PLUG‑IN HYBRID operation
Points to remember
General notes
Hybrid technology combines a fuel efficient
internal combustion engine with a powerful
electric motor. In HYBRIDmode, the hybrid
drive system automatically selects the most effi-
cient operating mode for every driving situation. Drive the vehicle in the usual manner.
To save fuel in HYBRIDmode, the hybrid drive
system switches off the combustion engine as
often as possible during the journey when power
output requirements are low. When power out-
put requirements are low, the electric motor
powers the vehicle. The combustion engine is
automatically activated when power output
requirements are high. The engine is usually
switched off when the vehicle is stationary. Con-
sequently, there is usually no engine idling as
with combustion engine vehicles.
For pulling away and accelerating, the electric
motor supports the internal combustion engine
using the power stored in the high-voltage bat-
tery. In addition, the power is used for partially
electric driving, operation of the electric coolant
compressor and to support the 12 V on-board
electrical system. In this way the hybrid drive
system helps to reduce your vehicle's fuel con-
sumption.
Observe the driving tips on PLUG-IN HYBRID
operation (
Ypage 251).
Recuperative Brake System
If you release the accelerator pedal when the
vehicle is in motion, overrun recuperation is ini-
tiated. The electric motor is operated as a gen-
erator when in overrun mode and when you
brake. Hybrid technology converts the kinetic
energy of the vehicle into electricity and stores
it in the high-voltage battery.
Observe the important safety notes for the
Recuperative Brake System (
Ypage 44).
Important safety notes
If the engine is switched off by the ECO start/
stop function and you open the driver's door:
Ra message appears in the multifunction dis-
play and
Ra warning tone sounds
Further information (
Ypage 297).
All of the vehicle's systems remain active, if:
Rthe vehicle is stationary
Rthe combustion engine is switched off and
Rthe READY indicator in the instrument cluster
lights up
If you remove your foot from the brake pedal
while in transmission position D or R, the vehicle
may pull away automatically.
Observe the notes on the READY display of the
ECO start/stop function (
Ypage 252).
Vehicles with an electric motor generate much
less driving noise than vehicles with internal
combustion engines. As a result, your vehicle
may not be heard by other road users in certain
situations.
Depending on the vehicle's equipment and
country-specific regulations, the vehicle can be
equipped with Acoustic Vehicle Indication.
Acoustic Vehicle Indication generates a certain
sound at a speed between 0 and 19 mph
(30 km/h). This helps other road users, partic-
ularly pedestrians and cyclists, to hear your
vehicle better. The sound can also be heard
inside the vehicle.
The volume depends on the engine speed. The
faster you accelerate, the louder the sound is. At
a speed of over 19 mph (30 km/h) the sound is switched off. Above this speed, the natural
sounds from the vehicle are sufficient that it can
be heard in good time by other road users.
240PLUG‑IN HYBRID operation
Driving and parking
Instrument cluster
:Recuperative Brake Systemwarning lamp (Ypage 315)
;Electric motor performance display (Ypage 242)
=Condition of charge display for high-voltage battery (Ypage 245)
?Drivingmod edisplay (Ypage 243)
AElectrical range
Displays and operation
Electric motor performance display
The power display for th eelectric motor is loca-
te don th eright-hand side of th einstrumen t
cluster.
The curren tcondition of charge of th ehigh-volt -
age battery is shown as apercentage in condi-
tion of charge display A.100% correspond sto
th ehighest possible charge level of th ehigh -
voltag ebattery. Ther
eare two further areas locate dto th elef t
and right of condition of charge display A:
RArea:to; (E-DRIVE):
This shows th eelectric output from th eelec -
tric motor, e.g. during electric operation or in
boos tmode.
When th emotor is switched on ,th edisplay is
at lower limi t;. Withincreasing pressur eon
th eaccelerato rpedal th edisplay fill sup
from ;to:.
Driving with th eelectri cmotor: when th e
display reaches upper limi t:, thecombus -
tion engin eis switched on .If th edisplay is
approachin gupper limi t: and you remove
your foo tfrom th eaccelerato rpedal ,th edis-
play empties again .The combustion engin eis
no tswitched on .At low speeds, you can
thereby control th eelectric operation usage
so that you only driv ein electric mode.
Driving with th ecombustion engine: the
electric motor support sth ecombustion
engin eby providing addit iona
l torque (boost
mode) until th edisplay reaches upper
limi t:.
242PLUG‑ IN HYBRID operation
Driving and parking
a generator and stores the recovered energy
in the high-voltage battery
Rwhen the brakes are applied lightly, the vehi-
cle is slowed down further by the electric
motor. This increases the energy recovery
taking place (
Ypage 240). The electric motor
operates as a generator and stores the recov-
ered energy in the high-voltage battery
Rwhen the brakes are applied with greater
force, the service brakes are also used to slow
the vehicle down. The two systems work
together
Urban driving
Energy is recuperated during frequent deceler-
ation and stopping in city traffic.
The vehicle can be driven by the electric motor
alone up to a speed of approximately 81 mph
(130 km/h).
The vehicle is driven by the electric motor alone
only when all conditions for the automatic
engine switch-off are fulfilled.
Further information on the automatic engine
switch-off (
Ypage 252).
Driving on inter-urban roads
The following phases are possible when driving
on inter-urban roads:
Rrapid acceleration (boost mode)
Rconstant energy consumption
Renergy recuperation
Relectric operation mode
A great deal of recovered energy may be avail-
able, depending on the route profile. This
reduces consumption and emissions.
Highway driving
During highway driving, fuel consumption and
emissions are favorably influenced in particular
by reduced power losses.
The internal combustion engine will be switched
off automatically, if:
Rthe driver removes his or her foot from the
accelerator pedal in drive program Eand a
speed of 81 mph (130 km/h) is not exceeded
Rthe driver removes his or her foot from the
accelerator pedal in drive program E+and a
speed of 112 mph (180 km/h) is not excee-
ded
Further information on the automatic engine
switch-off (
Ypage 252).
ECO start/stop function
General notes
The ECO start/stop function switches the inter- nal combustion engine off automatically when
the vehicle stops moving and at high speeds
(
Ypage 253).
All vehicle systems remain active, e.g. the auto-
matic climate control.
The ECO start/stop function is only available in
drive programs Eand E+. Electric-only operation
is only possible in drive programs Eand E+.
Additional information for drive programs Eand
E+ (
Ypage 250).
Automatic engine switch-off
The engine is switched off automatically, includ-
ing when:
Rthe driver removes his or her foot from the
accelerator pedal in drive program Eand a
speed of 81 mph (130km/ h)is not exceeded
(
Ypage 253)
Rthe driver removes his or her foot from the
accelerator pedal in drive program E+and a
speed of 112 mph (180 km/h) is not excee-
ded (
Ypage 253)
Rthe engine has reached its operating temper- ature
Rthe driver’s seat belt is fastened and the
driver’s door is closed
Rthe driver only slightly depresses the accel-
erator pedal in order to, for example, maintain
the current speed for a limited distance
Rthe hood is closed and engaged properly
Rthe high-voltage battery is charged suffi-
ciently
Rno malfunctions are present in the hybrid
drive system
The internal combustion engine will not be
switched off automatically, if:
Rthe self-diagnosis function of the engine con-
trol unit is still active
Rthere is a malfunction in the hybrid drive sys-
tem
Rthe climate control of the vehicle requires it
Rthe high-voltage battery is being charged
(Ypage 246)
Rautomatic emissions tests are running
252PLUG‑IN HYBRID operation
Driving and parking
Display messagesPossible causes/consequences andMSolutions
F(USA
only)
!( Canada
only)
Parkin gBrake Inop‐
erativ e
The yellow !warning lamp lights up. The red F(USAonly)
or ! (Canada only) indicator lamp flashes for about te nseconds
after th eelectric parking brak ehas been applie dor released. It then
goe sout or remain slit .
The electric parking brak eis malfunctioning ,e.g. because of over-
voltag eor undervoltage.
XRemove th ecaus efor th eovervoltage or undervoltage, e.g. by
charging th ebattery or restarting th eengine.
XEngage or release th eelectric parking brake.
If it remain simpossible to apply or release th eelectric parking brake:
XSwitc hoff th eignition and tur nit bac kon .
XEngage or release th eelectric parking brake.
If th eelectric parking brak estill canno tbe released:
XConsult aqualified specialist workshop .
If th eelectric parking brak estill canno tbe applied:
XVisit aqualified specialist workshop .
The yellow!warning lamp lights up and th ered F (USAonly)
or ! (Canada only) indicator lamp flashes .
It is no tpossibl eto apply th eelectric parking brak emanually.
XShift th etransmission to position P.
XVisitaqualified specialist workshop .
$(USA
only)
J( Canada
only)
Check Brake Fluid
Level
There is no tenough brak eflui din th ebrak efluid reservoir .
In addition ,th e$ (USAonly) or J(Canada only) warning lamp
lights up in th einstrumen tcluste rand awarning tone sounds.
GWARNIN G
The braking effec tmay be impaired.
There is aris kof an accident.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions. Do no tcontinu edrivin g
under any circumstances.
XSecur eth evehicl eagainst rollin gaway (Ypage 189).
XConsult aqualified specialist workshop .
XDo notadd brak efluid .This does no tcorrec tth emalfunction .
#
CheckBrakePadWear
The brak epads/linings hav ereached their wear limit.
US Aonly: th ered $ brakesystem warning lamp also lights up while
th eengin eis running.
XVisit aqualified specialist workshop .
G
Inoperative
Oneor mor emain features of th embrace system are malfunctioning .
XVisitaqualified specialist workshop .
Display messages283
On-board computer and displays
Z
Display messagesPossible causes/consequences andMSolutions
The seat belt buckleextender on th eright or lef tof th erear compart-
men tis no tin th epredefine dposition .The seat belt buckl eextender
may be jammed .
GWARNING
If th eseat belt buckl eextender is no tin th epredefine dposition ,th e
seat belt canno tprovid eth eintended level of protection .
There is an increased ris kof injury.
XMov eth eseat cushion forward s (Ypage 107) and remove th ecaus e
of th ejam .
XRepeat th eseat belt fastenin gprocedure .
The seat belt buckl eextender on th eright or lef tof th erear compart-
men tis no tin th epredefine dposition .The seat belt may be locked.
GWARNIN G
If th eseat belt buckl eextender is no tin th epredefine dposition ,th e
seat belt canno tprovid eth eintended level of protection .
There is an increased ris kof injury.
XCompletely tak eoff your seat belt .
XRepeat theseat belt fastenin gprocedure .
The seat belt buckl eextender on th eright or lef tof th erear compart-
men tis no tin th epredefine dposition .There is no tenough belt slac k
in th esystem.
GWARNIN G
If th eseat belt buckl eextender is no tin th epredefine dposition ,th e
seat belt canno tprovid eth eintended level of protection .
There is an increased ris kof injury.
XLoosen th eseat belt .
XRepeat th eseat belt fastenin gprocedure .
The seat belt buckl eextender on th eright or lef tof th erear compart-
men tis no tin th epredefine dposition .The assistanc emeasures
specified hav ebeen carrie dout .There is still amalfunction .
GWARNING
If th eseat belt buckl eextender is no tin th epredefine dposition ,th e
seat belt canno tprovid eth eintended level of protection .
There is an increased ris kof injury.
XVisit aqualified specialist workshop immediately.
286Display messages
On-board computer and displays
Display messagesPossible causes/consequences andMSolutions
FrontPassengerAir‐bag Enable dSeeOperator' sManual
The front-passenger air bag is enabled during th ejourney, eve n
though :
Rachild, asmall adult or an objec tweighing less than th esystem' s
weigh tthreshold is locate don th efront-passenger seat
or
Rth efront-passenger seat is unoccupied
The system may detec tobjects or force sapplyin gadditional weigh ton
th eseat .
GWARNIN G
The air bag may deploy unintentionally.
There is an increased ris 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 189).
XSwitchth eignition off .
XOpenth efront-passenger door .
XRemove thechild 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 weigh tand inter-
pre tth eseat occupant's weigh tas greate rthan it actually is.
XKee pth eseat unoccupied ,close th efront-passenger door and
switch on th eignition .
XObserveth ePASSENGER AI RBA Gindicator lamp sin th ecenter
console and th emultifunction display and chec kth efollowing:
Seat unoccupied and ignition switche
d on
:
Raself-diagnosis is carrie dout .The PASSENGER AI RBA GOF Fand
PASSENGER AI RBA GON indicator lamp sligh tup simultaneousl y
for approximately six seconds
Rth ePASSENGER AI RBA GOF Findicator lamp mus tthen ligh tup
and remain lit after th eself-diagnosis .If th eindicator lamp is on ,
OCS (Occupant Classification System) has disabled th efront-
passenger fron tair bag (
Ypage 54 )
Rthedisplay message sFront Passenger Airbag Enable dSee Operator'sManualor Front Passenger Airbag Dis ‐abled See Operator'sManualmus tno tappear in th emulti-
function display.
XWait for aperiod of at least 60 seconds until th enecessar ysystem
checks hav ebeen completed.
XMak esur ethat th edisplay message sdo no tappear in th emulti-
function display.
If these condition sare fulfilled ,th efront-passenger seat can be occu-
pied again .Whether th ePASSENGER AI RBA GOF For ON indicator
lamp remain slit or goe sout depend son how OCS classifies th eoccu-
pant.
If th econdition sare no tfulfilled ,th esystem is no toperating correctly.
290Display messages
On-board computer and displays
Hybrid drive system
Display messagesPossible causes/consequences andMSolutions
d
VehicleOperationalSwitchtheIgnitionOff Before Exiting
PLUG-IN HYBRID vehicles:
You are leaving the vehicle when it is in a ready-to-drive state. The
READY indicator in the multifunction display is on. A warning tone also
sounds.
If you leave the vehicle:
XSecure the vehicle against rolling away (Ypage 189).
XSwitch off the ignition and remove the SmartKey.
If you do not leave the vehicle:
XSwitch off the electrical consumers, e.g. automatic climate control,
seat heating.
Please note the following: the electrical consumers are supplied by the 12 V battery. If the vehicle is left in a ready-to-drive state for an exten-
ded period, it will switch off once the 12 V battery is almost empty. It
will then only be possible to start the vehicle using a second battery
(jump-starting).
Change the currentdrive programbeforechangingtheoperating mode.or
Exit manual drive
program M beforechangingtheoperat‐ing mode.
PLUG-IN HYBRID vehicles:
You have attempted to change the operating mode when in automatic
drive program S(Sport) or manual drive program M.
XActivate the drive programE(Economy) or E+(Economy Plus)
(Ypage 250).
XSelect the preferred operating mode HYBRID,E-MODE,E-SAVE or
CHARGE (Ypage 243).
E-MODE CurrentlyUnavailable
PLUG-IN HYBRID vehicles:
The condition of charge of the high-voltage battery has dropped to the
lower limit and the E-MODEoperating mode has been switched off.
Driving with the internal combustion engine is activated and the oper-
ating mode switches to the basic HYBRIDsetting.
XContinue driving using the internal combustion engine.
You can switch to the E-SAVEorCHARGE operating mode as
required (
Ypage 243).
If you select CHARGE, the high-voltage battery is charged.
Once the charge level display for the high-voltage battery has
increased slightly, you can switch to the E-MODEoperating mode
again.
Display messages297
On-board computer and displays
Z
Display messagesPossible causes/consequences andMSolutions
OnlyE-MODE Availa ‐ble Power Limite dRefuel Immediately
PLUG-INHYBRID vehicles:
The fuel tan khas been run dry and th ecombustion engin ehas been
switched off .
A warning tone also sounds.
The vehicl ewill be powered by electrical energ yonly. Performance is
restricted and th evehicl emay accelerate mor eslowly than normal.
XRefue lat th eneares tgas station without fail .
In th e"Total range and electric range" menu, you can display th e
approximat erange of th evehicl e (
Ypage 248).
Engine wil lnotrestar tServic erequired
You canno tstart th eengin eagain due to amalfunction .
A warning tone also sounds.
If th eengin eis running:
XVisit aqualified specialist workshop .
If you switch off th eengine:
XSecur eth evehicl eagainst rollin gaway (Ypage 189).
XNotify aqualified specialist workshop or breakdown service.
á
Towing Not Permit ‐ted See Operator'sManual
The hybrid drive system is faulty.
XHaveth evehicl etransporte don atransporte ror trailer to th enear-
est qualified specialist workshop .
Û
MalfunctionServiceRequired
The hybrid drive system is faulty.
XVisitaqualified specialist workshop .
Û
Malfunction
The hybrid drive system is faulty.
XHaveth evehicl etowed away by aprofessional recovery compan yto
th eneares tqualified specialist workshop .
d
Malfunction
The hybrid drive system is faulty.
The ECO start/stopfunction may be malfunctioning .
The drive powe ris restricted.
XVisit aqualified specialist workshop .
ï
ChargerCable Con ‐nected
PLUG-INHYBRID vehicles:
The charging cable connecto ris connecte dto th evehicl esocket.
You canno tdrive off as lon gas th echarging cable connecto ris still
connected.
Befor eyou drive off :
XRemove thecharging cable connecto rfrom th evehicl esocke t
(Ypage 185).
298Display messages
On-board computer and displays