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Lighting117Battery 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 139 of 261

Driving and operating137Indication
An Autostop is indicated by control
indicator D.
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 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 temperatureis not too high, e.g. after driving
with high engine load.
● The ambient temperature is not too low.
● 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.
Note
The Autostop may be inhibited for
several hours after a battery
replacement or reconnection.
Certain settings of the climate control
system may inhibit an Autostop. See
Climate control chapter for more
details 3 119.
If an autostop is temporarily not
available, D flashes green 3 93.
Immediately after driving at a higher
speed an Autostop may be inhibited.
New vehicle running-in 3 131.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.
Page 256 of 261

254IndexAAccessories and vehicle modifications .......................... 186
Active emergency braking ....94, 157
Adaptive forward lighting ...........111
AdBlue .................................. 92, 140
Adjustable air vents ...................127
Advanced parking assist ............163
Airbag and belt tensioners ...........89
Airbag deactivation ................56, 89
Airbag label................................... 51 Airbag system .............................. 51
Air conditioning regular operation ................................ 129
Air conditioning system .............. 119
Air intake .................................... 128
Air vents...................................... 127
Antilock brake system ................ 147
Antilock brake system (ABS) .......91
Anti-theft alarm system ................32
Anti-theft locking system .............. 31
Appearance care ........................223
Armrest ................................... 46, 47
Ashtrays ....................................... 79 Automatic anti-dazzle ..................36
Automatic light control ...............110
Automatic locking ........................28
Automatic transmission .............143
Autostop ............................... 93, 136
Auxiliary heater ........................... 126B
Battery discharge protection ......117
Battery voltage ........................... 101 Belts.............................................. 48
BlueInjection ............................... 140
Bonnet ....................................... 188
Brake and clutch fluid .................228
Brake and clutch system .............90
Brake assist ............................... 148
Brake fluid .................................. 191
Brakes ............................... 147, 191
Breakdown.................................. 221
Bulb replacement ....................... 193
C Capacities .................................. 240
Catalytic converter .....................140
Central locking system ................24
Centre console lighting ..............116
Centre console storage ...............64
Changing tyre and wheel size ...210
Charging system .......................... 89
Child locks ................................... 29
Child restraint installation locations ................................... 60
Child restraints.............................. 57
Child restraint systems ................57
Cigarette lighter ........................... 79
Climate control ............................. 16
Climate control systems .............118