESP
® was deactivated because 
of insufficient power supply. The 
charging voltage has fallen below 
10 volts.
The brake system is still functioning 
normally but without the ABS 
available.
When the voltage is above this value again, the 
ABS is 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 
battery checked.
If the yellow ESP
® warning 
lampv flashes while driving and 
this message appears, the electron-
ic traction system has switched off 
to prevent overheating of the drive 
wheel brakes.
As soon as the brakes have cooled off, the 
electronic traction system switches on again.
The message in the multifunction display disap-
pears and the ESP
® warning lampv goes 
out.
The self-diagnosis has not been 
completed yet.
The display will clear after driving a short 
distance at a vehicle speed of above 
12 mph (20 km/h). 
         
        
        
     
        
        Page 447 of 585
446 Practical hintsWhat to do if …Symbol messagesDisplay symbol
Display messages
Possible cause/consequence
Possible 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 capability. 
Considerably greater brake pedal 
force is required and the stopping dis-
tance is increased.
Stop the vehicle in a safe location or as 
soon as it is safe to do so.
Apply the parking brake (
page 65).
 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 Light Truck Center.
If it is intact:
Drive immediately to the nearest 
authorized Mercedes-Benz Light Truck 
Center. Adjust driving to be consistent 
with reduced braking responsiveness. 
         
        
        
     
        
        Page 448 of 585
447 Practical hints
What to do if …
Display symbol
Display message
Possible cause/consequence
Possible solution
#
Battery/Alternator
Stop vehicle
The battery is defective.
Stop the vehicle in a safe location or as 
soon as it is safe to do so.
Apply the parking brake (
page 65).
Do not continue to drive.
Notify an authorized Mercedes-Benz 
Light Truck Center.
y
inoperative
Downhill Speed Regulation is 
malfunctioning.
Have the Downhill Speed Regulation 
checked by an authorized Mercedes-Benz 
Light Truck Center.
2
Brake wear
The brake pads have reached 
their wear limit.
Have the brake pads replaced as soon as 
possible.
!
Brake pad thickness must be visually in-
spected by a qualified technician at the intervals 
specified in the Maintenance Booklet. 
         
        
        
     
        
        Page 510 of 585

509 Practical hints
Battery
Disconnecting, removing, reinstalling and reconnecting the battery
Step 1 (Disconnecting)
Set the automatic transmission to 
positionP (
page 187).
Firmly depress the parking brake 
(page 65).
Turn off the engine (
page 66).
Leave the ignition switched on 
(page 40).
!
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 
authorized Mercedes-Benz Light Truck Center.
Contact your authorized Mercedes-Benz Light 
Truck 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.
Warning!
G
Disconnecting, removing, reinstalling and 
reconnecting the battery is a complicated 
and technically demanding procedure that 
also requires safety precautions to avoid the 
risk of injury. We strongly recommend that it 
be performed by a qualified technician or an 
authorized Mercedes-Benz Light Truck 
Center only. Please read the instructions 
fully before beginning operation and only 
undertake it if you feel fully capable of 
performing all of the tasks involved as de-
scribed in these instructions. Observe all 
safety instructions and precautions when 
handling automotive batteries 
(page 507). Performing the tasks involved 
incorrectly can cause damage to the vehicle 
and impair the operating safety of the 
vehicle, and/or cause severe injury to you 
or others.
i
With a disconnected battery you will no 
longer be able to turn the SmartKey in the starter 
switch and pressing the KEYLESS-GO* 
start/stop button will have no effect.
i
If your battery is discharged, the vehicle 
must be jump started (
page 515) using the 
jump start contacts in the engine compartment, 
or an accessory battery charge unit* approved 
by Mercedes-Benz must be connected using the 
jump start contacts in the engine compartment 
(see separate instructions for the accessory bat-
tery charge unit*) before any of the following 
steps can be performed. If the battery cannot be 
jumped or charged, please contact an 
authorized Mercedes-Benz Light Truck Center.
 
         
        
        
     
        
        Page 533 of 585
532 Technical dataLayout of poly-V-belt driveML 350
1Idler pulley
2Idler pulley
3Automatic belt tensioner
4Power steering pump
5Air conditioning compressor
6Crankshaft
7Coolant pump
8Generator (alternator)
ML 320 CDI
1Coolant pump
2Idler pulley
3Automatic belt tensioner
4Power steering pump
5Air conditioning compressor
6Crankshaft
7Idler pulley
8Generator (alternator)
ML 500
1Automatic belt tensioner
2Power steering pump
3Air conditioning compressor
4Crankshaft
5Coolant pump
6Generator (alternator)
7Idler pulley 
         
        
        
     
        
        Page 534 of 585
533 Technical data
Layout of poly-V-belt drive
ML 63 AMG
1Idler pulley
2Idler pulley
3Idler pulley
4Automatic belt tensioner
5Power steering pump
6Air conditioning compressor
7Crankshaft
8Coolant pump
9Generator (alternator)