Engine
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
;NThe yellow Check Engine warning lamp lights up while the engine is running.
There may be a malfunction, for example:
Rin the engine management
Rin the fuel injection system
Rin the exhaust system
Rin the ignition system (for vehicles with gasoline engines)
Rin the fuel system
The emission limit values may be exceeded and the engine may be in emergency
mode.
XVisit a qualified specialist workshop immediately.
Vehicles with a diesel engine: the fuel tank has been run dry (
Ypage 150).
XStart the engine three to four times after refueling.
If the yellow Check Engine warning lamp goes out, emergency running mode is
canceled. The vehicle need not be checked.
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 require-
ments in effect in these states. If in doubt, check whether such legal regulations
apply in the state in which you are currently driving.
8N The yellow reserve fuel warning lamp lights up while the engine is running.
The fuel level has dropped into the reserve range.
XRefuel at the nearest gas station.
8N 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.
XCheck that the fuel filler cap is correctly closed.
XIf the fuel filler cap is not correctly closed: close the fuel filler cap.
XIf the fuel filler cap is closed:visit a qualified specialist workshop.
?NThe red coolant warning lamp lights up while the engine is running and the
coolant temperature gauge is at the start of the scale.
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.
XPull 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.
XSecure the vehicle against rolling away (Ypage 153).
XConsult a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster277
On-board computer and displays
Z
Flexible Fuel vehicles
Important safety notes
GWARNIN G
Fuel is highly flammable. If you handle fuel
incorrectly, there is aris kof fir eand explo-
sion .
You must avoi dfire, open flames, creating
sparks and smoking. Switc hoff th eengin e
and ,if applicable, th eauxiliary heating before
refueling.
GWARNIN G
Fuel is poisonous and hazardous to health.
Ther eis aris kof injury.
You must mak esure that fuel does no tcome
int ocontact wit hyour skin, eyes or clothing
and that it is no tswallowed. Do no tinhale fuel
vapors. Kee pfuel away from children .
If you or other scome int ocontact wit hfuel ,
observ eth efollowing:
RWash away fuel from skin immediately
usin gsoap and water.
RIf fuel comes int ocontact wit hyour eyes,
immediately rinse them thoroughly wit h
clean water. Seek medical assistanc ewith-
out delay.
RIf fuel is swallowed, seek medical assis-
tance without delay. Do no tinduce vomit -
ing .
RImmediately chang eout of clothing whic h
has come int ocontact wit hfuel .
Flexible Fuel vehicles can be refueled wit hth e
followin gfuel types:
Rpremium-grade unleaded gasolin e
RE85fuel
Ramixtur eof E8 5fuel and premium-grade
unleaded gasolin e
iFlexible Fuel vehicles can be recognize dby
th eEthanol up to E85 sticker on theinside of
th efuel filler flap .
Fuel consump tion
The energyconten tof E8 5fuel is less than that
of th esam eamoun tof premium-grade gasoline.
The amoun tof fuel consumed when operating
th evehicl ewit hE8 5fuel is therefor ehigher than
wit hpremium-grade gasoline.
Maintenance
Infor myour authorize dMercedes-Ben zCente r
that you are operating or have operate dth e
vehicl ewit hE8 5fuel .
Low outside temperatures
If th eoutside temperature is belo w32 ‡(0 †),
the starting procedure can take noticeably lon-
ger when operating with E85 fuel.
E85 fuel is not suitable for use at outside tem-
peratures under -4 ‡ (-20 †).
DEF
Important safety notes
Comply with the important safety notes for ser-
vice products when handling DEF (Ypage 373).
DEF is a water-soluble fluid for the exhaust gas
aftertreatment of diesel engines. It is:
Rnot poisonous
Rcolorless and odorless
Rnot flammable
When you open the DEF container, small
amounts of ammonia vapor may be released.
Ammonia vapors have a pungent odor and are
particularly irritating to the skin, to mucous
membranes and to the eyes. You may experi-
ence a burning sensation in your eyes, nose and
throat. Coughing and watering of the eyes are
possible.
Do not inhale ammonia vapors. Fill the DEF tank
only in well-ventilated areas.
Low outside temperatures
DEF freezes at a temperature of approximately
12 ‡(-11 †). The vehicle is delivere dfrom th e
factory equippe dwit h a DEFpreheatin gsystem.
Winte roperation can thus be guaranteed even
at temperature sbelow 12 ‡(-11 †).
376Service pr oducts and filling capacities
Technical data