2018 MERCEDES-BENZ S-CLASS CABRIOLET check engine

ASSYST PLUS serv ice interval display
Fu nction of the ASS YST PLUS serv ice interval
displ ay
The ASS YST PLUS service inter val display in the
instrument display pr ovides information on the
re maining time or dis tance be fore the next
service due date.
Yo u can hidethis service message using the
back button on the left-hand side of thesteering
wheel.
Yo u can obtain fur ther information concerning
th e servicing of your vehicle from a qualified
specialist workshop, e.g. an authorized
Mercedes-Benz Center.
Displaying the service due da te
On-board computer:
,Service.ASSYST PLUS
The next service due date is displa yed.
#To exitth e displa y:press the back button
on the left-hand side of thesteering wheel. Make sure
toobser vethefo llowing fur ther rela‐
te d subjec t:
ROperating the on-board computer
(→page 209).
Car rying out maintenance workatregular
inter vals
* NO
TEPremature wearthro ugh failure to
obser veservice due dates
Service workwhich is not car ried out at the
ri ght time or incomple tely can lead to
inc reased wear and damage totheve hicle.
#Alw ays obser vethe prescribed service
inter vals.
#Alw ays ha vethe prescribed service
wo rkcar ried out at a qualified specialist
wo rkshop.
Special service requ irements
The prescribed service inter val is based on nor‐
mal operation of theve hicle. Maintenance work will need
tobe per form ed more of ten if theve hi‐
cle is operated under arduous conditions or
increased loads.
Examples of arduous operating conditions:
Rre gular city driving with frequent intermedi‐
ate stops
Rmainly short-dis tance driving
Rfrequent operation in mountainous terrain or
on poor road sur faces
Rwhen the engine is of ten le ftidling for long
periods
Roperation in particula rly dusty condition s
and/o rif air-recirculation mod eis frequentl y
used
In these or similar operating conditions, ha vethe
interior air filter, engine air cleaner, engine oil
and oil filter etc. changed more frequently. The
tires must be checked more frequently if the
ve hicle is operated under increased loads. Fur‐
th er information can be obtained at a qualified
specialist workshop.
Maintenance and care 327

Engine oil
Checkingthe engine oil le vel with the on-
board compu ter
The engine oil le vel is de term ined during driving.
The oil le vel display is only available af ter a driv‐
ing time of up to30 minutes and if the ignition is
switched on, depending on the driving profile.
It is not possible tocor rectly measure the oil
le ve l if:
Rtheve hicle is not le vel during the measure‐
ment process.
Rth e hood was pr eviously opened.
The engine must be restar ted and the engine oil
le ve l will be de term ined again when driving.
On-board computer:
,Service.Engine Oil Level
Yo u will see one of thefo llowing messa ges in
th e multifunction displa y:
#Measuring Engine Oil Level...: measurement
ofthe oil le vel is not yet possible. Repeat the
requ est af ter a maximum of 30 minutes' driv‐
ing.
#Engine Oil Level OK andthe bar display for
indicating the oil le vel in the multifunction
display is green and is between "min" and
"max": the oil le vel is cor rect.
#Engine Oil Level Add 1.0 l andthe bar display
fo r indicating the oil le vel in the multifunction
display is orange and is below "min": top up
with 1.1 US qt (1 l) of engine oil.
#Reduce Engine Oil Level andthe bar display
fo r indicating the oil le vel in the multifunction
display is orange and is abo ve"max ":drain
off theex cess engine oil. Consult a qualified
specialist workshop.
#For Engine Oil Level Switch Ignition On:
switch on the ignition tocheck the engine oil
le ve l.
#Engine Oil Level System Inoperative: sensor
defective or not connec ted. Consult a quali‐
fi ed specialist workshop.
#Engine Oil Level System Currently Unavail.:
close the hood. Ad
ding engine oil
&
WARNING Risk of burn s from hot com‐
ponent parts in the engine compartment
Cer tain component parts in the engine com‐
partment can be very hot, e.g. the engine,
th e cooler and parts of theex haust sy stem.
#Let the engine cool down and only
to uch the component parts described
as follo ws .
&
WARNING Risk offire and injury from
engine oil
If engine oil comes into con tact wi thhot
component parts in the engine compart‐
ment, it may ignite.
#Make sure that no engine oil is spilled
next tothefiller opening.
#Allow the engine tocool off and thor‐
oughly clean the engine oil from compo‐
nent parts before starting theve hicle.
Maintenance and care 331

*NO
TEEngine damage causedbyan
incor rect oil filter, incor rect oil or addi‐
tives
#Do not use engine oils or oil filters
which do not cor respond tothe specifi‐
cations explicitly prescribed forth e
service inter vals.
#Do not alter the engine oil or oil filter in
order toachie velonger change inter vals
th an prescri bed.
#Do not use additives.
#Follow the instructions in the service
inter val display rega rding the oil
ch ange.
* NO
TEDama gecaused bytopping up too
much engine oil
Ad ding too much engine oil can cause dam‐
age tothe engine or the catalytic con verter.
#Ha ve excess engine oil remo ved at a
qu alified specialist workshop.
#Tu rn cap 1counter-clockwise and remo ve
it.
#Ad d engine oil.
#Replace cap 1and turn it clockwise as far
as it will go.
#Check the oil le vel again (→page 331).
Checking coolant le vel
&
WARNING Risk of burn s from hot com‐
ponent parts in the engine compartment
Cer tain component parts in the engine com‐
partment can be very hot, e.g. the engine,
th e cooler and parts of theex haust sy stem.
#Let the engine cool down and only
to uch the component parts described
as follo ws .
&
WARNING Risk of scalding from hot
coolant
The engine cooling sy stem is pressurized,
particularly when the engine is warm. If you
open the cap, you could be scalded byhot
coolant spr aying out.
#Let the engine cool down before open‐
ing the cap.
#When opening the cap, wearglove s and
saf etygl asses.
#Open the cap slowly torelease pres‐
sure.
332 Maintenance and care

#Park theve hicle on a le vel sur face.
#Check the coolant temp erature display in the
instrument clus ter.
The coolant temp erature must be below
15 8 °F (70 °C).
#Slowly turn cap 1counter-clockwise to
re lease overpressure.
#Continue turning cap 1counter-clockwise
and remo veit.
The coolant le vel is cor rect:
Rifth e engine is cold, up tomar ker bar 2
Rifth e engine is warm, up to0.6 in (1.5 cm)
ov er mar ker bar 2
#If necessar y,top up with coolant that has
been appr ovedby Mercedes-Benz.
RFurther information on coolant (→page 400)
Ad ding washer fluid tothe windshield
wa sher sy stem
&
WARNING Risk of burn s from hot com‐
ponent parts in the engine compartment
Cer tain component parts in the engine com‐
partment can be very hot, e.g. the engine,
th e cooler and parts of theex haust sy stem.
#Let the engine cool down and only
to uch the component parts described
as follo ws .
&
WARNING Danger of burn s when open‐
ing the hood
If yo u open the hood when the engine has
ove rheated or during a fire inthe engine
compartment, you could come into contact
wit h hot gases or other escaping operating
fl uids.
#Before opening the hood, allow the
engine tocool down.
#Intheeve nt of a fire inthe engine com‐
partment, keep the hood closed and
call thefire service.
&
WARNING ‑ Risk of fire and injury from
windshield washer concentrate
Wi ndshield washer concentrate is highly
fl ammable. It could ignite if it comes into
con tact wi thhot engine component parts or
th eex haust sy stem.
#Make sure that no windshield washer
concentrate spills out next tothefiller
opening.
Maintenance and care 333

#Make surethat the positive term inal of
th e connected battery does not come
into conta ct withvehicle parts.
#Ne ver place me tal objects or tools on a
batter y.
#When connecting and disconnecting the
batter y,yo u must observ eth e descri‐
bed order forth e battery clamps.
#When giving starting assis tance, al ways
make sure that you only connect bat‐
te ry term inals with identical polarity.
#During starting assis tance, you must
observ eth e described order for con‐
necting and disconnecting the jumper
cables.
#Do not connect or disconnect the bat‐
te ry cla mp s while the engine is running.
&
WARNING Risk ofexplosion during
ch arging process and starting assis tance
During thech arging process and starting
assis tance, the battery may release an explo‐
sive gas mixture.
#Av oid fire , open flames, creating spar ks
and smoking.
#Make sure that there is suf ficient venti‐
lation du ring thech arging process and
during starting assis tance.
#Do not lean over a batter y.
Ifth e indicator/warning lamps in the instrument
clus ter do not light up at low temp eratures, it is
ve ry likely that the dischar ged battery has fro‐
zen.
& WARNING Risk ofexplosion from a fro‐
zen battery
A dischar ged battery may freeze at temp era‐
tures slightly abo veor below freezing point.
During starting assis tance or battery charg‐
ing, batte rygas may be released.
#Alw aysth aw a frozen batte ryout firs t
before charging it or per form ing start‐
ing assis tance.
The service li feof a battery that has been
th awe d may be dramatically shor tened. It is
recommended that you ha veathaw ed bat‐
te ry checked at a qualified specialist workshop.
All vehicles
* NO
TEDama gecaused bynumerous or
ex tended attem ptsto start the engine
Nume rous or extended attem ptsto start the
engine may damage the catalytic con verter
due tonon-combu sted fuel.
#Av oid numerous and extended attem pts
to start the engine.
Obser vethefo llowing points during starting
assis tance and when charging the battery:
ROnly use undamaged jumper/charging
cables with a suf ficient cross-section and
insula tedte rm inal clamps.
RNon- insulated parts of thete rm inal clamps
must not come into con tact wi thother me tal
parts while the jumper/charging cable is
connected tothe battery/jump-s tart connec‐
tion point.
Breakdown assis tance 351

Opening
&WARNING Risk of injury from usingthe
windshield wipers while the engine hood
is open
When the engine hood is open and the wind‐
shield wipers are set in motion, you can be
trapped bythe wiper linkage.
#Alw ays switch off the windshield wipers
and ignition before opening the engine
hood.
#Re lease retaining clips 1.
Pull co ver2 up.#Remo veany existing moisture from the fuse
box using a dry clo th.
#Loosen scr ews4, remo vefuse box lid 3
from theto p.
Closing
#Check whe ther the seal is positioned cor‐
re ctly in lid 3.
360
Breakdown assis tance

Engine
Display messagesPossible causes/consequences and MSolutions
Check Coolant Level See
Operator's Manual *T
he coolant le vel is too lo w.
* NO
TEEngine damage duetoinsuf ficient coolant
#Av oid long journe yswith insuf ficient coolant.
#Ad d coolant .
?
Coolant Too Hot Stop Vehi-
cle Turn Engine Off *T
he coolant is too hot.
#Pull over and stop theve hicle safely and switch off the engine, paying attention toroad and traf fic conditions.
&
WARNING Danger of burn s when opening the hood
If yo u open the hood when the engine has overheated or during a fire inthe engine compartment, you could
come into contact with hot gases or other escaping operating fluids.
#Before opening the hood, allow the engine tocool down.
#Intheeve nt of a fire inthe engine compartment, keep the hood closed and call thefire service.
#Wa it until the engine has cooled down.
#Make sure that the air supply tothera diator is not obstructed.
#Av oiding high loads on the engine, drive on tothe nearest qualified specialist workshop. In doing so, ensure that
th e coolant temp erature display remains below 248 °F (120 °C).
Display message s andwarning/indicator lamps 427

Displaymessages
Possible causes/consequences and MSolutions
#
Stop Vehicle Leave Engine
Running*T
he battery charge leve l is too low and must be charge d.
#Pull over and stop theve hicle safely as soon as possible, paying attention toroad and traf fic conditions. Do not
continue driving under any circums tances.
#Lea veengine running.
#Wa it until the display message disappears before pulling away.
4
Check Engine Oil At Next
Refue ling *T
he engine oil le vel has dropped tothe minimum le vel.
* NO
TEEngine damage causedbydriving with insuf ficient engine oil#Av oid long journe yswith insuf ficient engine oil.
#Check the engine oil le vel when next refueling.
To p up the engine oil (
→page 331).
No tes on engine oil (
→page 398).
8
Gas Cap Loose *T
here has been pressure loss in the fuel sy stem. The fuel filler cap is not closed cor rectly or the fuel sy stem is
leaking.
#Close the fuel filler cap.
#If th e fuel filler cap was already proper lyclosed: consult a qualified specialist workshop.
Display messages and warning/indicator lamps 429