ECU MERCEDES-BENZ CLS COUPE 2012 Owner's Guide

Display messages Possible causes/consequences and
M Solutions
?
Coolan
tStopv ehi‐ cle Switch engine
off The coolan
tistoo hot.
Aw arning tone also sounds.
G WARNING
Never driv ewithano verheate dengine. Drivin gwhen your engine
is overheate dcan caus esom efluids which may have leaked into
the engine compartmen ttocatch fire.
Steam fro manoverheated engine can caus eserious burns, which
can occur just by opening the bonnet.
This pose sarisk of injury.
X Stop the vehicl eimmediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicl eagainst rolling away (Y page159).
X Leave the vehicl eand keep asafe distance from the vehicl euntil
the engine has coole ddown.
X Make sure that the air supply to the engine radiator is not
blocked ,e.g. by frozen slush.
X Do not start the engine again until the display message goes out
and the coolant temperature is under 120 †. The engine may
otherwise be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visi taqualified specialist
workshop immediately.
The reading may rise up to 120 †undernormal driving conditions
if the coolant has been filled correctly. Display messages
241On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
# The battery is no
tbeing charged.
Aw arning tone also sounds.
Possible causes:
R fault yalternator
R torn poly-V-belt
R am alfunctio nintheelectronics
X Stop th evehicle immediately, payin gattentio ntoroad and traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 159).
X Open the bonnet.
X Check whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
X Consult aqualified specialist workshop.
If the poly-V-belt is OK:
X Visit aqualified specialist workshop. 4
Check eng. oil
lev. when next
refuelling The engine oil level has dropped to the minimum level.
Aw
arning tone also sounds.
X Chec kthe oil level when next refuelling, at the latest
(Y page 298).
X If necessary, top up the engine oil (Y page 298).
X Have the engine checked at aqualified specialist workshop if
the engine oil needs topping up more often than usual. 4
Add
1 litre engine
oil when next refu‐
elling AMG vehicles: the engine oil level is too low.
X
Check the oil level when next refuelling, at the latest
(Y page 298).
X If necessary, top up the engine oil (Y page 298).
X Have the engine checked at aqualified specialist workshop if
the engine oil needs topping up more often than usual. 8
Reserve fuel level The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated when the fuel level
drops into the reserve range.
X
Refuel at the nearest filling station. 242
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
¨
STO
Pv ehicl eVehi‐ cle too low You hav
epulle daway while th evehicl elevel is still to olow.
AIRMATIC set sthe vehicl etotheselected level after ashort
period.
X Pull ove rand stop the vehicl esafelyass oonasp ossible,p aying
attention to road and traffic conditions.
X Secure the vehicle against rolling away( Ypage 159).
X Wait until the displaym essage disappears before pulling away. AIRMATIC is faulty.
Awarning tone also sounds.
X Do no tdriveats peeds abov e80km/h.
X Mak eonlys ligh tsteering movements. Otherwise, the front
wings or the tyres could be damage difthe steering movement
is too large.
X Liste nfor scraping sounds.
X Pull over and stop the vehicle safely, paying attention to road
and traffic conditions, and select ahigher vehicle level.
Depending on the malfunction, it may be possible to raise the
vehicle.
X Visit aqualified specialist workshop. ¨
Malfunction The AIRMATI
Cfunction is restricted. The vehicle's handling char-
acteristics may be affected.
X Do not drive at speeds above 80 km/h.
X Visit aqualified specialist workshop. Speed Limit Assist
currently unavail‐
able See Owner's
Manual Speed Limit Assist is deactivated and temporarily inoperative.
Possible causes:
R
the windscreen is dirty in the camera's field of vision.
R visibility is impaired due to heavy rain, snow or fog.
X Clean the windscreen.
If the system detect sthat the camera is fully operational, the dis-
play message disappears.
Speed Limit Assist is operational again. Speed Limit
Assist: Unavaila‐
ble in this country Speed Limit Assist is only available in certain countries.
X
Drive on.
Speed Limit Assist is available again as soon as you drive in a
country in which its use is approved. Speed Limit Assist
inoperative Speed Limit Assist is faulty.
X
Visit aqualified specialist workshop. 244
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
Lan
eK eeping Assist currently
unavailable See
Owner'
sManual or
Active Lan eKeep‐ ing Assist cur‐
rently unavailable
See Owner'
sManual Lan
eKeepin gAssistorA ctive Lane Keeping Assist is deactivated
and temporaril yinoperative .Possible causes:
R the windscreen is dirty in the camera's field of vision.
R visibility is impaired due to heavy rain, snow or fog.
R there are no lane markings for alonger period.
R the lane markings are worn, dark or covered, e.g. by dirt or snow.
Once the causes listed above no longer apply,t he display message
goes out.
Lane Keeping Assist or Active Lane Keeping Assist is operational
again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 159).
X Clean the windscreen. Lane Keeping
Assist inopera‐
tive or
Active Lane Keeping
Assist inoperative Lane Keeping Assist or Active Lane Keeping Assist is faulty.
X
Visit aqualified specialist workshop. Lane Keeping
Assist currently
unavailable See
Owner's Manual or
Active Lane Keep‐ ing Assist cur‐
rently unavailable
See Owner's Manual Blind Spot Assist or Active Blind Spot Assist is temporarily inop-
erative.
You have established the electrical connection between the trailer
and your vehicle.
X
Press aon the steerin gwheel to confirm the display mes-
sage.
Blind Spot Assist or Active Blind Spot Assist is deactivated while
towing atrailer. 246
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
Blind Spot Assis
torActive Blind Spot Assist is temporaril yinop-
erative .Possible causes:
R the sensors are dirty.
R the function is impaired due to heavy rain or snow.
R the radar sensor system is outside the operating temperature
range.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
The yellow 9indicator lamps also light up in the exterior mir-
rors.
Once the causes listed above no longer apply,t he display message
goes out.
Blind Spot Assist or Active Blind Spot Assist is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 159).
X Clean the sensors (Y page 304).
X Restart the engine. Blind Spot Assist
inoperative or
Active Blind Spot Assist inoperative Blind Spot Assist or Active Blind Spot Assist is faulty.
The yellow
9indicator lamps also light up in the exterior mir-
rors.
X Visit aqualified specialist workshop. Park Assist cancel‐
led The driver's door is open and the driver's seat belt has not been
fastened.
X
Repeat the parking process with the seat belt fastened and the
driver's door closed. You have inadvertently touched the multifunction steerin
gwheel
while steerin gintervention was active.
X While steerin gintervention is active, make sure not to touch the
multifunction steerin gwheel. The vehicle has started to skid and ESP
®
has intervened.
X Use Active Parking Assist again later (Y page 187). Display messages
247On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
Park Assist inoper‐
ative You hav
ejustc arrie doutalarg enumber of turning or parking
manoeuvres.
Active Parking Assis twill become available again after approx-
imately ten minutes (Y page 187).
X Pull over and stop the vehicle safely as soon as possible ,paying
attention to road and traffic conditions.
X Switch off and restart the engine.
If the display message continues to be displayed:
X Visit aqualified specialist workshop. PARKTRONIC is faulty.
X
Visit aqualified specialist workshop. Parking Guidance
finished The vehicle is parked.
Awarning tone also sounds.
The display message disappears automatically. DISTRONIC PLU
Soff DISTRONI
CPLUSh as been deactivate d(Ypage 170).
If it was deactivate dautomatically, awarning tone also sounds. DISTRONIC PLUS
available again DISTRONI
CPLUSiso perational againa fter having been tempo-
rarily unavailable. You can now reactivate DISTRONI CPLUS
(Y page 170). DISTRONIC PLUS cur‐
rently unavailable
See Owner's Manual DISTRONIC PLUS is temporarily inoperative. Possible causes:
R
the function is impaired due to heavy rain or snow.
R the sensor sinthe radiator trim and in the bumpers are dirty.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tion soro ther sources of electromagnetic radiation.
R the system is outside the operatin gtemperature range.
R the on-board voltage is too low.
Aw arning tone also sounds.
Once th ecauses listed abov enolonger apply,t he display message
goes out.
DISTRONIC is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 159).
X Clean the sensors in the radiator trim and in the bumpers
(Y page 304).
X Restart the engine. 248
Display messagesOn-board computer and displays

Tyres
Display messages Possible causes/consequence
sand M Solutions
Tyr
epressure Check tyres The tyr
epressure loss warnin gsystem ha sdetecte das ignificant
loss in pressure.
Aw arning tone also sounds.
G WARNING
Wit htyrep ressure swhicha re to olow, there is ariskoft he fol-
lowing hazards:
R the tyres may burst, especiallyast he load and vehicle speed
increase.
R the tyres may wear excessively and/or unevenly, which may
greatly impair tyre traction.
R the driving characteristics, as well as steering and braking, may
be greatly impaired.
There is arisk of an accident.
X Stop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditionsasy ou do
so.
X Secure the vehicle against rolling away (Y page 159).
X If there is aflat tyre, inspect the tyres (Y page 312).
X Check the tyre pressures and, if necessary, correct the tyre
pressure.
X Restart the tyre pressure loss warning system when the tyre
pressure is correct (Y page 333).Check tyre pres‐
sures
then restart Run
Flat Indicator The tyre pressure loss warning system generated
adisplaym es-
sage and has not been restarted since.
X Set the correct tyre pressure in all four tyres.
X Restart the tyre pressure loss warning system (Y page 333).Run Flat Indicator
inoperative The tyre pressure loss warning system is faulty.
X
Visit aqualified specialist workshop. Tyre pressure
displayed after
driving for
afew minutes The tyre pressure monitor is measuring the tyre pressure.
X
Driv eon.
The tyre pressures appear in the multifunction display after you
have been driving for afew minutes. Tyre press. monitor
inoperative The tyre pressure monitor is faulty.
X
Visit aqualified specialist workshop. 250
Display messagesOn-boar
dcomputer and displays

Display messages Possible causes/consequences and
M Solutions
Tyr
ep ress. moni‐ tor inoperative No
wheel sensors The wheels fitte
ddonot haveasuitable tyr epressure sensor .The
tyre pressure monitor is deactivated.
X Fit wheels with suitable tyre pressure sensors.
The tyre pressure monitor is activated automatically after driv-
ing for afew minutes. Check
tyres The tyre pressure in one or more tyres has dropped significantly.
The wheel position is displayed in the multifunction display.
Aw
arning tone also sounds.
G WARNING
Wit htyrep ressure swhicha re to olow, there is ariskoft he fol-
lowing hazards:
R the tyres may burst, especiallyast he load and vehicle speed
increase.
R the tyres may wear excessively and/or unevenly, which may
greatly impair tyre traction.
R the driving characteristics, as well as steering and braking, may
be greatly impaired.
There is arisk of an accident.
X Stop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditionsasy ou do
so.
X Secure the vehicle against rolling away (Y page 159).
X If there is aflat tyre, inspect the tyres (Y page 312).
X Check the tyre pressure (Y page 334).
X If necessary, correct the tyre pressure. Display messages
251On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
Warning
tyr
ed efect The tyr
epressur einone or more tyre shas dropped suddenly. The
wheel position is displayed in the multifunction display.
G WARNING
If you drive with aflat tyre, there is arisk of the following hazards:
R Af lat tyre affect sthe ability to steer or brake the vehicle.
R You could lose control of the vehicle.
R Continued driving with aflat tyre will cause excessive heat build-
up and possibly afire.
There is arisk of an accident.
X Stop the vehicle without making any sudden steerin gorbraking
manoeuvres. Pay attention to the traffic conditions as you do
so.
X Secure the vehicle against rolling away (Y page 159).
X If there is aflat tyre, inspect the tyres (Y page 312).Rectify
tyre pressure The tyre pressure is too low in at least one of the tyres, or the tyre
pressure differenc
ebetween the wheels is too great.
X Check the tyre pressures at the next opportunity
(Y page 334).
X If necessary, correc tthe tyre pressure.
X Restart the tyre pressure monitor (Y page 335).Wheel sensor(s)
missing There is no signal from the tyre pressure sensor of one or several
wheels. The pressure of the affected tyre is not displayed in the
multifunction display.
X
Have the faulty tyre pressure sensor replaced at aqualified spe-
cialist workshop. Tyre press. monitor
currently unavail‐
able Due to
asource of radio interference, no signals can be received
from the wheel sensors. The tyre pressure monitor is temporarily
malfunctioning.
X Drive on.
The tyre pressure monitor restart sautomatically as soon as the
cause has been rectified. 252
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
h
Tyr
ep ressure Cau‐ tio
nT yrem alfunc‐ tion The tyr
epressur einoneor mor etyres has dropped suddenly.
Aw arning tone also sounds.
G WARNING
If you driv ewithaf lat tyre, there is ariskoft he following hazards:
R Af lat tyre affects the ability to steer or brake the vehicle.
R You could lose control of the vehicle.
R Continued driving with aflat tyre will cause excessive heat build-
up and possibly afire.
There is arisk of an accident.
X Stop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditionsasy ou do
so.
X Secure the vehicle against rolling away (Y page 159).
X If there is aflat tyre, inspect the tyres (Y page 312).h
Tyre pressure
Check tyre(s) The tyre pressure in one or more tyres has dropped significantly.
G WARNING
With tyre pressures which are too low, there is arisk of the fol-
lowing hazards:
R the tyres may burst, especiallyast he load and vehicle speed
increase.
R they tyres may wear excessively and/or unevenly, which may
greatly impair tyre traction.
R the driving characteristics, as well as steering and braking, may
be greatly impaired.
There is arisk of an accident.
X Stop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditionsasy ou do
so.
X Secure the vehicle against rolling away (Y page 159).
X If there is aflat tyre, inspect the tyres (Y page 312).
X Check the tyre pressure (Y page 334).
X If necessary, correct the tyre pressure. h
Please correct
tyre pressure The tyre pressure is too low in at least one of the tyres, or the tyre
pressure difference between the wheels is too great.
X
Check the tyre pressures at the next opportunity
(Y page 334).
X If necessary, correct the tyre pressure. Display messages
253On-board computer and displays Z