2018 VAUXHALL ASTRA J GTC sensor

Driving and operating161Adaptive cruise control uses a radar
sensor to detect the vehicles ahead.
If no vehicle is detected in the driving
path, the adaptive cruise control will
behave like a traditional cruise
control.
For safety reasons, the system
cannot be activated before the brake
pedal has been depressed once
since switching on ignition. Activation
in first gear is not possible.
Adaptive cruise control is mainly
advised to be used on long straight
roads, e.g. highways or country roads with steady traffic. Do not use the
system if it is not advisable to
maintain a constant speed.
Control indicator A 3 91, m 3 90.9 Warning
The complete driver attention is
always required while driving with adaptive cruise control. The driver
stays fully in control of the vehicle
because the brake pedal, the
accelerator pedal and the cancel
switch have priority over any
adaptive cruise control operation.
Switching on
Press C to switch on adaptive cruise
control. The control indicator m
illuminates white.
Activation by setting the speed
Adaptive cruise control can be
activated between 31 mph and
112 mph.
Accelerate to the desired speed and
turn thumb wheel to SET/-, the
current speed is stored and
maintained. Control indicator m
illuminates green.
The adaptive cruise control symbol,
the following distance setting and set
speed are indicated in the top line of
the Driver Information Centre.
The accelerator pedal can be
released. Adaptive cruise control
remains activated while gearshifting.
Overriding set speedIt is always possible to drive faster
than the selected set speed by
depressing the accelerator pedal.
When the accelerator pedal is
released, the vehicle returns to the
desired distance if a slower vehicle is
ahead. Otherwise it returns to the
stored speed.

164Driving and operating● There is no traffic and nothingdetected on the road sides forseveral minutes. In this case,
there are no radar echoes and
the sensor may report that it is
blocked.
● The collision imminent braking system is applying the brakes.
● The radar sensor is blocked by an ice or water film.
● A fault is detected in the radar, engine or brake system.
When adaptive cruise control is
deactivated automatically, the control indicator m illuminates white and a
warning symbol is displayed as a pop-
up in the Driver Information Centre.
The stored speed is maintained.
9 Warning
When adaptive cruise control is
deactivated, the driver must take
over full brake and engine control.
Switching off
Press C to switch off adaptive cruise
control. The control indicator m
extinguishes. The stored speed is
deleted.
Switching off the ignition also
switches off adaptive cruise control
and deletes the stored speed.
Driver's attention
● Use adaptive cruise control carefully on bends or mountain
roads, as it can lose the vehicle
ahead and need time to detect it
again.
● Do not use the system on slippery roads as it can create
rapid changes in tyre traction
(wheel spinning), so that you
could lose control.
● Do not use adaptive cruise control during rain, snow or
heavy dirt, as the radar sensor
can be covered by a water film,
dust, ice or snow. This reduces or suppresses completely the
visibility. In case of sensor
blockage, clean the sensor
cover.
System limits ● The system's automatic brake force does not permit hard
braking and the braking level
may not be sufficient to avoid a
collision.

166Driving and operatingHill and trailer considerations
System performance on hills and
when towing a trailer depends on your
vehicle speed, vehicle load, traffic
conditions and the road gradient. It
may not detect a vehicle in your path
while driving on hills. On steep hills,
you may have to use the accelerator
pedal to maintain your vehicle speed. When going downhill, especially
when towing a trailer, you may have
to brake to maintain or reduce your
speed.
Note that applying the brake
deactivates the system. It is not
recommended to use adaptive cruise
control on steep hills especially when towing a trailer.
Radar unit
The radar unit is mounted behind the
radiator grille below the brand
emblem.
9 Warning
The radar unit was aligned
carefully during manufacture.
Therefore, after a frontal accident, do not use the system. The front
bumper may appear to be intact,
however the sensor behind can be
out of position and react
incorrectly. After an accident,
consult a workshop to verify and
correct the adaptive cruise control
sensor position.
Settings
Settings can be changed in the Auto
collision preparation menu in the
vehicle personalisation, 3 103.
Fault
If the adaptive cruise control does not
work due to temporary conditions
(e.g. blockage by ice) or if there is a
permanent system error, then a
message is displayed in the Driver
Information Centre.

Driving and operating167Vehicle messages 3 97.
Forward collision alert The forward collision alert can help to
avoid or reduce the harm caused by
front-end crashes.
A vehicle ahead is indicated by a
control indicator A.
If a vehicle directly ahead is
approached too quickly, a warning
chime and alert in the Driver
Information Centre is provided.
A precondition is that forward collision
alert is activated in the vehicle
personalisation menu 3 103 or that it
is not deactivated by pressing V
(depending on the system, see
following).
Depending on the vehicle's
equipment, there are two variants of
the forward collision alert available:
● Forward collision alert based on
radar system
on vehicles equipped with
adaptive cruise control 3 160.
● Forward collision alert based on
front camera system
on vehicles with traditional cruise
control or none 3 157.
Forward collision alert based on
radar system
The system uses the radar sensor
behind the radiator grille to detect a
vehicle directly ahead, in your path,
within a maximum distance of
150 metres.
Activation
Forward collision alert operates
automatically above walking speed,
provided that Auto collision
preparation setting is not deactivated
in the vehicle personalisation menu
3 103.
Selecting the alert sensitivity
The alert sensitivity can be set to
near, medium or far.

170Driving and operatingDeactivation
The system can be deactivated.
Press V repeatedly until the following
message appears in the Driver
Information Centre.
General information for both
variants of forward collision alert
9 Warning
Forward collision alert is just a
warning system and does not
apply the brakes. When
approaching a vehicle ahead too
rapidly, it may not provide you
enough time to avoid a collision.
The driver accepts full
responsibility for the appropriate
following distance based on traffic, weather and visibility conditions.
The complete attention of the
driver is always required while
driving. The driver must always be
ready to take action and apply the
brakes.
System limitations
The system is designed to warn only for vehicles, but may react also to
other metallic objects.
In the following cases, forward
collision alert may not detect a vehicle ahead or sensor performance is
limited:
● on winding roads
● when weather limits visibility, e.g.
fog, rain, or snow
● when the sensor is blocked by snow, ice, slush, mud, dirt, or
windscreen damage
Following distance
indication
The following distance indication
displays the distance to a preceding
moving vehicle. The system uses,
depending on the vehicle equipment,
either the radar behind the radiator
grille or the front camera in the
windscreen to detect the distance of
a vehicle directly ahead in your lane.
It is active at speeds above 25 mph.
When a preceding vehicle is detected
ahead, the distance is indicated in
seconds, displayed on a page in the
Driver Information Centre 3 91 . Press
MENU on the turn signal lever to
select Vehicle Information Menu
X and turn the adjuster wheel to
choose following distance indication
page.

Driving and operating171
The minimum indicated distance is
0.5 s.
If there is no vehicle ahead or the vehicle ahead is out of range, two
dashes will be displayed: -.- s.
Active Emergency Braking
Active emergency braking can help to reduce the damage from crashes with vehicles and obstacles directly
ahead, when a collision can no longer be avoided either by manual braking
or by steering. Before the active
emergency braking applies, the driver
is warned by the forward collision
alert 3 167.
The feature uses various inputs (e.g.
radar sensor, brake pressure, vehicle speed) to calculate the probability of
a frontal collision.
Active emergency braking operates automatically above walking speed,
provided that Auto collision
preparation setting is not deactivated
in the vehicle personalisation menu
3 103.
The system includes: ● brake preparation system
● emergency automatic braking
● forward looking brake assist9Warning
This system is not intended to
replace the driver responsibility of driving the vehicle and looking
ahead. Its function is limited to
supplemental use only. The driver shall continue to apply the brake
pedal as the driving situation
dictates.
Brake preparation system
When approaching a vehicle ahead
so quickly that a collision is likely, the
brake preparation system slightly
pressurises the brakes. This reduces
the response time, when a manual or automatic braking is requested.
The brake system is prepared so that braking can occur more rapidly.
Emergency automatic braking
After the brake preparation and just
before the imminent collision, this
function automatically applies limited
braking to reduce the impact speed of the collision.
Forward looking brake assist
In addition to brake preparation
system and emergency automatic
braking, the forward looking brake
assist function makes the brake assist more sensitive. In this way,
depressing the brake pedal slightly
results immediately in a strong
braking. This function helps the driver
brake quicker and stronger before the imminent collision.

172Driving and operating9Warning
Active emergency braking is not
designed to apply strong
autonomous braking or to avoid automatically a collision. It is
designed to reduce the vehicle
speed before collision. It may not
react on stopped vehicles,
pedestrians or animals. After a
sudden lane change, the system
needs a certain time to detect the
next preceding vehicle.
The complete attention of the
driver is always required while
driving. The driver shall always be ready to take action and apply the brakes and steer to avoid
collisions. The system is designed
to work with all occupants wearing their seat belts.
System limitations
The active emergency braking has
limited or no function during rain,
snow or heavy dirt, as the radar
sensor can be covered by a water
film, dust, ice or snow. In case of
sensor blockage, clean the sensor
cover.
In some seldom cases the active
emergency braking system may
provide a short automatic braking in
situations that seem to be
unnecessary, for instance due to
traffic signs in a curve or due to
vehicles in another lane. This is
acceptable operation, the vehicle
does not need service. Firmly apply
the accelerator pedal to override the
automatic braking.
Settings
Settings can be changed in the Auto
collision preparation menu in the
vehicle personalisation, 3 103.
Fault
In the event of a system service
requirement, a message is displayed
in the Driver Information Centre.
If the system does not work as it
should do, vehicle messages are
displayed in the Driver Information
Centre.
Vehicle messages 3 97.

Driving and operating173Parking assist
Rear parking assist9 Warning
The driver bears full responsibility
for the parking manoeuvre.
Always check the surrounding
area while reversing and using the rear parking assist system.
The rear parking assist makes
parking easier by measuring the
distance between the vehicle and
rear obstacles. It informs and warns
the driver by giving acoustic signals.
The system has four ultrasonic
parking sensors in the rear bumper.
Activation
When reverse gear is engaged, the
system is ready to operate
automatically.
An illuminated LED in the parking
assist button r indicates that the
system is ready to operate.
Indication
The system warns the driver with
acoustic signals against potentially
hazardous obstacles behind the
vehicle. The interval between the
sounds becomes shorter as the
vehicle gets closer to that obstacle.
When the distance is less than
approx. 30 cm, the sound is
continuous.
Additionally, the distance to obstacles may be shown in the Driver
Information Centre.Deactivation
The system automatically switches
off when reverse gear is disengaged.
To switch on the system again,
engage reverse gear.
Manual deactivation is also possible by pressing r.
When the system is deactivated, the
LED in the button extinguishes.
Additionally, Park Assist Off pops-up
in the Driver Information Centre when
the system is deactivated manually.