lock MERCEDES-BENZ C-CLASS COUPE 2021 Repair Manual

Proportion of antifreeze concentrate in
the
engine cooling sy stem:
R a minimum of 50% (antifreeze pr otection
down toappr oximately -37°C)
R a maximum of 55% (antifreeze pr otection
down to-45°C) Note
s on windscreen washer fluid Obser
vethe no tes on operating fluids
(/ page 420). &
WARNING ‑ Risk of fire and injury due to
windscreen washer concentrate
Wi ndsc reen 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 windsc reen washer
concentrate spills out next tothefiller
opening. *
NO
TEDama getotheex terior lighting
due tounsuitable windsc reen washer
fl uid Uns
uitable windsc reen washer fluids may
damage the plastic sur face of theex terior
lighting. #
Only use windscreen washer fluids
which are also suitable for use on plas‐
tic sur faces, e.g. MB SummerFit or MB
Wi nterFit. *
NO
TEBlocked spr aynozzles caused by
mixing windscreen washer fluids #
Do not mix MB SummerFit and MB Win‐
te rFit with other windscreen washer flu‐
ids. Do not use distilled or de-ionised
water.Other‐
wise, thefill le vel sensor may be triggered er ro‐
neously.
Re commended windscreen washer fluid:
R abo vefreezing point: e.g. MB SummerFit
R below freezing point: e.g. MB WinterFit Fo
rth e cor rect mixing ratio, referto the informa‐
tion on the antif reeze conta iner.
Mix washer fluid with windsc reen washer fluid all
ye ar round. Ve
hicle data Ve
hicle dimensions The heights speci
fied may vary as a result of the
fo llowing factors:
R tyres
R load
R condition of the suspension
R optional equipment Te
ch nical da ta429

Display messages
Possible causes/consequences and M
MSolutions
Á Key not detected (red dis‐
play message) *T
hekey cannot be de tected and may no longer be in theve hicle.
The key is no lon ger in theve hicle and you swit choff the engine:
R You can no lon gerst art the engine.
R You cannot centrally lock theve hicle. #
Ensure that theke y is in theve hicle.
If th eke y de tection function has a malfunction due toast ro ng radio signal source: #
Stop theve hicle immediately in accordance with the traf fic conditions. #
Place theke y in the slot forst arting the engine with theke y (/ page146).
Place the key in the
marked space See Owner's
Manual *K
eydetection is malfunctioning. #
Change the location of theke y in theve hicle. #
Place theke y in the slot forst arting the engine with theke y (/ page146). 438
Displaymessa ges and warning/indicator lamps

Ve
hicle Display messages
Possible causes/consequences and M
MSolutions
d Vehicle is operational
Switch off ignition before
exiting *Y
ou are leaving theve hicle in a ready-to-drive state. #
When you lea vetheve hicle, switch off the ignition, secure theve hicle against rolling away and take theke y with
yo u. #
Ifyo u do not lea vetheve hicle, switch off the electrical consumers, e.g. the seat heating. Otherwise, the12 ‑V
battery may discharge and starting the engine may be possible only with the help of a second battery (jump
st art).
ï
Check trailer hitch lock *T
he trailer hitch is not operational during a journey with a trailer. &
WARNING Risk of an accident if the ball neck is not loc ked
The trailer may become de tach ed. #
Stop theve hicle immediately in accordance with the traf fic conditions. Do not continue driving. #
Uncouple the trailer and secure it against rolling away. #
Initiate a new swivel mo vement and do not re-couple the trailer until thewa rning/indicator lamp goes out. #
Initiate a new swivel mo vement (/ page 227). #
When the display message disappears, couple up the trailer and drive on.
If th e display message does not disappear, the trailer hitch is malfunctioning and the ball neck is not loc ked. Display messages and
warning/indicator lamps 443

Display messages
Possible causes/consequences and M
MSolutions #
Do not couple up the trailer. Drive on without the trailer. No tethere duced ground clearance due tothe
unlo cked ball nec k. #
Consult a qualified specialist workshop.
*T he trailer hitch will not be operational when theve hicle is stationar y. #
Uncouple the coupled trailer and secure it against rolling away. #
Ifth e ball neck has been folded in: unlockthe ball neck (/ page 227). #
Swivel the ball neck into the end position manually and let it engage. #
Ifth e ball neck has been folded out: unlockthe ball neck (/ page 227). #
Swivel the ball neck beneath the bumper manually and let it engage.
If th e display message does not disappear, the trailer hitch is malfunctioning and the ball neck is not loc ked. #
Do not couple up the trailer. Drive on without the trailer. No tethere duced ground clearance due tothe
unlo cked ball nec k. #
Consult a qualified specialist workshop.
Ù Steering malfunction
Increased physical effort
See Owner's Manual *T
he po werst eering assis tance is malfunctioning. &
WARNING Risk of an accident due toaltered steering characteristics
If th e po wer assi stance of thesteering fails partially or comple tely, you will need touse more forc eto steer. #
If safe steering is possible, drive on carefully. 444
Displaymessa ges and warning/indicator lamps

Display messages
Possible causes/consequences and M
MSolutions #
Visit or consult a qualified specialist workshop immediatel y. Ù
Steering malfunction Stop
immediately See Owner's
Manual *T
hesteering is malfunctioning. Steering capability is significant lyimpaired. &
WARNING Risk of accident if steering capability is impaired
If th esteering does not function as intended, theve hicle's operating saf ety is jeopardised. #
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. #
Consult a qualified specialist workshop. Active bonnet malfunction
See Owner's Manual
*T
he active bonnet (pedestrian pr otection) is malfunctioning or inoperative af ter having already been triggered. #
Consult a qualified specialist workshop.
C *A
t least one door is open. #
Close all doors.
M *T
he bonnet is open. &
WARNING Risk of accident due todriving with the bonn etunlo cked
The bonn etmay open and block your vie w. Displ
aymessa ges and warning/indicator lamps 445

Display messages
Possible causes/consequences and M
MSolutions #
Neverre lease the bonn etwhen driving. #
Before every trip, ensure that the engine bonn etis loc ked. #
Stop theve hicle immediately in accordance with the traf fic conditions. #
Close the bonn et.
N *T
he boot lid is open. &
DANG ER Risk of exhaust gas poisoning
Combustion engines emit poisonous exhaust gases such as carbon monoxide. Exhaust gases can enter the
ve hicle interior if the boot lid is open when the engine is running, especially if theve hicle is in motion. #
Alw ays switch off the engine before opening the boot lid. #
Never drive with the boot lid open. #
Close the boot lid.
_ Rear left seat backrest not
locked (Example) *T
he seat backrest of the cor responding seat is not engaged. #
Foldthe seat backrest back until it engages. 446
Displaymessa ges and warning/indicator lamps

Display messages
Possible causes/consequences and M
MSolutions
_ Front left seat backrest not
locked (examp le) *T
he seat backrest of the cor responding front seat is not engaged. #
Foldthe seat backrest back until it engages.
¥ Top up washer fluid *T
hewasher fluid le vel in thewa sher fluid reser voir has dropped below the minimum. #
Top up thewa sher fluid (/ page 368). Engine
Display messages
Possible causes/consequences and M MSolutions
To switch off the engine,
press Start/Stop button
for at least 3 seconds or 3
times. *Y
ou ha vepressed thest art/ stop button while theve hicle is in motion. #
Information about switching off the engine while driving (/ page145). Displ
aymessa ges and warning/indicator lamps 447

Driving saf
ety sy stems Display messages
Possible causes/consequences and M
MSolutions
!
÷ currently unavailable See
Owner's Manual *
ABS and ESP ®
are temp orarily una vailable.
Other driving sy stems and driving saf ety sy stems (e.g. BAS) may also be temp orarily una vailable.
The brake sy stem will continue tooperate normally. Braking dis tance may increase in an emergency braking situa‐
tion. &
WARNING Risk of skidding if ABS and ESP ®
are malfunctioning
The wheels may lock du ring braking and ESP ®
does not pe rform any vehicle stabilisation.
The steerability and braking characteristics are heavily impaired and the braking dis tance may increase. In addi‐
tion, other driving saf ety sy stems are switched off. #
Drive carefully on a suitable stre tch of road, making slight steering mo vements at a speed abo ve30 km/h. #
Ifth e display message does not disappear, consult a qualified specialist workshop immediately. Drive care‐
full y. Displ
aymessa ges and warning/indicator lamps 469

Display messages
Possible causes/consequences and M
MSolutions
!
÷ inoperative See Owner's
Manual *
ABS and ESP ®
are malfunctioning.
Other driving sy stems and driving saf ety sy stems (e.g. BAS) may also be malfunctioning.
The brake sy stem will continue tooperate normally. Braking dis tance may increase in an emergency braking situa‐
tion. &
WARNING Risk of skidding if ABS and ESP ®
are malfunctioning
The wheels may block du ring braking and ESP ®
does not pe rform any vehicle stabilization.
The steerability and braking characteristics are heavily impaired and the braking dis tance may increase. In addi‐
tion, other driving saf ety sy stems are switched off. #
Drive on carefull y. #
Have ABS and ESP ®
ch ecked immediately at a qualified specialist workshop. ÷
currently unavailable See
Owner's Manual *
ESP ®
is temp orarily una vailable.
Other driving sy stems and driving saf ety sy stems (e.g. BAS) may also be malfunctioning. &
WARNING Risk of skidding if ESP is malfunctioning ®
If ESP ®
is malfunctioning, ESP ®
cannot car ryout vehicle stabilisation. In addition, other driving saf ety sy stems
are switched off. #
Drive carefully on a suitable stre tch of road, making slight steering mo vements at a speed abo ve30 km/h. 47 0
Displaymessa ges and warning/indicator lamps

Display messages
Possible causes/consequences and M
MSolutions
T
!
÷ inoperative See Owner's
Manual *
EBD, ABS and ESP ®
are malfunctioning.
Other driving sy stems and driving saf ety sy stems (e.g. BAS) may also be malfunctioning. &
WARNING Risk of skidding if EBD, ABS and ESP ®
are malfunctioning
The wheels may block du ring braking and ESP ®
does not pe rform any vehicle stabilization.
The steerability and braking characteristics are heavily impaired and the braking dis tance may increase. In addi‐
tion, other driving saf ety sy stems are switched off. #
Drive on carefull y. #
Have the brake sy stem checked immediately at a qualified specialist workshop. Active Brake Assist Func-
tions currently limited See
Owner's Manual *
Ve hicles with the Driving Assistance Package: Active Brake Assi stwith cross-traf fic function, Evasi veSteering
Assist or PRE‑SAFE ®
PLUS are temp orarily una vailable or only partially available.
Ve hicles without the Driving Assistance Package: Active Brake Assi stistemp orarily una vailable. #
Drive on.
As soon as the ambient conditions are within the sy stem limits, the sy stem will become available again. #
Ifth e display message does not disappear, stop theve hicle in accordance with the tra ffic conditions and restart
th e engine. 472
Displaymessa ges and warning/indicator lamps