Page 160 of 315

158Driving and operatingIndication
An Autostop is indicated by the
needle at the AUTOSTOP position in
the tachometer.
After restarting, the idle speed is
indicated.
During an Autostop, the heating and
brake performance will be
maintained.
Conditions for an Autostop
The stop-start system checks if each
of the following conditions is fulfilled:
● The stop-start system is not manually deactivated.
● The bonnet is fully closed.
● The driver's door is closed or the driver's seat belt is fastened.
● The vehicle battery is sufficiently charged and in good condition.
● The engine is warmed up.
● The engine coolant temperature is not too high.
● The engine exhaust temperature is not too high, e.g. after driving
with high engine load.
● The ambient temperature is above -5 °C.
● The climate control system allows an Autostop.
● The brake vacuum is sufficient.
● Between the last restart and a new Autostop must be about10 seconds.
● The self-cleaning function of the exhaust filter is not active.
● The vehicle was driven at least at
walking speed since the last
Autostop.
Otherwise an Autostop will be
inhibited.The stop-start system will be
deactivated on inclines of 12% or
more.
Certain settings of the climate control
system may inhibit an Autostop. See
Climate control chapter for more
details 3 140.
Immediately after motorway driving,
an Autostop may be inhibited.
New vehicle running-in 3 152.
Vehicle battery discharge protection
To ensure reliable engine restarts,
several battery discharge protection
features are implemented as part of
the stop-start system.
Power saving measures
During an Autostop, several electrical
features e.g. auxiliary electric heater
or heated rear window are disabled or switched to a power saving mode.
The fan speed of the climate control
system is reduced to save power.
Page 238 of 315

236Vehicle careReplacing the vehicle batteryNote
Any deviation from the instructions
given in this section may lead to
temporary deactivation or
disturbance of the stop-start system.
When the vehicle battery is being
replaced, please ensure that there
are no open ventilation holes in the
vicinity of the positive terminal. If a
ventilation hole is open in this area, it
must be closed off with a dummy cap, and the ventilation in the vicinity of the negative terminal must be opened.
Ensure that the battery is always
replaced by the same type of battery.
We recommend that you have the
vehicle battery replaced by a
workshop.
Stop-start system 3 157.Charging the vehicle battery9 Warning
On vehicles with stop-start
system, ensure that the charging potential does not exceed 14.6 V
when using a battery charger.
Otherwise the vehicle battery may be damaged.
Jump starting 3 269.
Discharge protection Battery voltage
When the vehicle battery voltage is
running low, a warning message will
appear in the Driver Information
Centre.
1. Switch off any electrical consumers which are not requiredfor a safe ride, e.g. seat heating,
heated rear window or other main consumers.
2. Charge the vehicle battery by driving continuously for a while or
by using a charging device.
The warning message will disappear
after the engine has been started
twice without a voltage drop.
If the vehicle battery cannot be
recharged, have the cause of the fault
remedied by a workshop.
Vehicle battery state of charge
function
The function guarantees longest vehicle battery life via a generator
with controllable power output and
optimised power distribution.
To prevent discharge of the vehicle
battery when driving, the following
systems are reduced automatically in two stages and finally switched off:
● auxiliary heater
● heated rear and front window
● heated steering wheel
● heated mirrors
● heated seats
● fan
In the second stage, a message
which confirms the activation of the
vehicle battery discharge protection
will be displayed in the Driver
Information Centre.
Page 310 of 315

308IndexAAccessories and vehicle modifications .......................... 229
Active bonnet ................................ 72
Active emergency braking ..........194
Adaptive cruise control .......110, 181
AdBlue ................................ 109, 162
Adjustable air vents ...................149
Airbag and belt tensioners .........106
Airbag deactivation ..............64, 106
Airbag label................................... 59
Airbag system .............................. 59
Air conditioning regular operation ................................ 150
Air conditioning system .............. 140
Air intake .................................... 150
Air vents...................................... 149
All-wheel drive ........................... 170
Antilock brake system ................ 170
Antilock brake system (ABS) .....107
Anti-theft alarm system ................35
Anti-theft locking system .............. 35
Appearance care ........................273
Armrest ................................... 54, 56
Armrest storage ........................... 75
Ashtrays ....................................... 96 Automatic anti-dazzle ..................41
Automatic dimming ......................40
Automatic light control ...............130
Automatic locking ........................28Automatic transmission .............165
Autostop ..................................... 157
Auxiliary heater ........................... 149
B Baselevel display ........................111
Battery discharge protection ......139
Belts.............................................. 57 BlueInjection ............................... 162
Bonnet ....................................... 231
Brake and clutch fluid .................279
Brake and clutch system ...........107
Brake assist ............................... 173
Brake fluid .................................. 234
Brakes ............................... 170, 234
Breakdown.................................. 271
Bulb replacement ....................... 238
C Capacities .................................. 292
Cargo management system ........81
Catalytic converter .....................162
Central locking system ................26
Centre console lighting ..............138
Centre console storage ...............75
Changing tyre and wheel size ...259
Charging system ........................ 106
Child locks ................................... 29
Child restraint installation locations ................................... 68
Child restraints.............................. 65