Page 121 of 257
Lighting119Battery discharge protection
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 window and 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.
Switching off electric lights
To prevent discharge of the vehicle
battery when the ignition is switched
off, some interior lights are switched
off automatically after some time.
Page 141 of 257

Driving and operating139● The engine exhaust temperatureis not too high, e.g. after driving
with high engine load.
● The ambient temperature is sufficient.
● The climate control system allows an Autostop.
● The brake vacuum is sufficient.
● The self-cleaning function of the diesel particle filter is not active.
Otherwise an Autostop will be
inhibited.
Certain settings of the climate control
system may inhibit an Autostop. See
Climate control chapter for more
details 3 121.
If an autostop is temporarily not
available, D flashes green 3 95.
Immediately after driving at a higher
speed an Autostop may be inhibited.
New vehicle running-in 3 133.
Vehicle battery discharge protection
To ensure reliable engine restarts, several vehicle battery discharge
protection features are implemented
as part of the stop-start system.Power saving measures
During an Autostop, several electrical
features such as auxiliary electric
heater or rear window heating are
disabled or switched to a power
saving mode. The fan speed of the
climate control system is reduced to save power.
Restart of the engine by the driver
Vehicles with manual transmissionConventional restart
All engines have conventional restart.
Depress the clutch pedal without
depressing the brake pedal to restart
the engine.
On engines with late restart a
conventional restart is only possible
without depressed brake pedal.
Restart of the engine by the stop-
start system
The selector lever must be in neutral to enable an automatic restart.
If one of the following conditions
occurs during an Autostop, the
engine will be restarted automatically
by the stop-start system:
● The stop-start system is manually deactivated.
● The driver's seat belt is unfastened or the driver's door is
opened.
● The engine temperature is too low.
● The charging level of the vehicle battery is below a defined level.
● The brake vacuum is not sufficient.
● The climate control system requests an engine start.
● The air conditioning is manually switched on.
If an electrical accessory, e.g. a
portable CD player, is connected to
the power outlet, a brief power drop
during the restart might be noticeable.
Page 252 of 257

250IndexAAccessories and vehicle modifications .......................... 185
Active emergency braking ..........157
Adaptive forward lighting ...........113
AdBlue .................................. 94, 142
Adjustable air vents ...................129
Advanced parking assist ............164
Airbag and belt tensioners ...........91
Airbag deactivation ................57, 91
Airbag label................................... 52 Airbag system .............................. 52
Air conditioning regular operation ................................ 131
Air conditioning system .............. 121
Air intake .................................... 130
Air vents...................................... 129
Antilock brake system ................ 149
Antilock brake system (ABS) .......92
Anti-theft alarm system ................33
Anti-theft locking system .............. 32
Appearance care ........................221
Armrest ................................... 47, 48
Ashtrays ....................................... 81
Automatic anti-dazzle ..................37
Automatic light control ...............112
Automatic locking ........................29
Automatic transmission .............145
Autostop ............................... 95, 138
Auxiliary heater ........................... 128B
Battery discharge protection ......119
Battery voltage ........................... 102 Belts.............................................. 49
BlueInjection ............................... 142
Bonnet ....................................... 187
Brake and clutch fluid .................226
Brake and clutch system .............92
Brake assist ............................... 150
Brake fluid .................................. 190
Brakes ............................... 149, 190
Breakdown.................................. 219
Bulb replacement ....................... 192
C
Capacities .................................. 238
Catalytic converter .....................141
Central locking system ................25
Centre console lighting ..............118
Centre console storage ...............66
Changing tyre and wheel size ...209
Charging system .......................... 91
Child locks ................................... 30
Child restraint installation locations ................................... 61
Child restraints.............................. 58
Child restraint systems ................58
Cigarette lighter ........................... 81
Climate control ............................. 16
Climate control systems .............120