trailer MERCEDES-BENZ C-CLASS COUPE 2021 Service Manual

Lights
Display messages
Possible causes/consequences and M
MSolutions
: Left dipped beam (examp le) *T
he cor responding light source is defective. #
Drive on carefully. #
Consult a qualified specialist workshop immediatel y.
% LED light sources: the display message forth e cor responding light appears only when allthe light-emitting
diodes in the light are faulty.
: Malfunction See Owner's
Manual *T
heexterior lighting is malfunctioning. #
Consult a qualified specialist workshop.
* Ve hicles with a trailer hitch: a fuse may haveblown. #
Stop theve hicle in accordance with the tra ffic conditions. #
Check the fuses and replace them if necessary (/ page 395).
:
Automatic driving lights
inoperative *T
he light sensor for auto matic driving lights is malfunctioning. #
Consult a qualified specialist workshop. Display messages and
warning/indicator lamps 439

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
If th e display message does not disappear: #
Stop theve hicle in accordance with the tra ffic conditions. #
Clean the windscreen.
Blind Spot Assist currently
unavailable See Owner's
Manual *B
lind Spot Assist is temp orarily una vailable.
The sy stem limits ha vebeen reached (/ page 202).
Once the cause of the problem is no longer present, the sy stem will be available again. #
Drive on.
or #
Ifth e display message does not disappear, stop theve hicle in accordance with the tra ffic conditions and restart
th e engine. #
If necessar y,clean there ar bumper. If the bumper is especially dirty, the sensors in the bumper may be mal‐
functioning.
Blind Spot Assist inopera-
tive *B
lind Spot Assist is malfunctioning. #
Consult a qualified specialist workshop.
Blind Spot Assist not availa-
ble when towing a trailer
See Owner's Manual *W
hen you es tablish the electrical connection tothe trailer, Blind Spot Assist will be una vailable. #
Press the left-hand Touch Control and ackn owledge the display message. Display messages and
warning/indicator lamps 463

Display messages
Possible causes/consequences and M
MSolutions
Active Blind Spot Assist
currently unavailable See
Owner's Manual *A
ctive Blind Spot Assi stistemp orarily una vailable.
The sy stem limits ha vebeen reached (/ page 202).
Once the cause of the problem is no longer present, the sy stem will be available again. #
Drive on.
or #
Ifth e display message does not disappear, stop theve hicle in accordance with the tra ffic conditions and restart
th e engine.
Active Blind Spot Assist
inoperative *A
ctive Blind Spot Assi stis malfunctioning. #
Consult a qualified specialist workshop.
Active Blind Spot Assist
not available when towing
a trailer See Owner's Man-
ual *W
hen you es tablish the electrical connection tothe trailer, Active Blind Spot Assi stwill be una vailable. #
Press the left-hand Touch Control and ackn owledge the display message.
Active Lane Keeping Assist
currently unavailable See
Owner's Manual *A
ctive Lane Keeping Assist is temp orarily una vailable.
The ambient conditions are outside the sy stem limits (/ page 205).
As soon as the ambient conditions are within the sy stem limits, the sy stem will become available again.
Ve hicles with Active Steering Assis t:the camera view may be limited bythe windscreen. #
Drive on. 464
Display messages and warning/indicator lamps

Display messages
Possible causes/consequences and M
MSolutions
É Vehicle rising Please wait *T
hevehicle le vel is too lo w.The vehicle will be raised tothe selected vehicle le vel. #
Wait until the display message disappears before pulling away.
É Please reduce speed *Y
ou are driving toofast forth e selected vehicle le vel. #
Toadjust theve hicle le vel,yo u must not drive at speeds greaterth an 60 km/h. #
Toadjust theve hicle le vel during trailer operation, you must not drive at speeds greaterth an 30 km/h.
Parking Assist Manoeu-
vring assistance limited
See Owner's Manual *T
heParking Assist manoeuvring assis tant is temp orarily una vailable or only partially available. #
Clean all sensors of the parking and camera sy stem (/ page373). #
Ifth e display message still appears, consult a qualified specialist workshop.
Parking Assist and
PARKTRONIC inoperative
See Owner's Manual *
Ve hicles with Active Parking Assis t:Ac tive Parking Assist and Parking Assist PARKTRONIC are malfunctioning.
Ve hicles without Active Parking Assis t:Pa rking Assist PARKTRONIC is malfunctioning. #
Stop theve hicle in accordance with the tra ffic conditions and restart the engine. #
Ifth e display message still appears, consult a qualified specialist workshop. 468
Display messages and warning/indicator lamps

Instrument display (standard)
Wi
descreen co ckpit instrument displ ay Depending on
the display setting, the positions
of the indicator lamps on the instrument display
may dif fer from theex ample shown.
Indicator and warning lamps:
6 Re
stra int sy stem (/ page 489)
ü Seat belt (/
page 489)
ï Trailer hit ch (/page 490)
Ù Powe rst eering (/ page 490)
ÿ Coolanttemp erature (/ page 491)
; Engine diagnostics (/
page 491)
% Ve
hicles with a diesel engine: pre‐
gl ow
# Electrical
fault (/ page 491)
8 Re
ser vefuel with fuel filler flap loca‐
tion indicator (/ page 491)
! Elect
ric pa rking brake (red)
(/ page 494)
! Electric parking brake (yellow)
(/
page 494)
J Brakes (yellow) (/
page 494)
J Brakes (red) (/
page 494) L
Distance warning (/ page 496)
ä AIRMATIC (/ page 496)
ä DYNA MIC BODY CONTROL
(/ page 496)
! ABS (/
page 497)
÷ ESP®
(/ page 497)
å ESP®
OFF (/ page 497)
h Ty
re pressure monitoring sy stem
(/ page 500)
T St
anding lights (/ page121)
L Low beam (/
page121)
K High beam (/
page123)
#! Tu
rn signal lights (/ page123)
R Re
ar fog light (/ page121) 488
Displaymessa ges and warning/indicator lamps

Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions
ï Tr ailer tow hit chwarning
lamp *T
hered trailer hitch warning lamp is lit.
The trailer hitch is not operational. &
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. #
Notethe messages on the multifunction displa y.Engine
Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions
ÿ Coolant warning lamp *T
he red coolant warning lamp is lit while the engine is running.
Po ssible causes:
R The temp erature sensor is malfunctioning
R The coolant le vel is too low
R The air supply tothera diator is obstructed
R The radiator fan is faulty Display messages and
warning/indicator lamps 491

DIRECT SELECT le
ver
Engaging drive position........................ .159
Engaging neutral................................... .158
Engaging park position.......................... 15 9
Engaging pa rkposition automatically....1 59
Engaging reve rsege ar........................... 15 8
Fu nction................................................ 157
Display (care) ............................................ .374
Display (multimedia sy stem)
Settings................................................. 263
Display (on-boa rdcompu ter)
Displ ays on the multifunction displa y.... 236
Displ aymessage
Calling up (on-board compu ter)............. 433
No tes....................................................4 33
Display messages ¯ - - - km/h ..................................... 458
ç - - - km/h ..................................... 459
È - - - km/h ..................................... 459
# 12V battery See Owner's Man‐
ual..........................................................4 74Û
48 V battery See Owner's Man‐
ual.......................................................... 476
: Active Light Sy stem inoperative... 440
¯ AdBlue sy stem fault Emer. op.:
max. XXX mphSt art not poss. in XXX
miles .................................................... .484
¯ AdBlue sy stem fault Emer‐
ge ncy op. in XXX km See Owner's
Manual.................................................. 483
¯ AdBlue sy stem fault Engine
st art not possible................................. .484
¯ AdBlue sy stem fault See Own‐
er's Manual .......................................... .483
5 Add 1 litre engine oil when
next refuelling....................................... 485
é ATTENTION ASSIST inoperative ....458
é ATTENTION ASSIS T:Take a
break!....................................................4 58
: Automatic driving lights inoper‐
ative...................................................... 439 Á
Change key bat teries .................... 437
J Check brake fluid le vel................. 456
# Check brake pads See Owner's
Manual.................................................. 457
5 Check engine oil le vel when
next refuelling....................................... 485
ï Checktrailer hitch lo ck................ 443
h Check tyre(s) ................................ 478
! Clean the fuel filter ...................... 449
ÿ Coolant Stop vehicle Switch
engine off..............................................4 48
! currently una vailable See Own‐
er's Manual .......................................... .469
÷ currently una vailable See Own‐
er's Manual .......................................... .470
5 Engine oil le vel cannot be
measured .............................................. 487
5 Engine oil le velRe duce oil le vel.... 486
5 Engine oil le velSt op vehicle
Switch engine off.................................. 486 Index
511

:
Switch on headlamps................... 440
Ø Top up AdBlue Emergency op.
in XXX miles See Owner's Manual......... 482
+ Top up coolant See Owner ’s
Manual.................................................. 448
¥ Top up washer fluid ...................... 447
! Turn on the ignition torelease
th e parking brake..................................4 56
d Vehicle is operational Switch
off ignition before exiting..................... .443
É Vehicle rising Please wait............ .468
É Vehicle rising................................4 67
h Warning tyre defect..................... .479
h Wheel sensor(s) missing............... 478
Ø XX,X l Top up AdBlue Switch on
ignition, wait 60 sec. or eng. start
not poss................................................ 483
Ac tive Blind Spot Assi stcur rently
una vailable See Owner's Manual ...........464
Ac tive Blind Spot Assi stinope rative ...... 464 Ac
tive Blind Spot Assi stnot available
when towing a trailer See Owner's
Manual .................................................. 464
Ac tive bonnet malfunction See Own‐
er's Manual........................................... 445
Ac tive Brake Assi stFunctions cur‐
re ntly limited See Owner's Manual ........472
Ac tive Brake Assi stFunctions limited
See Owner's Manual.............................. 473
Ac tive Dis tance Assi stavailable again ...4 60
Ac tive Dis tance Assi stcur rently
una vailable See Owner's Manual ...........460
Ac tive Dis tance Assi stinope rative ........ 460
Ac tive Lane Keeping Assist Camera
view restricted See Owner's Manual..... 465
Ac tive Lane Keeping Assist cur rently
una vailable See Owner's Manual ...........464
Ac tive Lane Keeping Assist inopera‐
tive........................................................ 465 Ac
tive Steering Assist cur rently
una vailable due tomultiple emer‐
ge ncy stops...........................................4 61
Ac tive Steering Assist cur rently
una vailable See Owner's Manual ...........461
Ac tive Steering Assist inoperative ..........461
Ad aptive Highbeam Assist Plus Cam‐
era view restricted See Owner's
Manual................................................... 441
Ad aptive Highbeam Assist Plus cur‐
re ntly una vailable See Owner's Man‐
ual......................................................... 441
Ad aptive Highbeam Assist Plus inop‐
erative.................................................. .441
App lybrake todeselect Park (P)
position................................................. 450
Apply brake toselect R......................... 450
Au xilia rybattery malfunction (red
display message) ...................................4 52 Index
513