light MERCEDES-BENZ C-CLASS CABRIOLET 2021 Repair Manual

R
The vehicle is secured with the electric park‐
ing brake.
In thefo llowing situations, theve hicle is held by
transmission position jand/or bythe electric
parking brake:
R The seat belt is unfas tened and the driver's
door is opened.
R The vehicle is switched off.
R There is a malfunction in the sy stem or the
po we r supp lyis insuf ficient. Fu
nction of Hill Start Assist Hill
Start Assist holds theve hicle for a short
time when pulling away on a hill under thefo l‐
lowing conditions:
R The transmission is in position hork.
R The elect ric pa rking brake is released.
This gives you enough time tomo veyour foot
from the brake pedal tothe accelerator pedal
and depress it before theve hicle begins toroll
aw ay. &
WARNING Risk of accident and inju ry
due totheve hicle rolling away
Af ter a short time, Hill Start Assist no lon ger
holds theve hicle. #
Swiftly mo veyour foot from the brake
pedal tothe accelera tor pedal. Do not
lea vetheve hicle when it is being held
by Hill Start Assist. Fu
nction of Adaptive Brake Lights Ad
aptive Brake Lights warnfollowing traf fic in an
emergency braking situation wi th thefo llowing
actions:
R Byflashing the brake lamps
R By activating the hazard warning lights
If th eve hicle is braked sharply from speeds
abo ve50 km/h, the brake lamps flash rapidl y.
This pr ovides traf fic tr avelling behind you with an
ev en more noticeable warning.
If th eve hicle is tr avelling at speeds of more than
70 km/h at the beginning of the brake applica‐
tion, the hazard warning lights switch on once th
eve hicle is stationar y.When you pull away
again, the hazard warning lights will switch off
automatically at appr oximately 10km/h. Yo u
can also switch off the hazard warning lights
using the hazard warning button. AT
TENTION ASSI ST Fu
nction of ATTENTION ASSI ST
AT TENTION ASSIST assists you on long, mon oto‐
nous jou rney s, e.g. on mo torw ays and trunk
ro ads. If ATTENTION ASSIST de tects indicators
of fatigue or increasing lapses in concentration
on the part of the driver, it suggests taking a
brea k.
AT TENTION ASSIST is only an aid. It cannot
alw ays de tect fatigue or lapses in concentration
in time. The sy stem is not a substitute for a well-
re sted and attentive driver. On long journe ys,
ta ke regular breaks in good time that allow for
adequate recuperation.
Yo u can choose between two settings:
R Standard: normal sy stem sensitivity. 174
Driving and pa rking

R
Ifyo u unfas tenyo ur seat belt and open the
driver's door (e.g. tochange drivers or take a
break).
Setting ATTENTION ASSI ST
Multimedia sy stem:
4 Vehicle 5
k Assistance
5 ATTENTION ASSIST
Setting options #
Select Standard, SensitiveorOff.
Suggesting a rest area #
Select Suggest rest area .#
Activate Oor deacti vate the function ª.
If AT TENTION ASSIST de tects fatigue or
increasing la ckof attention, it suggests a
re st area in the vicinit y. #
Select a sugges tedre st area: you are gui‐
ded tothe selected rest area. Cruise cont
rol and limiter Fu
nction of cruise control
Cruise cont rolre gulates the speed totheva lue
selec tedby the driver.
If yo u accelerate toove rtake, forex ample, the
st ored speed is not dele ted. If youre mo veyour
fo ot from the accelerator pedal af terove rtaking,
cruise control will resume speed regulation back
to thestored speed.
Yo u can store any speed abo ve20 km/h up to
th e maximum design speed or up tothe set win‐
te r tyre limit.
Obser vethe no tes on driving sy stems and your
re sponsibility; you may otherwise failto recog‐
nise dangers (/ page 168).
Me rcedes‑AMG vehicles: cruise control is avail‐
able up toa maximum speed of 250 km/h.
Displ ays on the multifunction display
R h (gre y): cruise cont rol is selec ted but
not yet acti vated.
R h (green): cruise control is active. A
stored speed appears along with theh dis‐
pla y.
% The segments extending from the cur rent
st ored speed tothe end of the scale, or to
th e set winter tyre limit, light up in the
speedome ter.
Sy stem limits
Cruise control may be unable tomaintain the
st ored speed on uphill gradients. The stored
speed is resumed when the gradient evens out.
Change into a lo werge ar in good time on long
and steep downhill gradients. Take particular
no te ofthis when driving a laden vehicle. By
doing so, you will make use of the engine's brak‐
ing ef fect. This relie vesth e load on the brake
sy stem and pr events the brakes from overheat‐
ing and wearing tooqu ickl y.
Do not use cruise control in thefo llowing situa‐
tions:
R In traf fic situations whi chrequ ire frequent
ch anges of speed, e.g. in heavy traf fic, on
winding roads. 176
Driving and pa rking

R
On slippery roads. Accelerating can cause
th e drive wheels tolose traction and the
ve hicle could then skid.
R Ifyo u are driving when visibility is poor.
Fu nction of the limiter
The limiter restricts the speed of theve hicle. To
re duce the speed tothe set speed, the limiter
applies the brakes automaticall y.
Yo u can limit the speed as follo ws:
R Variable: for a short-term speed restriction,
e.g. in built-up areas
R Perm anen t:for a longer-term speed restric‐
tion, e.g. in winter tyre mode
Yo u can store any speed abo ve20 km/h up to
th e maximum design speed or up tothe set win‐
te r tyre limit. You can also per form settings
while theve hicle is stationary if theve hicle has
been star ted.
Obser vethe no tes on driving sy stems and your
re sponsibility; you may otherwise failto recog‐
nise dangers (/ page 168).
Me rcedes‑AMG vehicles: the limiter is available
up toa maximum speed of 250 km/h. Displ
ays on the multifunction display
R È (gre y): variable limiter is selec ted but
not yet acti vated.
R È (flashes gr ey):va riable limiter is temp o‐
ra rily passive.
R È (green): variable limiter is activated.
A stored speed appears along with theÈ dis‐
pla y.The segments in the speedome ter light up,
up tothe cur rently stored speed.
If yo u depress the accelera tor pedal be yond the
pressure point (kickdown), theva riable limiter
swit ches topassive mode. The Limiter passive
message appears in the multifunctional display
and theÈ display flashes.
The variable limiter is reactivated in thefo llowing
situations:
R Ifth eve hicle speed drops below thestored
speed.
R Ifth estored speed is called up.
R Ifyo ustore a new speed. Operating cruise control or
theva riable lim‐
iter &
WARNING Risk of accident due tostored
speed
If yo u call up thestored speed and this is
lo we rth an your cur rent speed, theve hicle
decelerates. #
Take into account the tra ffic situation
before calling up thestored speed. Re
quirements:
Cruise control
R Cruise control is selected.
R ESP ®
must be activated, but not inter vening.
R The vehicle speed is at least 20 km/h.
R The transmission is in position h.
Va riable limiter
R The variable limiter is selec ted. Driving and parking
17 7

onds. If a critical situation is de
tected when driv‐
ing off, a visual and acoustic warning is given
indicating that the driver must now take control
of theve hicle. The vehicle is not accelerated any
fur ther.
Obser vethe no tes on driving sy stems and your
re sponsibility; you may otherwise failto recog‐
nise dangers (/ page 168). Ac
tive Di stance Assist DISTRO NIC displaysin
th e instrument clus ter Assi
stant display
1 Route-based speed adap tation: type of route
eve nt (/ page 184)
2 Vehicle in front
3 Distance indica tor
4 Set specified di stance
Pe rm anent status display of Active Di stance
Assist DIST RONIC
R k (white):Ac tive Dis tance Assi st
DISTRONIC selected, speci fied dis tance set R
k (whitevehicle, green speedome ter):
Ac tive Dis tance Assi stDISTRONIC acti ve,
specified dis tance set and vehicle de tected
R k (green): Active Dis tance Assi st
DISTRONIC acti ve, specified dis tance set and
ve hicle de tected
R r: Route-based speed adap tation acti ve
( / page 184).
The stored speed is shown along with the per‐
manent status display and highlighted on the
speedome ter.When Active Dis tance Assi st
DISTRONIC is passi ve,th e speed is gr eyed out.
% On mo torw ays or high-speed major roads,
th e green çvehicle symbol is displa yed
cyclically when theve hicle is ready topull
aw ay.
% Ifyo u depress the accelerator pedal be yond
th e setting of theAc tive Dis tance Assi st
DISTRONIC, the sy stem is switched topas‐
sive mode. The çsuspended message
appears in the multifunction displa y.18 0
Driving and pa rking

Display on
the speedome ter
The stored speed is highlighted on the speedom‐
et er. If the speed of theve hicle in front or the
speed adjustment forth ero ute event ahead is
less than thestored speed, the segments in the
speedome ter light up. The multifunction display
sho ws th e deactivation of Active Dis tance Assi st
DISTRONIC, as well as alterations tothe speed
due tomanual or auto matic adoption of the max‐
imum permissible speed.
Sy stem limits
The sy stem may be impaired or may not function
in thefo llowing situations, forex ample:
R In sn ow,ra in, fog, heavy spr ay, if there is
gl are, in direct sunlight or in greatlyvarying
light conditions.
R The windsc reen in the area of the camera is
dirty, mis ted up, damaged or co vered.
R Ifth era dar sensors are dirty or co vered.
R In multi- stor ey car pa rks or on roads with
st eep uphill or downhill gradients.
R Ifth ere are nar rowvehicles in front, such as
bicycles or mo torcyc les. In addition, on slippery
roads, braking or accel‐
erating can cause one or se veral wheels tolose
traction and theve hicle could then skid.
Do not use Active Dis tance Assi stDISTRONIC in
th ese situations. &
WARNING Risk of accident from acceler‐
ation or braking byActive Dis tance
Assi stDISTRONIC
Ac tive Dis tance Assi stDISTRONIC may accel‐
erate or brake in thefo llowing cases, for
ex ample:
R Ifth eve hicle pulls away using Active Dis‐
ta nce Assi stDISTRONIC.
R Ifth estored speed is called up and is
considerably faster or slo werth an the
cur rently driven speed.
R IfAc tive Dis tance Assi stDISTRONIC no
longer de tects a vehicle in front or does
not react toreleva nt objects. #
Alw ays carefully obser vethe traf fic con‐
ditions and be ready tobrake at all
times. #
Take into account the tra ffic situation
before calling up thestored speed. &
WARNING Risk of accident due toinsuf‐
fi cient decele ration byActive Dis tance
Assi stDISTRONIC
Ac tive Dis tance Assi stDISTRONIC brakes
yo ur vehicle with up to50% of the possible
deceleration. If this decele ration is not su ffi‐
cient, Active Dis tance Assi stDISTRONIC
alerts you with a visual and acoustic warning. #
Adjust your speed and main tain a suita‐
ble dis tance from theve hicle in front. #
Brake theve hicle yourself and/or take
ev asive action. Driving and parking
181

Also,
the speed is reduced if the turn signal indi‐
cator tochange lanes is swit ched on and one of
th efo llowing situations is de tected:
R Turning off at junctions
R Driving on slowing-down lanes
R Driving on lanes adjacent toslowing-down
lanes
The driver is responsible forch oosing theright
speed and observing other road users. This
applies in particular tojunctions, roundabouts
and traf fic lights, as route-based speed adap ta‐
tion does not brake theve hicle toast andstill.
When route guidance is active, thefirs t speed
adjustment is car ried out automaticall y.Ifthe
turn signal indica tor is switched on, the selected
ro ute is confirmed and fur ther speed adjustment
is activated.
Speed adap tation is cancelled in thefo llowing
cases:
R Ifth e turn signal indicator is switched off
before thero ute event.
R Ifth e driver depresses the accelerator or
brake pedal during the process. Sy
stem limits
Ro ute-based speed adap tation does not take
ri ght of wayre gulations into account. The driver
is responsible for complying with road traf fic
re gulations and driving at a suitable speed.
The speed adap tation made bythe sy stem may
not alw ays be suitable, particular lyin thefo llow‐
ing situations:
R thero ad's course not clear lyvisible
R road nar rowing
R varying maximum permissible speeds in indi‐
vidual lanes, forex ample at tollst ations
R wetro ad sur faces, snow or ice
R when towing a trailer
In these situations the driver must inter vene
acco rding ly. &
WARNING Risk of accident in spi teof
ro ute-based speed adap tation
Ro ute-based speed adap tation can malfunc‐
tion or be temp orarily una vailable in thefo l‐
lowing situations: R
Ifth e driver does not follow the calcula‐
te dro ute
R If map data is not up-to-date or available
R Intheeve nt of roadwor ks
R In bad weather or road conditions
R Ifth e accelera tor pedal is depressed
R Intheeve nt of electronical lydispla yed
speed limitations #
Adapt the speed tothe traf fic situation. Setting
route-based speed adjustment
Re quirements:
R Active Dis tance Assi stDISTRONIC is acti va‐
te d.
Multimedia sy stem:
4 Vehicle 5
k Assistance
5 Speed adjustment #
Activate Oor deacti vate ª the function. Driving and parking
18 5

R
Depending on the count ry:th e driver
presses a steering wheel button or operates
To uch Control
If Ac tive Steering Assist de tects that a sy stem
limit has been reached, a visual warning is
issued and a warning tone sounds.
Obser vethe no tes on driving sy stems and your
re sponsibility; you may otherwise failto recog‐
nise dangers (/ page 168).
Sy stem limits
Ac tive Steering Assist has a limited steering tor‐
qu efo r lateral guidance. In some cases, the
st eering inter vention is not su fficient tokeep the
ve hicle in the lane or todrive thro ugh exits.
The sy stem may be impaired or may not function
in thefo llowing ins tances:
R The reis poor visibilit y,e.g. due tosno w,rain,
fo g, heavy spr ay, greatly varying light condi‐
tions or strong shado wsonthe car riag ewa y.
R There is glare, e.g. from oncoming traf fic,
di re ct sunlight or reflections.
R Insuf ficient road illumination. R
The windsc reen is dirty, mis ted up, damaged
or co vered in the vicinity of the camera, e.g.
by ast icke r.
R No, or se veral, unclear lane markings are
present for one lane, or the markings change
qu ickl y,forex ample, in a con stru ction area
or junctions.
R The lane markings are wornaw ay, dark or
co vered up, e.g. bydirt or sno w.
R Ifth e dis tance totheve hicle in front is too
short and thus the lane markings cann otbe
de tected.
R The road is nar rowand winding.
R There are obs tacles on the lane or projecting
out into the lane, such as object mar kers.
The sy stem does not pr ovide assis tance in the
fo llowing conditions:
R On tight bends and when turning.
R When crossing junctions.
R Atroundabouts or tollst ations.
R When towing a trailer.
R When the tyre pressure is too lo w. &
WARNING Risk of accident if Active
St eering Assist unexpectedly stops func‐
tioning
If th e sy stem limits of Active Steering Assist
are reached there is no guarantee that the
sy stem will remain active or will keep the
ve hicle in lane. #
Alw ayske ep your hands on thesteering
wheel and obser vethe tra ffic carefull y. #
Alw aysst eer theve hicle paying atten‐
tion totraf fic conditions. &
WARNING Risk of accident if Active
St eering Assist unexpectedly inter venes
The de tection of lane markings and objects
may malfunction and cause unexpected
st eering inter ventions. #
Steer according totraf fic conditions. Ac
tivating Active Steering Assist
Re quirements:
R ESP ®
must be activated, but not inter vening. Driving and pa
rking 187

R
Active Dis tance Assi stDISTRONIC is acti va‐
te d. #
If indicator lamp 1is off: press button 2. Fu
nction of Active Eme rgency Stop Assist If
th e sy stem de tects that the driver has not
st eered theve hicle for a considerable period of
time or has remo vedth eir hands from thesteer‐
ing wheel, display 1appears in the multifunc‐
tion displa y.Ifth e driver still does not steer the
ve hicle, or gives no confirmation tothe sy stem,
a wa rning tone sounds in addition tothe visual
wa rning message.
If th e driver still does not respond tothewa rn‐
ing, theBeginning emergency stop message
appears in the multifunction displa y.Ifth e driver
st ill does not respond, Active Dis tance Assi st DISTRONIC
reduces the speed. The vehicle is
decelerated in stages toast andstill.
Depending on the count ry, at speeds below
60 km/h the hazard warning lights switch on
automaticall y.
When theve hicle is stationar y,thefo llowing
actions are car ried out:
R The vehicle is secured with the electric park‐
ing brake.
R Active Dis tance Assi stDISTRONIC is ended
R The vehicle is unloc ked.
R If possible, an emer gency call is placed to
th e Mercedes-Benz emer gency call centre
The driver can cancel the deceleration at any
time byper form ing one of thefo llowing actions:
R Steering
R Braking or accelerating
R Deactivating Active Dis tance Assi st
DISTRONIC 18 8
Driving and pa rking

Ac
tive Brake Assi st Fu
nction of Active Brake Assi st
Ac tive Brake Assi stconsi sts of thefo llowing
functions:
R Distance warning function
R Autonomous braking function
R Situation-dependent braking assi stance
R Vehicles with Driving Assistance Pack‐
age: Evasi veSteering Assist and cornering
function
Ac tive Brake Assi stcan help youto minimise the
ri sk of a collision with vehicles, cyclists or
pedestrians or toreduce the ef fects of su ch a
collision.
If Ac tive Brake Assi sthas de tected a risk of colli‐
sion, a warning tone sounds and theL dis‐
ta nce warning lamp lights up in the instrument
clus ter.
If yo u do not react tothewa rning, autonomous
braking can be initiated in critical situations.
In especially critical situations, Active Brake
Assi stcan initia teautonomous braking direct ly.In
this case, thewa rning lamp and warning tone
occur simultaneously wi th the braking applica‐
tion.
If yo u apply the brake yourself in a critical situa‐
tion or apply the brake during autonomous brak‐
ing, situation-dependent braking assis tance
occu rs. The brake pressure increases up tomax‐
imum full-s top braking if necessar y.
Obser vethe no tes on driving sy stems and your
re sponsibility; you may otherwise failto recog‐
nise dangers (/ page 168). If autonomous braking or si
tuation-dependent
braking assi stance has occur red, display 1 appears in
the multifunction display and then
automatically goes out af ter a short time. &
WARNING Risk of accident due tolimi‐
te d de tection per form ance of Active
Brake Assi st
Ac tive Brake Assi stcannot al ways clear ly
identify objects and complex traf fic situa‐
tions.
Ac tive Brake Assi stis only an aid. The driver
is responsible for maintaining a suf ficiently
safe di stance totheve hicle in front, vehicle
speed and for braking in good time. #
Alw ays pay careful attention tothe traf‐
fi c situation; do not rely on Active Brake
Assi stalone. #
Be prepared tobrake or swer veif nec‐
essar y. Also obser
vethe sy stem limits of Active Brake
Assi st. Driving and pa
rking 18 9

The individual subfunctions are
available in
va rious speed ranges:
The dis tance warning function can issue a warn‐
ing in thefo llowing situations:
R From appr oximately 30 km/h, if over se veral
seconds the dis tance maintained totheve hi‐
cle tr avelling in front is insuf ficient forthe
driven speed, theL distance warning
lamp lights up in the instrument clus ter.
R From appr oximately 7 km/h, if your vehicle
is critically close toave hicle, cyclist or
pedestrian, you will hear an intermit tent
wa rning tone and theL distance warning
lamp lights up in the instrument clus ter.
Brake immediately or take evasive action, pr ovi‐
ded it is safe todo so and the traf fic situation
allo wsthis. Distance
warning function (vehicles without
Driving Assistance Package)
The dis tance warning function can aid you in the
fo llowing situations with an intermit tent wa rning
to ne and a warning lamp:
R at speeds up toappr oximately 250 km/h
when approaching vehicles ahead
R at speeds up toappr oximately 80 km/h
when approaching stationary vehicles or
moving pedestrians and cyclists ahead
R at speeds up toappr oximately 60 km/h
when approaching crossing cyclists
Distance warning function (vehicles with
Driving Assistance Package)
The dis tance warning function can aid you in the
fo llowing situations with an intermit tent wa rning
to ne and a warning lamp:
R at speeds up toappr oximately 250 km/h
when approaching vehicles ahead
R at speeds up toappr oximately 100 km/h
when app roaching stationary vehicles R
at speeds up toappr oximately 80 km/h
when approaching moving pedestrians and
cyclists ahead
R at speeds up toappr oximately 70 km/h
when approaching stationary pedestrians,
crossing vehicles and stationary and crossing
cyclists
Au tonomous braking function (vehicles with‐
out Driving Assistance Package)
If th eve hicle is tr avelling at speeds abo ve
appr oximately 7 km/h, the autonomous braking
function may inter vene in thefo llowing situa‐
tions:
R at speeds up toappr oximately 200 km/h
when approaching vehicles ahead
R at speeds up toappr oximately 80 km/h
when approaching cyclists ahead
R at speeds up toappr oximately 60 km/h
when approaching moving pedestrians and
crossing cyclists
R at speeds up toappr oximately 50 km/h
when approaching stationary vehicles 19 0
Driving and pa rking