ECU MERCEDES-BENZ GLA-Class 2017 X156 Service Manual

Display messagesPossible causes/consequences andMSolutions
Front Passenger
Airbag Disabled
SeeOperator'sMan‐
ual
The front-passenger air bag and front-passenger knee bag are
deactivated during th ejourney, although:
Ran adult
or
Raperson of th ecorrespondin gstature is on th efront-passenger
seat
If additional forces are applied to th eseat ,th esystem may inter-
pre tth eoccupant's weight as lowe rthan it actually is.
GWARNIN G
The front-passenger fron tair bag and fron tpassenger knee bag
may no tbe triggered in th eevent of an accident.
There is an increase dris kof injury.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 171).
XSwitchth eignition off.
XHav eth eoccupant get out of th evehicle.
XKee pth eseat unoccupied ,close th efront-passenger doo rand
switch on th eignition .
XObserveth ePASSENGER AI RBA Gindicato rlamp sin th ecenter
console and th emultifunction display and chec kth efollowing :
Seat unoccupied and ignition switched on :
Raself-diagnosi sis carrie dout .The PASSENGER AI RBA GOF F
and PASSENGER AI RBA GON indicato rlamp smus tligh tup
simultaneousl yfo rapproximately six s
econds
RthePASSENGER AI RBA GOF Findicato rlamp mus tthen ligh t
up and remain lit after th eself-diagnosis. If th eindicato rlamp
is on ,OCS (Occupant Classification System) has disabled th e
front-passenger fron tair bag and front-passenger knee bag
(
Ypage 51)
Rth eFront Passenger Air Bag Enable dSee Opera‐
tor's Manualor Front Passenger Air Bag Disabled
See Operator' sManualdisplay message smus tno tbe
shown in th emultifunction display
XWait fo r aperiod of at leas t60 seconds until th enecessar ysys-
te m checks hav ebeen completed.
XMak esur ethat th edisplay message sdo no tappea rin th emul-
tifunction display.
If these condition sare fulfilled ,th efront-passenger seat can be
occupied again .Whether th ePASSENGER AI RBA GOF For ON
Display messages24 5
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
indicatorlamp remain slit or goe sout depend son how OCS clas-
sifies th eoccupant .
If th econdition sare no tfulfilled ,th esystem is no toperating cor-
rectly.
XVisit aqualified specialist workshop immediately.
Fo rfurther information about th eOccupant Classification System,
see (
Ypage 51) .
Front Passenger
AirbagEnabledSee
Operator' sManual
The front-passenger air bag and front-passenger knee bag are
enabled during th ejourney, eve nthough :
Rachild, asmall adult or an objec tweighin gless than th esys-
tem' sweight threshold is locate don th efront-passenger seat
or
Rth efront-passenger seat is unoccupied
The system may detec tobjects or forces applying additional
weight on th eseat .
GWARNIN G
The front-passenger fron tair bag and front-passenger knee bag
may be triggered unintentionally.
There is an increase dris kof injury.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 171).
XSwitchth eignition off.
XOpe nth efront-passenger door.
XRemove th echild and th echild restrain tsystem from th efront-
passenger seat .
XMakesur ethat there are no objects on th eseat addin gto th e
weight .
The system may otherwise detec tth eadditional weight and
interpret th eseat occupant's weight as greate rthan it actually
is.
XKee pth eseat unoccupied ,close th efront-passenger doo rand
switch on th eignition .
XObserveth ePASSENGER AI RBA Gindicato rlamp sin th ecenter
console and th emultifunction display and chec kth efollowing :
246Display messages
On-board computer and displays

Engine
Display messagesPossible causes/consequences andMSolutions
+
Check Coolant
Level See Opera‐
tor'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 311).
If you have to add coolant frequently:
XContact a qualified specialist workshop and have the engine
cooling system checked.
?The fan motor is faulty.
XAt coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic.
?
Coolant Too Hot
Stop Vehicle Turn
Engine Off
The coolant is too hot.
A warning tone also sounds.
GWARNING
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Steam from 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 171).
XWait until the engine has cooled down.
XMake sure that the 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 †). Other-
wise, the engine could be damaged.
XPay attention to the coolant temperature display.
If the temperature increases again:
XVisit a qualified specialist workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 248 ‡ (120†) .
Displa y messages251
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
#
SeeOperator'sMan‐
ual
The battery is no tbein gcharged.
A warnin gtone also sounds.
Possibl ecauses are:
Radefective alternato r
Ratorn poly-V-belt
Ramalfunction in th eelectronics
!Do no tcontinue driving. The engin ecould otherwise overheat .
XPull overand stop th evehicl esafely and switch of fth eengine,
payin gattention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 171).
XConsult aqualified specialist workshop .
#
StopVehicl eSee
Operator' sManual
The battery is no longer bein gcharged and th ebattery charg elevel
is to olow.
A warnin gtone also sounds.
XPull ove rand stop th evehicl esafely and switch of fth eengine,
payin gattention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 171).
XObserv eth einstruction sin th edisplay message #See
Operator' sManual.
XConsult aqualified specialist workshop .
4
Check Engine Oil
At NextRefueling
The engin eoil level has dropped to th eminimum level.
A warnin gtone also sounds.
!Avoid lon gjourneys wit hto olittl eengin eoil. The engin ewill
otherwise be damaged.
XChec kth eoil level when next refueling, at th elatest
(
Ypage 310).
XIf necessary, add engin eoil (Ypage 310).
If th eengin eoil need stopping up more often:
XContac t aqualified specialist workshop and hav eth eengin e
checked.
Information on approve dengin eoils can be obtained from any
qualified specialist workshop or on th eInternet at http:/ /
bevo.mercedes-benz.co m.
æ
Fuel Level Low
The fuel level has dropped into the reserve range.
XRefuel at the nearest gas station.
252Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
LaneKeepin g
Assist Currently
Unavailable See
Operator' sManual
Lan eKeepin gAssis tis deactivated and temporarily inoperative.
Possibl ecauses are:
Rth ewindshield in th ecamera' sfield of vision is dirty.
Rvisibility is impaire ddue to heav yrain ,snow or fog.
Rthere hav ebeen no lan emarking sfo ran extended period.
Rth elan emarking sare worn, dark or covered, e.g. by dir tor snow.
Whe nth ecauses state dabov eno longer apply, th edisplay mes -
sage disappears.
Lan eKeepin gAssis tis operational again .
If th edisplay message does no tdisappear :
XPull overand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 171).
XClean th ewindshield.
Lan eKeepin g
Assist Inoperative
LaneKeepin gAssis tis faulty.
XVisit aqualified specialist workshop .
Blind SpotAssist
Currently Unavail‐
abl eSee Opera‐
tor's Manual
Blind Spot Assis tis temporarily inoperative.
Possibl ecauses are:
Rth erada rsensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radi osta-
tion sor other source sof electromagnetic radiation .
Rtherada rsensor system is outside th eoperating temperature
range.
The yello w9 indicato rlamp salso ligh tup in th eexterio rmir -
rors.
Whe nth ecauses state dabov eno longer apply, th edisplay mes -
sage disappears.
Blind Spot Assis tis operational again .
If th edisplay message does no tdisappear :
XPull overand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 171).
XRestart th eengine.
Blind Spo tAssist
Inoperative
Blind Spot Assis tis defective.
The yello w9 indicato rlamp salso ligh tup in th eexterio rmir -
rors.
XVisit aqualified specialist workshop .
254Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
DISTRONICPLUSCur‐
rentlyUnavailable
SeeOperator' sMan‐
ual
DISTRONIC PLU Sis temporarily inoperative.
Possibl ecauses are:
Rth erada rsensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radi osta-
tion sor other source sof electromagnetic radiation .
Rthesystem is outside th eoperating temperature range.
Rth eon-boar dvoltag eis to olow.
A warnin gtone also sounds.
Whe nth ecauses state dabov eno longer apply, th edisplay mes -
sage disappears.
DISTRONIC PLU Sis operational again .
If th edisplay message does no tdisappear :
XPull overand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 171).
XRestart th eengine.
DISTRONIC PLU S
Inoperative
DISTRONIC PLUSis defective. Adaptive Brake Assis tmay also
hav efailed.
A warnin gtone also sounds.
XVisit aqualified specialist workshop .
DISTRONICPLUSSus‐
pended
You hav edepressed th eaccelerato rpedal .DISTRONIC PLU Sis no
longer controllin gth espeed of th evehicle.
XRemove your foot from th eaccelerato rpedal .
DISTRONIC PLU S
- - -mph
An activation condition fo rDISTRONIC PLU Sis no tfulfilled .
XCheckth eactivation condition sfo rDISTRONIC PLU S
(
Ypage 186).
256Display messages
On-board computer and displays

Tires
Display messagesPossible causes/consequences andMSolutions
Check Tire Pres‐
sure Soon
Canada only:
The tire pressure loss warning system has detected a significant
loss in pressure.
A warning tone also sounds.
Possible causes:
Ryou have changed the positions of the wheels and tires or instal-
led new wheels and tires.
Rthe tire pressure in one or more tires has dropped
GWARNING
Tire pressures that are too low pose the 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 171).
XCheck the tires and, if necessary, follow the instructions for a
flat tire (
Ypage 322).
XCheck the tire pressures and, if necessary, correct the tire pres-
sure.
XRestart the tire pressure loss warning system when the tire
pressure is correct (
Ypage 347).
Check Tire Pres‐
sure Then Restart
Run Flat Indicator
Canada only:
The tire pressure loss warning system generated a display mes-
sage and has not been restarted since.
XSet the correct tire pressure in all four tires.
XRestart the tire pressure loss warning system (Ypage 347).
RunFlatIndicator
Inoperative
Canada only:
The tire pressure loss warning system is faulty.
XVisit a qualified specialist workshop.
258Displa y messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
Please Correct
TirePressure
US Aonly:
The tire pressur eis to olow in at leas ton eof th etires ,or th etire
pressur edifference between th ewheels is to ogreat.
XChec kth etire pressures at th enext opportunity (Ypage 348).
XIf necessary, correc tth etire pressure.
XRestart th etire pressur emonitor (Ypage 350).
Check TiresUSAonly:
The tire pressur ein on eor mor etires has dropped significantly.
The whee lposition appears in th emultifunction display.
A warnin gtone also sounds.
GWARNIN G
Tirepressures that are to olow pos eth efollowing hazards :
Rthey may burst, especially as th eload and vehicl espeed
increase .
Rthey may wear excessivel yand/o runevenly, whic hmay greatl y
impair tire traction .
Rthedrivin gcharacteristics ,as well as steerin gand braking, may
be greatl yimpaired.
There is aris kof an accident.
XStop th evehicl ewithout makin gany sudden steerin gor brakin g
maneuvers .Pay attention to th etraffic condition sas you do so.
XSecur eth evehicl eagainst rollin gaway (Ypage 171).
XCheckth etires and ,if necessary, follow th einstruction sfo r a
flat tire (
Ypage 322).
XCheckth etire pressur e (Ypage 348).
XIf necessary, correc tth etire pressure.
Display messages25 9
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
WarningTir eMal ‐
function
USAonly:
The tire pressur ein on eor mor etires has dropped suddenly. The
whee lposition appears in th emultifunction display.
GWARNIN G
Drivingwit h a flat tire poses aris kof th efollowing hazards :
Raflat tire affects th eabilit yto steer or brak eth evehicle.
Ryou could los econtrol of th evehicle.
Rcontinued drivin gwit h a flat tire will caus eexcessive heat build-
up and possibl y afire.
There is aris kof an accident.
XStop th evehicl ewithout makin gany sudden steerin gor brakin g
maneuvers .Pay attention to th etraffic condition sas you do so.
XSecur eth evehicl eagainst rollin gaway (Ypage 171).
XCheckth etires and ,if necessary, follow th einstruction sfo r a
flat tire (
Ypage 322).
TirePress. Moni‐
tor Currently
Unavailable
US Aonly:
Becaus ethere is interferenc efrom astron gsource of radi owaves,
no signal sfrom th etire pressur esensor sare detected. The tire
pressur emonitor is temporarily malfunctioning.
XDrive on .
The tire pressur emonitor restarts automatically as soo nas th e
problem has been resolved.
TirePress .Sen ‐
sor(s) Missin g
USAonly:
There is no signal from th etire pressur esensor of on eor several
wheels. The pressur eof th eaffecte dtire does no tappea rin th e
multifunction display.
XHav eth efault ytire pressur esensor replaced at aqualified spe -
cialist workshop .
TirePressure Mon ‐
itorInoperative
No Wheel Sensor s
USAonly:
The wheels mounted do no thav e a suitable tire pressur esensor .
The tire pressur emonitor is deactivated.
XMoun twheels wit hsuitable tire pressur esensors.
The tire pressur emonitor is activated automatically after drivin g
fo r a few minutes.
Tir ePress. Moni‐
tor Inoperative
US Aonly:
The tire pressur emonitor is faulty.
XVisit aqualified specialist workshop .
260Display messages
On-board computer and displays

Vehicle
Display messagesPossible causes/consequences andMSolutions
Depress Brake to
Start Engine
You have attempted to start the engine with the transmission in
positionNwithout depressing the brake pedal.
XDepress the brake pedal.
To Deselect P or
N, Depress Brake
and Start Engine
You have attempted to shift the transmission to position Ror D
without starting the engine.
XStart the engine.
XDepress the brake pedal.
iIt is only possible to shift the transmission from position Pto
the desired position if you depress the brake pedal. Only then
can the parking lock be deactivated. If you do not depress the
brake pedal, the DIRECT SELECT lever can still be moved but the parking lock remains engaged.
iAt transmission fluid temperatures below Ò4‡( Ò20 †) you can
only shift out of position Pinto another transmission position
when the engine is running.
Apply Brake to
Shift from 'P'
You have attempted to shift the transmission to position R,Nor D
without depressing the brake pedal.
XDepress the brake pedal.
Transmission Not
in P Risk of Vehi‐
cle Rolling Away
The driver's door is open or not fully closed and the transmission
is in position R,Nor D.
A warning tone also sounds.
GWARNING
The vehicle may roll away.
There is a risk of an accident.
XShift the transmission to position P.
XSecure the vehicle against rolling away (Ypage 171).
XClose the driver's door completely.
Display messages261
On-board computer and displays
Z