Driving and Driving Safety
169
Auto Start Stop Function
The engine stops automatically when the vehicle is
stopped, e.g. at traffic lights or in a traffic jam.
The Auto Start Stop function thus helps to
save fuel.
The ignition stays on even when the engine
switches off automatically. All safety functions
are still available.
Stopping the engine
The Auto Start Stop function stops the engine
as soon as the vehicle stops moving.
1. Use the footbrake to hold the vehicle in place.
2. Keep the footbrake pressed.
or
Move PDK selector lever to position
P
.
Preconditions for stopping the engine
– Engine compartment lid closed.
– Driver detected: driver’s seat belt fastened and
driver’s door closed.
– PDK selector lever in position
D
,
N
or
P
or
transmission range
1
or
2
selected manually.
– Engine, transmission and battery are at
operating temperature.
– Vehicle was driven at a speed of more than
approx. 1 mph (2 km/h) for at least
1.5 seconds since the engine last stopped
automatically.
Starting the engine
The Auto Start Stop function starts the engine:
f
In PDK selector-lever position
D
,
N
or manually
selected transmission range
1
or
2
:
Release the footbrake.
or
Press the accelerator.
or
f
Move PDK selector lever to position
R
.
You can drive off normally.
Note
The engine will start automatically in certain
situations, e.g. if the vehicle starts rolling, if air
conditioning causes reduced comfort, or if the
brake booster vacuum is reduced.
Starting the engine manually after leaving
the vehicle
If the driver’s seat belt is unbuckled or the driver’s
door is opened after the engine was stopped
automatically, the engine will
not
start
automatically.
Furthermore, if the brake is released, the engine
has to be started manually.
The message “Please start engine manually”
will appear on the multi-function display in the
instrument panel.
f
Please see the chapter “OVERVIEW OF
WARNING MESSAGES” on page 152.
Exceptions for the Auto Start Stop
function
The Auto Start Stop function is
not
available in the
following situations, for example:
– When Sport mode is activated.
– When PSM is off.
– In Maneuvering mode.
– When AC MAX mode is activated.
– When the “Windshield defrost” function is
active.
– While adjusting the chassis level.
– When the rear fog light is on.
The Auto Start Stop function is available
with
limited functionality
in the following situations,
for example:
– If the air conditioning or passenger
compartment heating is operated at a high
setting or if the defrost function is run for long
time periods.
– If the battery charging condition is low.
– On upward or downward slopes.
– During internal vehicle test procedures,
e.g. automatic engine checks.
Note
If one of these situations arises after the engine
has stopped automatically, the engine can be
restarted automatically.
