ECU MERCEDES-BENZ CLA 2014 Owner's Guide

Display messagesPossible causes/consequences and
Solutions
The red(USA only)/ (Canada only) indicatorlamp
flashes and the yellow warning lamp lights up.
The electric parking brake is malfunctioning.
To release:
XSwitch off the ignition and turn it back on.
XRelease the electric parking brake manually.
To apply:
XSwitch off the ignition and turn it back on.
XApply the electric parking brake manually.
If the red(USA only)/ (Canada only) indicator lamp
continues to flash:
XDo not drive on.
XSecure the vehicle against rolling away (Ypage 337).
XShift the transmission toP.
XTurn the frontwheels towards the curb.
XConsult a qualified specialist workshop.
The yellow warning lamp lights up. The red(USA
only)/ (Canada only) indicator lamp flashes for about ten
seconds after the electric parking brake has been applied or
released. It then goes out or remains lit.
The electric parking brake is malfunctioning.
XSwitch off the ignition and turn it back on.
XApply the electric parking brake.
If it is not possible to engage the electric parking brake:
XShift the transmission toP.
XVisit a qualified specialist workshop.
If it is not possible to release the electric parking brake:
XRelease the electric parking brake automatically (Ypage 154).
If the electric parking brake still cannot be released:
XConsult a qualified specialist workshop.
Display messages217
On-board computer and displays
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Display messagesPossible causes/consequences and
Solutions
(USA
only)(Canada
only)
Check Brake Fluid
Level
There is notenough brake fluid in the brake fluid reservoir.
In addition, the(USA only)/(Canada only) warning
lamp lights up in the instrument cluster and a warning tone
sounds.
GWARNING
The braking effect may be impaired.
There is a riskofanaccident.
XPull overand stop the vehicle safely as soonas possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
XSecure the vehicle against rolling away (Ypage 153).
XConsult a qualified specialist workshop.
XDo not add brake fluid. This does not correct the malfunction.

Check Brake Pad
Wear
The brake pads/linings have reached their wear limit.
XVisit a qualified specialist workshop.

mbrace Inoperative
One or more main features of the mbrace system are
malfunctioning.
XHave the mbrace system checked immediately at a qualified
specialist workshop.

SRS Malfunction
Service Required
There is a malfunction in the SRS (Supplemental Restraint
System). Thewarning lamp also lights up in the instrument
cluster.
GWARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
XVisit a qualified specialist workshop.
Further information on occupant safety (Ypage 38).
Display messages219
On-board computer and displays
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Display messagesPossible causes/consequences and
Solutions
Front Passenger
Airbag Disabled
See Operator's
Manual
The front-passenger air bag is disabled during the journey, even
though:
Ran adult
or
Ra person larger than a certain size is occupying the front-
passenger seat
If additional forces are applied to the seat, the system may
interpret the occupant's weight as lowerthan it actually is.
GWARNING
The front-passenger air bag does not deploy during an accident.
There is an increased risk of injury.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 153).
XSwitch the ignition off.
XHave the occupant get out of the vehicle.
XKeep the seat unoccupied, close the front-passenger door and
switch on the ignition.
XObserve the PASSENGER AIR BAG OFF indicator lamp in the
center console and the multifunction display and check the
following:
Seat unoccupied and ignition switched on:
Rthe PASSENGER AIR BAG OFF indicator lamp must light up and
remain lit. If the indicator lamp is on, OCS has disabled the front-
passenger air bag (Ypage 45).
RtheFront Passenger Airbag Enabled See Operator's
ManualorFront Passenger Airbag Disabled See
Operator's Manualdisplay messages must not be shown in
the multifunction display.
XWait for a period of at least 60 seconds until the necessary
system checks have been completed.
XMake sure that the display messages do not appearinthe
multifunction display.
If these conditions are fulfilled, the front-passenger seat can be
occupied again. Whether the PASSENGER AIR BAG OFF indicator
lamp remains lit or goes out depends on how OCS classifies the
occupant.
If the conditions are not fulfilled, the system is not operating
correctly.
XVisit a qualified specialist workshop immediately.
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On-board computer and displays
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Display messagesPossible causes/consequences and
Solutions
Forfurther information about the OccupantClassification System,
see (Ypage 45).
Front Passenger
AirbagEnabledSee
Operator's Manual
The front-passenger air bag is enabled during the journey, even
though:
Ra child, a small adult or an object weighing less than the
system's weight threshold is located on the front-passenger
seat
or
Rthe front-passenger seat is unoccupied
The system may detect objects or forces applying additional
weight on the seat.
GWARNING
The air bag may deploy unintentionally.
There is an increased risk of injury.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 153).
XSwitch the ignition off.
XOpen the front-passenger door.
XRemove the child and the child restraint system fromthe front-
passenger seat.
XMake sure that there are no objects on the seat adding to the
weight.
The system may otherwise detect the additional weight and
interpret the seat occupant's weight as greater than it actually
is.
XKeep the seat unoccupied, close the front-passenger door and
switch on the ignition.
XObserve the PASSENGER AIR BAG OFF indicator lamp in the
center console and the multifunction display and check the
following:
Seat unoccupied and ignition switched on:
Rthe PASSENGER AIR BAG OFF indicator lamp must light up and
remain lit. If the indicator lamp is on, OCS (Occupant
Classification System) has disabled the front-passenger air bag
(Ypage 45).
RtheFront Passenger Airbag Enabled See Operator's
ManualorFront Passenger Airbag Disabled See
Operator's Manualdisplay messages must not be shown in
the multifunction display.
222Display messages
On-board computer and displays

Engine
Display messagesPossible causes/consequences and
Solutions

Check Coolant See
Operator's Manual
The coolant level is too low.
!Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
XAdd coolant, observing the warning notes before doing so
(Ypage 283).
XIf coolant needs to be added more often than usual, have the
engine coolant system checked at a qualified specialist
workshop.
\rThe fan motor is faulty.
XAt coolant temperatures below 248 ‡ (120 †), drive to the
nearestqualified specialist workshop.
XAvoid subjecting the engineto heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic.
\r
Coolant Too Hot
Stop Vehicle Turn
Engine Off
The coolant is too hot.
Awarning tone also sounds.
GWARNING
Do notdrive when yourengine is overheated. Thiscan cause some
fluids which may have leaked into the engine compartmentto
catch fire.
Steamfrom the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury.
XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 153).
XWaituntil the engine has cooled down.
XMake sure thatthe air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
XDo not start the engine again until the display message goes out
and the coolant temperature is below 248 ‡ (120 †).
Otherwise, the engine could be damaged.
XPay attention to the coolant temperature display.
XIf the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 248 ‡ (120 †).
Display messages227
On-board computer and displays
Z

Display messagesPossible causes/consequences and
Solutions
SpeedLimitAssist
Inoperative
Speed Limit Assistis faulty.
XVisit a qualified specialist workshop.

Off
The HOLD function is deactivated. The vehicle is skidding.
Awarning tone also sounds.
XReactivate the HOLD function later (Ypage 172).
The HOLD function is deactivated. When the brakepedal is firmly
depressed, an activation condition is not fulfilled.
Awarning tone also sounds.
XCheck the activation conditions for the HOLD function
(Ypage 172).
Radar Sensors
Deactivated See
Operator's Manual
The radar sensor system is deactivated.
XSwitch on the radar sensor system (Ypage 208).
Lane Keeping
Assist Currently
Unavailable See
Operator's Manual
Lane Keeping Assist is deactivated and temporarily inoperative.
Possible causes are:
Rthe windshield in the camera's field of vision is dirty.
Rvisibility is impaired due to heavy rain, snow or fog.
Rthere are no lane markings for a longer period.
Rthe lane markings are worn, dark or covered, e.g.by dirtorsnow.
Whenthe causes stated above no longer apply, the display
message disappears.
Lane Keeping Assist is operational again.
If the display message does not disappear:
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 153).
XCleanthe windshield.
Lane Keeping
Assist Inoperative
Lane Keeping Assist is faulty.
XVisit a qualified specialist workshop.
230Display messages
On-board computer and displays

Display messagesPossible causes/consequences and
Solutions
Blind Spot Assist
Currently
Unavailable See
Operator's Manual
Blind Spot Assistis temporarily inoperative. Possible causes are:
Rthe sensors are dirty.
Rfunction is impaired due to heavy rain or snow.
Rthe radar sensor system is outside the operating temperature
range.
Rthe radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio
stations or other sources of electromagnetic radiation.
The yellowindicator lamps also light up in the exterior
mirrors.
When the causes stated above no longer apply, the display
message disappears.
Blind Spot Assist is operational again.
If the display message does not disappear:
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 153).
XCleanthe sensors (Ypage 289).
XRestart the engine.
Blind Spot Assist
Inoperative
Blind Spot Assist is defective.
The yellowindicator lamps also light up in the exterior
mirrors.
XVisit a qualified specialist workshop.
Park Assist
Canceled
The driver's door is open and the driver's seat belt has not been
fastened.
XRepeatthe parking process with the seat belt fastened and the
driver's door closed.
You have inadvertently touched the multifunction steering wheel
while steering intervention was active.
XWhile steering intervention is active, make sure that the
multifunction steering wheel is not touched unintentionally.
The vehicle has started to skid and ESP®has intervened.
XUse Active Parking Assist again later (Ypage 178).
Display messages231
On-board computer and displays
Z

Display messagesPossible causes/consequences and
Solutions
Park Assist
Inoperative
You have just carried out a large number of turning or parking
maneuvers.
Active Parking Assistwill become available again after
approximately ten minutes (Ypage 178).
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
XSwitch off and restart the engine.
If the display message continues to be displayed:
XVisit a qualified specialist workshop.
PARKTRONIC is defective.
XVisit a qualified specialist workshop.
DISTRONIC PLUS OffDISTRONIC PLUS has been deactivated (Ypage 164). If it was
deactivated automatically, a warning tone also sounds.
DISTRONICPLUSNow
Available
DISTRONIC PLUS is operational again after having been
temporarily unavailable. You can now reactivate DISTRONIC PLUS
(Ypage 164).
DISTRONIC PLUS
Currently
Unavailable See
Operator's Manual
DISTRONIC PLUS is temporarily inoperative. Possible causes are:
Rfunction is impaired due to heavy rain or snow.
Rthe sensors in the radiator trim are dirty
Rthe radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio
stations or other sources of electromagnetic radiation.
Rthe system is outside the operating temperature range.
Rthe on-board voltage is too low.
Awarning tone also sounds.
When the causes stated above no longer apply, the display
message disappears.
DISTRONIC is operational again.
If the display message does notdisappear:
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 153).
XClean the sensors in the radiator trim (Ypage 289).
XRestartthe engine.
232Display messages
On-board computer and displays

Tires
Display messagesPossible causes/consequences and
Solutions
Check
Tire Pressure Soon
Canada only:
The tire pressure loss warningsystem has detected a significant
loss in pressure.
Awarning tone also sounds.
GWARNING
With tire pressures which are too low, there is a riskofthe
following hazards:
Rthey may burst, especially as the load and vehicle speed
increase.
Rthey may wear excessively and/or unevenly, which may greatly
impair tire traction.
Rthe driving characteristics, as well as steering and braking, may
be greatly impaired.
There is a risk of an accident.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.
XSecure the vehicle against rolling away (Ypage 153).
XCheck the tires and, if necessary, follow the instructions for a
flat tire (Ypage 295).
XCheck the tire pressures and, if necessary, correct the tire
pressure.
XRestart the tire pressure loss warning system when the tire
pressure is correct (Ypage 319).
CheckTirePressure
Then Restart Run
Flat Indicator
Canada only:
The tire pressure loss warning system generated a display
message and has not been restarted since.
XSet the correct tire pressure in all four tires.
XRestart the tire pressure loss warning system (Ypage 319).
RunFlatIndicator
Inoperative
Canada only:
The tire pressure loss warning system is faulty.
XVisit a qualified specialist workshop.
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.
XCheck the tire pressures at the next opportunity (Ypage 320).
XIf necessary, correct the tire pressure.
XRestart the tire pressure monitor (Ypage 322).
234Display messages
On-board computer and displays

Display messagesPossible causes/consequences and
Solutions
Check TiresThe tire pressure in one or more tires has dropped significantly.
The wheel position is displayed in the multifunction display.
Awarning tone also sounds.
GWARNING
With tire pressures which are too low, there is a riskofthe
following hazards:
Rthey may burst, especially as the load and vehicle speed
increase.
Rthey may wear excessively and/or unevenly, which may greatly
impair tire traction.
Rthe driving characteristics, as well as steering and braking, may
be greatly impaired.
There is a risk of an accident.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.
XSecure the vehicle against rolling away (Ypage 153).
XCheck the tires and, if necessary, follow the instructions for a
flat tire (Ypage 295).
XCheck the tire pressure (Ypage 320).
XIf necessary, correct the tire pressure.
Warning Tire
Malfunction
The tire pressure in one or more tires has dropped suddenly. The
wheel position is shown in the multifunction display.
GWARNING
If you drive with a flat tire, there is a risk of the following hazards:
Ra flat tire affects the ability to steer or brake the vehicle.
RYou could lose control of the vehicle.
Rcontinued driving with a flat tire will cause excessive heat build-
up and possibly a fire.
There is a risk of an accident.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.
XSecure the vehicle against rolling away (Ypage 153).
XCheck the tires and, if necessary, follow the instructions for a
flat tire (Ypage 295).
Display messages235
On-board computer and displays
Z