2018 MERCEDES-BENZ CLS ECU

Display messages
Possible causes/consequences and P Solutions
PRE-SAFE
Functions Currently
Limite d See Opera‐
tor's Manual PRE ‑ S AF E ®
PLU S or PRE ‑ SAFE ®
Brake is temporarily inoperative.
Possibl e causes are: R
function is impaire d due to heav y rain or snowR
th e radar sensor system is temporarily inoperative, e.g. due to elec -
tromagneti c radiation emitted by nearby TV or radi o station s or
other source s of electromagneti c radiationR
Mercedes-AMG vehicles: ES P ®
is deactivatedR
th e system is outside th e operating temperature rangeR
th e on-boar d voltag e is to o low.
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
PRE ‑ S AF E ®
PLU S and PRE ‑ S AF E ®
Brake are operational again .
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 141).X
Restart th e engine.X
Mercedes-AMG vehicles: switch ES P ®
on again ( Y
page 71).
PRE-SAFE
Functions Limite d
See Operator' s Man ‐
ual PRE ‑ S AF E ®
PLU S or PRE ‑ SAFE ®
Brake is unavailable due to a mal-
function . BA S PLU S wit h Cross-Traffic Assis t may also hav e failed.X
Visit a qualified specialist workshop .Display messages 20 7
On-board computer and displays Z

Display messages
Possible causes/consequences and P Solutions
Radar Sensor s Dirty
See Operator' s Man ‐
ual The radar sensor system is malfunctioning .
Possibl e causes are: R
Dirt on sensor sR
Heavy rain or snow R
Whe n drivin g on inter-urban roads without traffic or infrastructure,
e.g. in desert-like area s
At least on e drivin g system or drivin g safet y system is malfunctioning
or is temporarily unavailable :R
COLLISION PREVENTION ASSIST PLU SR
PRE-SAF E ®
BrakeR
PRE-SAF E ®
PLU SR
Active Lan e Keepin g Assis tR
Active Blind Spot Assis tR
DISTRONI C PLU S wit h Steering Assis t and Stop&Go Pilo t
If th e radar sensor system in fron t is dirty, Active Blind Spot Assis t will
no t perfor m a course-correcting brak e application .
A warning tone also sounds.
Once th e caus e of th e problem is no longer present, th e drivin g and
drive safet y systems will be available again . The display message dis-
appears.
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 141).X
Switc h off th e engine.X
Clean all sensor s ( Y
page 274).X
Restart th e engine.
The display message disappears.
u SRS Malfunction Ser ‐
vic e Required The restrain t system is malfunctioning . The u warning lamp also
lights up in th e instrumen t cluster.
G WARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th e event of an accident, may no t be triggered .
There is an increased ris k of injury.X
Visit a qualified specialist workshop immediately.
Observ e th e additional information on restrain t systems ( Y
page 41).208
Display messages
On-board computer and displays

Display messages
Possible causes/consequences and P Solutions
Front Passenger Air ‐
bag Disabled
See Operator' s Man ‐
ual The front-passenger fron t air bag and front-passenger knee bag are
deactivated during th e journey, although:R
an adult
or R
a person of th e correspondin g statur e is on th e front-passenger seat
If additional force s are applie d to th e seat , th e system may interpret
th e occupant's weigh t as lower than it actually is.
G WARNIN G
The front-passenger fron t air bag and front-passenger knee bag does
no t deploy in th e event of an accident.
There is an increased ris k of injury.X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 141).X
Switc h th e ignition off .X
Hav e th e occupant get out of th e vehicle.X
Kee p th e seat unoccupied , close th e front-passenger door and
switch on th e ignition .X
Observ e th e PASSENGER AI R BA G OF F indicator lamp in th e center
console and th e multifunction display and chec k th e following:
Seat unoccupied and ignition switched on :R
a self-diagnosis is carrie d out . The PASSENGER AI R BA G OF F and
PASSENGER AI R BA G ON indicator lamp s mus t ligh t up simulta-
neousl y for approximately six seconds R
th e PASSENGER AI R BA G O F F indicator lamp mus t then ligh t up
and remain lit after th e self-diagnosis . If th e indicator lamp is on ,
th e OCS (Occupant Classification System) has disabled th e front-
passenger fron t air bag and front-passenger knee bag
( Y
page 49) R
th e Front Passenger Airbag Enable d See Operator' s
Manual or Front Passenger Airbag Disabled See Opera‐
tor's Manual display message s mus t no t be shown in th e mul-
tifunction display X
Wait for a period of at least 60 seconds until th e necessar y system
checks hav e been completed.X
Mak e sur e that th e display message s do no t appear in th e multi-
function display.
If these condition s are fulfilled , th e front-passenger seat can be occu-
pied again . Whether th e PASSENGER AI R BA G OF F indicator lamp
remain s lit or goe s out depend s on how OCS classifies th e occupant .
If th e condition s are no t fulfilled , th e system is no t operating correctly.X
Visit a qualified specialist workshop immediately.
Observ e th e additional information on OCS ( Y
page 49).
Front Passenger Air ‐
bag Enable d The front-passenger fron t air bag and front-passenger knee bag are
enabled during th e journey, although:210
Display messages
On-board computer and displays

Display messages
Possible causes/consequences and P Solutions
See Operator' s Man ‐
ual R
a child, a small adult or an objec t weighing less than th e system' s
weigh t threshold is locate d on th e front-passenger seat
or R
th e front-passenger seat is unoccupied
The system may detec t objects or force s applyin g additional weigh t on
th e seat .
G WARNIN G
The front-passenger fron t air bag and front-passenger knee bag may
deploy unintentionally.
There is an increased ris k of injury.X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 141).X
Switc h th e ignition off .X
Ope n th e front-passenger door .X
Remove th e child and th e child restrain t system from th e front-
passenger seat .X
Mak e sur e that there are no objects on th e seat addin g to th e
weight.
The system may otherwise detec t th e additional weigh t and inter-
pre t th e seat occupant's weigh t as greate r than it actually is.X
Kee p th e seat unoccupied , close th e front-passenger door and
switch on th e ignition .X
Observ e th e PASSENGER AI R BA G OF F indicator lamp in th e center
console and th e multifunction display and chec k th e following:
Seat unoccupied and ignition switched on :R
a self-diagnosis is carrie d out . The PASSENGER AI R BA G OF F and
PASSENGER AI R BA G ON indicator lamp s mus t ligh t up simultane -
ousl y for approximately six seconds R
th e PASSENGER AI R BA G OF F indicator lamp mus t then ligh t up and
remain lit after th e self-diagnosis . If th e indicator lamp is on , th e
OCS has disabled th e front-passenger fron t air bag and front-
passenger knee bag ( Y
page 49 )R
th e Front Passenger Airbag Enable d See Operator' s Man ‐
ual or Front Passenger Airbag Disabled See Operator' s
Manual display message s mus t no t be shown in th e multifunction
display X
Wait for a period of at least 60 seconds until th e necessar y system
checks hav e been completed.X
Mak e sur e that th e display message s do no t appear in th e multi-
function display.
If these condition s are fulfilled , th e front-passenger seat can be occu-
pied again . Whether th e PASSENGER AI R BA G OF F indicator lamp
remain s lit or goe s out depend s on how OCS classifies th e occupant .
If th e condition s are no t fulfilled , th e system is no t operating correctly.X
Visit a qualified specialist workshop immediately.
Observ e th e additional information on OCS ( Y
page 49).Display messages 21 1
On-board computer and displays Z

Display messages
Possible causes/consequences and P Solutions
= See Operator' s Man ‐
ual The battery is no t bein g charged.
A warning tone also sounds.
Possibl e causes are: R
a defective alternato rR
a torn poly-V-belt R
a malfunction in th e electronics
! Do no t continu e driving. The engin e could otherwise overheat.X
Pull ove r and stop th e vehicl e safely and switch off th e engine, pay-
ing attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 141).X
Consult a qualified specialist workshop .
= Sto p Vehicl e See
Operator' s Manual The battery is no longer bein g charged and th e battery charg e level is
to o low.
A warning tone also sounds. X
Pull ove r and stop th e vehicl e safely and switch off th e engine, pay-
ing attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 141).X
Observ e th e instruction s in th e = See Operator' s Manual
display message .X
Consult a qualified specialist workshop .

Display messages
Possible causes/consequences and P Solutions
Lan e Keepin g Assist
Currently Unavaila‐
ble See Operator' s
Manual or Active
Lan e Keepin g Assist
Currently Unavaila‐
ble See Operator' s
Manual Lan e Keepin g Assis t or Active Lan e Keepin g Assis t is deactivated and
temporarily inoperative.
Possibl e causes are: R
th e windshield in th e camera' s field of vision is dirtyR
visibilit y is impaire d due to heav y rain , snow or fogR
there hav e been no lan e marking s for an extended periodR
th e lan e marking s are worn, dark or covered, e.g. by dir t or snow
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
Lan e Keepin g Assis t or Active Lan e Keepin g Assis t is operational
again .
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 141).X
Clean th e windshield.
Lan e Keepin g Assist
Inoperative or
Active Lan e Keepin g
Assist Inoperative Lan e Keepin g Assis t or Active Lan e Keepin g Assis t is malfunctioning .X
Visit a qualified specialist workshop .
Blind Spo t Assist
Currently Unavaila‐
ble See Operator' s
Manual or Active
Blind Spo t Assist
Currently Unavaila‐
ble See Operator' s
Manual Blind Spot Assis t or Active Blind Spot Assis t is temporarily inoperative.
Possibl e causes are: R
th e radar sensor system is outside th e operating temperature rangeR
th e radar sensor system is temporarily inoperative, e.g. due to elec -
tromagneti c radiation emitted by nearby TV or radi o station s or
other source s of electromagneti c radiation
The yellow c indicator lamp s also ligh t up in th e exterio r mirrors.
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
Blind Spot Assis t or Active Blind Spot Assis t is operational again .
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 141).X
Restart th e engine.
Blind Spo t Assist
Inoperative or
Active Blind Spo t
Assist Inoperative Blind Spot Assis t or Active Blind Spot Assis t is malfunctioning .
The yellow c indicator lamp s also ligh t up in th e exterio r mirrors.X
Visit a qualified specialist workshop .
Par k Assist Canceled The driver's door is open and th e driver's seat belt has no t been fas -
tened. X
Repeat th e parking process wit h th e seat belt fastene d and th e
driver's door closed .Display messages 21 7
On-board computer and displays Z

Display messages
Possible causes/consequences and P Solutions
DISTRONIC PLU S Cur ‐
rently Unavailable
See Operator' s Man ‐
ual DISTRONI C PLU S is temporarily inoperative.
Steering Assis t and Stop&Go Pilo t are temporarily inoperative.
Possibl e causes are: R
th e radar sensor system is temporarily inoperative, e.g. due to elec -
tromagneti c radiation emitted by nearby TV or radi o station s or
other source s of electromagneti c radiationR
th e system is outside th e operating temperature rangeR
th e on-boar d voltag e is to o low.
A warning tone also sounds.
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
DISTRONI C PLU S is operational again .
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 141).X
Restart th e engine.
DISTRONIC PLU S Inop‐
erativ e DISTRONI C PLU S is malfunctioning
The followin g may hav e also failed:R
BA S PLU S wit h Cross-Traffic Assis tR
PRE-SAF E ®
BrakeR
Steering Assis t and Stop&Go Pilo t
A warning tone also sounds. X
Visit a qualified specialist workshop .
DISTRONIC PLU S Sus ‐
pended You hav e depressed th e accelerato r pedal . DISTRONI C PLU S is no
longer controllin g th e speed of th e vehicle.X
Remove your foo t from th e accelerato r pedal .
DISTRONIC PLU S
- - - mph An activation condition for DISTRONI C PLU S is no t fulfilled .X
Chec k th e activation condition s for DISTRONI C PLU S ( Y
page 149).Display messages 21 9
On-board computer and displays Z

Display messages
Possible causes/consequences and P Solutions
DTR+: Steering
Assist . Currently
Unavailable See
Operator' s Manual Steering Assis t and Stop&Go Pilo t are temporarily inoperative.
Possibl e causes are: R
th e windshield in th e camera' s field of vision is dirtyR
visibilit y is impaire d due to heav y rain , snow or fogR
there hav e been no lan e marking s for an extended periodR
th e lan e marking s are worn, dark or covered, e.g. by dir t or snow
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
Steering Assis t and Stop&Go Pilo t are operative again .
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 141).X
Clean th e windshield.
DTR+: Steering
Assist . Inoperative Steering Assis t and Stop&Go Pilo t are defective.
However, th e DISTRONI C PLU S function s are still available.
A warning tone also sounds. X
Visit a qualified specialist workshop .
Cruise Contro l Inop‐
erativ e Cruis e control is malfunctioning .
A warning tone also sounds. X
Visit a qualified specialist workshop .
Cruise Contro l
- - - mph A condition for activating cruise control has no t been fulfilled .
You hav e tried to store a speed belo w 20 mph (30 km/ h) , for example.X
If conditions permit, drive faster than 20 mph (30 km/ h) and store
the speed. X
Check the activation conditions for cruise control ( Y
page 148).
Cruise Control Off Cruise control has been deactivated.
If a warning tone also sounds, cruise control has deactivated auto-
matically ( Y
page 148).220
Display messages
On-board computer and displays