Mercedes-Benz S-CLASS 2017 Operator's Manual page 266

Warning and indicator lamps in the instrument cluster
264
Engine
Warning/
N Signal type
indicator
Possible causes/consequences and M Solutions
lamp
; N The yellow Check Engine warning lamp lights up while the engine is running.
There may be a malfunction, for example:
R
R
R
R
R
The emission limit values may be exceeded and the engine may be in emergency
mode.
X
i
8 N The yellow reserve fuel warning lamp lights up while the engine is running.
The fuel level has dropped into the reserve range.
X
8 N The yellow reserve fuel warning lamp flashes while the vehicle is in motion.
In addition, the ; Check Engine warning lamp may light up.
The fuel filler cap is not closed correctly or the fuel system is leaking.
X
X
X
? N The red coolant warning lamp comes on while the engine is running. The coolant
temperature gauge is at the beginning of the cold range.
The temperature sensor for the coolant temperature gauge is malfunctioning.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
X
X
X
in the engine management
in the fuel injection system
in the exhaust system
in the ignition system
in the fuel system
Visit a qualified specialist workshop immediately.
In some states, you must immediately visit a qualified specialist workshop as
soon as the yellow Check Engine warning lamp lights up. This is due to the legal
requirements in effect in these states. If in doubt, check whether such legal
regulations apply in the state in which you are currently driving.
Refuel at the nearest gas station.
Check that the fuel filler cap is correctly closed.
If the fuel filler cap is not correctly closed: close the fuel filler cap.
If the fuel filler cap is closed: visit a qualified specialist workshop.
Pull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions. Do not continue driving under any circumstances.
Secure the vehicle against rolling away (
Consult a qualified specialist workshop.
page 162).
Y