ECU MERCEDES-BENZ S CLASS 2017 Owner's Guide

Display messages
Possible causes/consequences and P Solutions
Collision Preven ‐
tio n Assist Plu s
Inoperative COLLISION PREVENTION ASSIST PLU S is temporarily inoperative due
to a malfunction . Adaptive Brake Assis t may also hav e failed.X
Visit a qualified specialist workshop immediately.
PRE-SAFE Inopera‐
tiv e See Operator' s
Manual Importan t function s of PRE-SAF E ®
hav e failed. Al l other occupant
safet y systems , e.g. air bags , remain available.X
Visit a qualified specialist workshop immediately.
PRE-SAFE Functions
Currently Limite d
See Operator' s Man ‐
ual 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
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 162).X
Restart th e engine.
PRE-SAFE Functions
Limite d See Opera‐
tor's Manual 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 immediately.234
Display messages
On-board computer and displays

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
PRE-SAF E ®
PLU SR
PRE-SAF E ®
BrakeR
COLLISION PREVENTION ASSIST 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 162).X
Switc h off th e engine.X
Clean all sensor s ( Y
page 323).X
Restart th e engine.
The display message disappears.
Check Lef t Rea r
Bel t See Operator' s
Manual or Check
Right Rea r Bel t See
Operator' s Manual The seat belt buckl e extender on th e right or lef t of th e rear compart-
men t is no t in th e predefine d position . The belt strap may be jammed
in th e belt tongue.
G WARNIN G
If th e seat belt buckl e extender is no t in th e predefine d position , th e
seat belt canno t provid e th e intended level of protection .
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
Releas e th e jamming.X
Repeat th e seat belt fastenin g procedure .Display messages 23 5
On-board computer and displays Z

Display messages
Possible causes/consequences and P Solutions
Front Passenger Air ‐
bag Disabled See
Operator' s Manual The front-passenger fron t air bag is deactivated during th e journey,
eve n though : 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 air bag does no t deploy during 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 162).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 indicator lamp s 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 OF F indicator lamp mus t then ligh t up
and remain lit after th e s elf-diagnosis . If th e indicator lamp is on ,
OCS has disabled th e front-passenger fron t air bag ( Y
page 51)R
th e display message s Front Passenger Airbag Enable d
See Operator' s Manual or Front Passenger Airbag Dis ‐
abled See Operator' s Manual mus t no t appear in th e multi-
function 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.
Fo r further information about th e Occupant Classification System, see
( Y
page 51).
Front Passenger Air ‐
bag Enable d See
Operator' s Manual The front-passenger fron t air bag is enabled during th e journey, eve n
though : 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 seatDisplay messages 23 9
On-board computer and displays Z

Display messages
Possible causes/consequences and P Solutions
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 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 162).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 indicator lamp s 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 ligh t up simultaneousl y
for approximately six seco ndsR
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 ,
OCS (Occupant Classification System) has disabled th e front-
passenger fron t air bag ( Y
page 51 )R
th e display message s Front Passenger Airbag Enable d
See Operator' s Manual or Front Passenger Airbag Dis ‐
abled See Operator' s Manual mus t no t appear in th e multi-
function 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.
Fo r further information about th e Occupant Classification System, see
( Y
page 51).240
Display messages
On-board computer and displays

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 162).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 condition of charg e 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 162).X
Observ e th e instruction s in th e = See Operator' s Manual
display message .X
Consult a qualified specialist workshop .
= Sto p Vehicl e Leave
Engine Runnin g The battery condition of charg e is to o low.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. Do no t continu e drivin g
under any circumstances. X
Leav e th e engin e running.X
Wait until th e display message disappear s before pullin g away.
= Start Engine See
Operator' s Manual The engin e is switched off and th e condition of charg e is to o low.X
Switc h off electrical consumer s that you do no t need, suc h as th e
rear window defroste r and interior lighting .X
Leav e th e engin e runnin g for a few minute s or drive a lon g distance.
The battery is bein g charged.Display messages 24 3
On-board computer and displays Z

Display messages
Possible causes/consequences and P Solutions
ABC Malfunction
Sto p Vehicl e The Active Body Control (ABC) vehicl e level is to o low.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.
Afte r a few seconds, th e vehicl e level is adjusted and th e display
message disappears.
The multifunction display continuousl y shows th e display message .
The vehicl e is leaking oil. 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. Do no t continu e drivin g
under any circumstances. X
Consult a qualified specialist workshop .
The multifunction display continuousl y shows th e display message .
Active Body Control (ABC) is malfunctioning .X
Do no t drive at speeds abov e 50 mph (80 km/h).X
Mak e only slight steering movements. Otherwise , th e fron t fender
or th e tires could be damaged if th e steering movement is to o large.X
Liste n for scraping sounds. X
Visit a qualified specialist workshop .
ABC Vehicl e Rising
Please Wai t Briefl y The vehicl e level is to o low when th e vehicl e is stationary. A warning
tone also sounds. X
Do no t pull away.
The vehicl e level is set when th e display message disappears.
ABC Malfunction The Active Body Control (ABC) function is restricted. The vehicle's
handlin g characteristics may be affected. X
Do no t drive at speeds abov e 50 mph (80 km/h).X
Visit a qualified specialist workshop .
Active Lan e Keepin g
Assist Currently
Unavailable See
Operator' s Manual 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.
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 162).X
Clean th e windshield.246
Display messages
On-board computer and displays

Display messages
Possible causes/consequences and P Solutions
Active Lan e Keepin g
Assist Inoperative Active Lan e Keepin g Assis t is malfunctioning .X
Visit a qualified specialist workshop .
Active Blind Spo t
Assist Currently
Unavailable See
Operator' s Manual 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
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
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 162).X
Restart th e engine.
Active Blind Spo t
Assist Inoperative Active Blind Spot Assis t is malfunctioning .X
Visit a qualified specialist workshop .
Par k Assist Canceled The driver's door is open .X
Repeat th e parking gap measuremen t and parking process wit h th e
driver's door closed .
You touched th e multifunction steering whee l while steering inter-
vention was active .X
Whil e steering intervention is active , mak e sur e that th e multifunc-
tion steering whee l is no t touched unintentionally.
The vehicl e has started to skid and ES P ®
has intervened.X
Use Active Parking Assis t again later ( Y
page 186).
Par k Assist Inoper ‐
ative PARKTRONI C is malfunctioning or faulty.X
Follow th e instruction s and helpful hints in th e "Problem s wit h
PARKTRONIC" section ( Y
page 186).
If th e multifunction display still shows th e display message :X
Visit a qualified specialist workshop .
Active Parking Assis t is unavailable or faulty.X
Switc h off th e ignition and restar t th e engine.
If Active Parking Assis t continues to be unavailable (the ] symbol is
no t shown in th e multifunction display):X
Visit a qualified specialist workshop .Display messages 24 7
On-board computer and displays Z

Display messages
Possible causes/consequences and P Solutions
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 171).
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 162).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 .250
Display messages
On-board computer and displays

Tires Display messages
Possible causes/consequences and P Solutions
Check Tire Pressure
Soon Canada only:
The tire pressure loss warning system has detected a significant loss
in pressure.
A warning tone also sounds.
Possible causes: R
you have changed the positions of the wheels and tires or installed
new wheels and tires. R
the tire pressure in one or more tires has dropped
G WARNING
Tire pressures that are too low pose the following hazards: R
they may burst, especially as the load and vehicle speed increase. R
they may wear excessively and/or unevenly, which may greatly
impair tire traction. R
the driving characteristics, as well as steering and braking, may be
greatly impaired.
There is a risk of an accident. X
Stop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so. X
Secure the vehicle against rolling away ( Y
page 162).X
Check the tires and, if necessary, follow the instructions for a flat
tire ( Y
page 327). X
Check the tire pressures and, if necessary, correct the tire pressure. X
Restart the tire pressure loss warning system when the tire pres-
sure is correct ( Y
page 352).
Check Tire Pressure
Then Restart Run
Flat Indicator Canada only:
The tire pressure loss warning system generated a display message
and has not been restarted since. X
Set the correct tire pressure in all four tires. X
Restart the tire pressure loss warning system ( Y
page 352).
Run Flat Indicator
Inoperative Canada only:
The tire pressure loss warning system is faulty. X
Visit a qualified specialist workshop.
Please Correct Tire
Pressure The tire pressure is too low in at least one of the tires, or the tire
pressure difference between the wheels is too great. X
Check the tire pressures at the next opportunity ( Y
page 349).X
If necessary, correct the tire pressure. X
Restart the tire pressure monitor ( Y
page 351).252
Displa y messages
On-board computer and displays

Display messages
Possible causes/consequences and P Solutions
Check Tires The tire pressur e in on e or mor e tires has dropped significantly. The
whee l position is shown in th e multifunction display.
A warning tone also sounds.
G WARNIN G
Tir e pressures that are to o low pos e th e followin g hazards :R
they may burst, especially as th e load and vehicl e speed increase.R
they may wear excessivel y and/o r unevenly, whic h may greatl y
impair tire traction .R
th e drivin g characteristics , as well as steering and braking , may be
greatl y impaired.
There is a ris k of an accident.X
Stop th e vehicl e without making any sudden steering or braking
maneuvers . Pay attention to th e traffic condition s as you do so.X
Secur e th e vehicl e against rollin g away ( Y
page 162).X
Chec k th e tires and , if necessary, follow th e instruction s for a flat
tire ( Y
page 327). X
Chec k th e tire pressur e ( Y
page 349).X
If necessary, correc t th e tire pressure.
Warnin g Tir e Mal ‐
function The tire pressur e in on e or mor e tires has dropped suddenly. The whee l
position is shown in th e multifunction display.
G WARNIN G
Drivin g wit h a flat tire poses a ris k of th e followin g hazards :R
a flat tire affects th e abilit y to steer or brak e th e vehicle.R
you could lose control of th e vehicle.R
continued drivin g wit h a flat tire will caus e excessive heat build-up
and possibl y a fire.
There is a ris k of an accident.X
Stop th e vehicl e without making any sudden steering or braking
maneuvers . Pay attention to th e traffic condition s as you do so.X
Secur e th e vehicl e against rollin g away ( Y
page 162).X
Chec k th e tires and , if necessary, follow th e instruction s for a flat
tire ( Y
page 327).
Tir e Press. Monito r
Currently Unavaila‐
ble Becaus e there is interferenc e from a stron g source of radi o waves, no
signals from th e tire pressur e sensor s are detected. The tire pressur e
monitor is temporarily malfunctioning .X
Drive on .
The tire pressur e monitor restarts automatically as soo n as th e
problem has been resolved.
TirePress . Sen ‐
sor(s) Missin g There is no signal from th e tire pressur e sensor of on e or several
wheels. The pressur e of th e affecte d tire is no t displayed in th e mul-
tifunction display. X
Hav e th e fault y tire pressur e sensor replace d at a qualified special -
ist workshop . Display messages 25 3
On-board computer and displays Z