Mercedes-Benz S-Class Owner's Manual page 607

Warning/indicator lamp Possible causes/consequences and
Engine diagnosis warning Vehicles with a diesel engine: the fuel tank may have been run dry.
lamp
Start the engine three to four times after refuelling.
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If the yellow engine diagnosis warning lamp goes out, emergency operation mode is cancelled. The vehicle need not
be checked.
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The red electrical fault warning lamp is lit.
There is a fault in the electrics.
Observe the messages on the multifunction display.
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Electrical fault warning
lamp
8
The yellow fuel reserve warning lamp is lit while the engine is running.
The fuel supply has dropped into the reserve range.
Refuel.
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Fuel reserve warning lamp
?
The red coolant warning lamp is lit while the engine is running.
Possible causes:
The temperature sensor is malfunctioning
R
Coolant warning lamp
The coolant level is too low
R
The air supply to the radiator is obstructed
R
The radiator fan is faulty
R
If there is an additional warning tone, the coolant temperature has exceeded 120 °C.
Display messages and warning/indicator lamps 605
M M Solutions