Page 283 of 489

Automatic engine switch-off
The internal combustion engine is switched
off automatically if:
R the driver removes his foot from the accel-
erator pedal and a speed of 160 km/h is
not exceeded (Y page 280)
R the combustion engine and the transmis-
sion have reached operating temperature
R the driver's seat belt is fastened and the
driver's door is closed
R the driver only slightly depresses the accel-
erator pedal in order to, for example, main- tain the current speed for a limited distance
R the bonnet is closed and engaged properly
R the high-voltage battery is charged suffi-
ciently
R there are no faults in the hybrid system
The internal combustion engine will not be
switched off automatically, if:
R the self-diagnosis function of the engine
control unit is still active
R the climate control of the vehicle requires it
R the high-voltage battery is being charged
(Y page 274)
R automatic emissions tests are running
R the operating temperature of the engine,
transmission and catalytic converter has
not yet been reached
Automatic engine start
The internal combustion engine, which has
been automatically switched-off, starts auto-
matically in certain situations, when:
R the power demand from the driver via the
accelerator pedal is greater than the elec-
tric motor alone can provide
R the driver switches to drive program Sor S
+
R the driver has activated manual gearshift-
ing R
the charge level of the high-voltage battery
has reached the lower limit
R the settings of the automatic climate con-
trol require it, e.g. at external temperatures
above 30 †
Overrun mode
This operating mode is available in the speed
range below 160 km/h.
The combustion engine is switched off and is disconnected from the drive train.
The electric motor:
R simulates an overrun torque which is equiv-
alent to the overrun torque of the combus-
tion engine
R functions as a generator and produces the
necessary energy for the auxiliary consum- ers and charges the high-voltage battery
Extended overrun mode
Overrun mode allows you to increase the
vehicle range.
When the vehicle is in overrun operating
mode:
X Pull the right-hand steering wheel gearshift
paddle.
Energy recuperation is reduced to the min-
imal amount of energy required. The vehi-
cle rolls faster and further, e.g. on long and steep downhill gradients or while coasting
towards a set of traffic lights.
You can see the reduction in energy recuper-
ation in the electric motor CHARGE display
(Y page 272).
The "extended overrun" operating mode is
deactivated again if:
R the combustion engine starts
R you depress the brake pedal 280
Hybrid operationDriving and pa
rking
Page 348 of 489

Display messages
Possible causes/consequences and
M
MSolutions Tyre press. moni‐
Tyre press. moni‐
tor currently tor currently
unavailable unavailable Due to a source 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 restarts automatically as soon as the
cause has been rectified. Wheel sensor(s) Wheel sensor(s)
missing 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 a qualified spe-
cialist workshop. Tyre press. moni‐ Tyre press. moni‐
tor tor
inoperative
inoperative No
No
wheel sensors
wheel sensors The wheels fitted do not have suitable tyre pressure sensors. 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 a few minutes. Tyre press. moni‐ Tyre press. moni‐
tor inoperative tor inoperative The tyre pressure monitor is faulty.
X Visit a qualified specialist workshop. Vehicle
Display messages
Possible causes/consequences and
M
MSolutions To start engine,
To start engine,
shift to either P shift to either P
or N or N You have attempted to start the engine with the transmission in
position
Ror D.
X Shift the transmission to position Por N. Auxiliary battery Auxiliary battery
malfunction malfunction The auxiliary battery for the transmission is no longer being
charged.
X Visit a qualified specialist workshop. Apply brake to Apply brake to
deselect Park (P) deselect Park (P)
position position You have attempted to move the transmission selector lever to
position
D,Ror Nwithout depressing the brake pedal.
X Depress the brake pedal. Display
messages
345On-board computer and displays Z
Page 351 of 489

Display messages
Possible causes/consequences and
M
MSolutions &
Pre-entry climate Pre-entry climate
control (via key) control (via key)
available again available again
after engine start after engine start Hybrid vehicles: with the engine switched off, you have attempted
to switch on the pre-entry climate control more than twice.
X Let the engine run for ten seconds.
After running the engine, the pre-entry climate control is opera-
tional again. &
Pre-entry climate Pre-entry climate
control (via key) control (via key)
inoperative inoperative
HV
HVbat‐
bat‐
tery low
tery low Hybrid vehicles: the on-board voltage is too low.
The pre-entry climate control cannot be switched on.
X Drive for a considerable distance.
The battery charges. The pre-entry climate control is operational
again as soon as the on-board electrical system voltage is suf-
ficient. &
Function Function
available
available
again
again after
afterengine
engine
start
start Vehicles with BlueEFFICIENCY package: you have attempted to
switch on the pre-entry climate control (eHeat/eVent) more than
3 times with the engine switched off.
X Let the engine run for ten seconds.
After running the engine, the pre-entry climate control is opera- tional again. &
inoperative Bat‐ inoperative Bat‐
tery low tery low The on-board voltage is too low.
The auxiliary heating (Y
page 172) has switched itself off. The
auxiliary heating or pre-entry climate control (eHeat/eVent) can-
not be switched on.
X Drive for a considerable distance.
The battery charges. The auxiliary heating or the auxiliary cli-
mate control ("eHeat/eVent" function) is operational again as
soon as the on-board electrical system voltage is sufficient. &
inoperative inoperative
Refuel
Refuel
vehicle
vehicle There is too little fuel in the fuel tank. The auxiliary heating cannot
be switched on (Y page 172).
X Refuel at the nearest filling station. &
inoperative See inoperative See
Owner's Man. Owner's Man. The auxiliary heating is temporarily malfunctioning or faulty.
X When the vehicle is on a level surface and the engine has cooled
down, make up to four attempts to switch on the auxiliary heat- ing, waiting several minutes between each attempt
(Y page 172).
X If the auxiliary heating does not switch on, consult a qualified
specialist workshop. 348
Display
messagesOn-board computer and displays