brake VOLVO XC90 TWIN ENGINE 2019 Service Manual

DRIVER SUPPORT
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317
WARNING
The Pilot Assist function is supplementary
driver support intended to facilitate driv-
ing and help make it safer – it cannot
handle all situations in all traffic, weather
and road conditions.
The driver is advised to read all sections
in the Owner's Manual about this function
to learn of its limitations, which the driver
must be aware of before using the func-
tion (see the link list at the end of this
article).
Pilot Assist should only be used if there
are clear lane lines painted on each side
of the lane. All other use will increase the
risk of contact with nearby obstacles that
cannot be detected by the functions.
Pilot Assist is not a substitute for the driv-
er's attention and judgment. The driver is
always responsible for ensuring the vehi-
cle is driven in a safe manner, at the
proper position within the lane, at the
appropriate speed, with an appropriate
distance to other vehicles, and in accord-
ance with current traffic rules and regula-
tions.NOTE Depending on market, this function may be
either Standard or Optional.
Pilot Assist regulates speed by accelerating and
braking. It is normal for the brakes to emit a slight
sound when they are being used to adjust speed.
Pilot Assist attempts to smoothly regulate speed.
The driver must apply the brakes in situations
requiring immediate braking. For example, when
there are great differences in speed between
vehicles or if the vehicle ahead brakes suddenly.
Due to limitations in the camera and radar sen-
sor, braking may occur unexpectedly or not at all.
Pilot Assist is designed to follow a vehicle ahead
in the same lane and maintain a time interval to
that vehicle set by the driver. If the radar sensor
does not detect a vehicle ahead, it will instead
maintain the speed set by the driver. This will also
happen if the speed of the vehicle ahead
exceeds the set speed for your vehicle.
Pilot Assist can follow another vehicle at
speeds from a standstill up to 200 km/h
(125 mph).
Pilot Assist can provide steering assistance
from near-stationary speeds up to 140 km/h
(87 mph).WARNING
Pilot Assist is not a collision avoidance
system. The driver must intervene if the
system fails to detect a vehicle ahead.
Pilot Assist does not brake for people,
animals, objects, small vehicles (e.g.
cycles and motorcycles), low trailers as
well as oncoming, slow or stationary vehi-
cles.
Do not use Pilot Assist in demanding sit-
uations, such as in city traffic, at intersec-
tions, on slippery surfaces, with a lot of
water or slush on the road, in heavy rain/
snow, in poor visibility, on winding roads,
on highway on- or off-ramps, or with a
trailer connected to the vehicle.
CAUTION Maintenance of the integrated components in
Pilot Assist may only be performed by a work-
shop – an authorized Volvo workshop is rec-
ommended.
In curves and forks in the roadPilot Assist is designed to interact with the driver.
The driver should never wait for steering assis-
tance from Pilot Assist, but instead should always
be ready to increase his or her own steering
efforts, particularly in curves.

DRIVER SUPPORT
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* Option/accessory. 319
Instrument panelSpeed indicators
57
. Set speed
Speed of the vehicle ahead
The current speed of your vehicle
See "Pilot Assist symbols and messages" for
examples of different combinations of symbols
depending on the traffic situation.
Related information
Pilot Assist and collision warning (p. 319)
Head-up display for Pilot Assist during colli-
sion risks (p. 320)
Activating and starting Pilot Assist (p. 320)
Managing Pilot Assist speed (p. 322)
Setting a time interval for Pilot Assist
(p. 323)
Deactivating/reactivating Pilot Assist
(p. 324)
Passing assistance with Pilot Assist (p. 326)
Starting passing assistance with Pilot Assist
(p. 327)
Passing assistance with Pilot Assist limita-
tions (p. 327)
Switching target vehicles with Pilot Assist
(p. 327)
Auto-hold braking with Pilot Assist (p. 328)
Pilot Assist limitations (p. 329)
Pilot Assist* symbols and messages (p. 330) Pilot Assist and collision warning
Pilot Assist can alert the driver if the distance to
the vehicle ahead suddenly decreases to an
unsafe distance. Collision warning light on the windshield
58
. Audio-visual collision warning
Camera/radar sensor distance monitoring
Pilot Assist uses approx. 40% of the vehicle's
braking capacity. If a situation requires more
braking force than Pilot Assist can provide, and if
the driver does not apply the brakes, a warning
light and audible warning signal will be activated
to alert the driver that immediate action is
required. 57
Note: This illustration is general and details may vary depending on mod\
el.
58 The illustration is generic - details may vary according to vehicle mode\
l.

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* Option/accessory.
320
NOTE Visual warnings on the windshield may be dif-
ficult to notice in cases of strong sunlight,
reflections, extreme light contrasts, or if the
driver is wearing sunglasses or is not looking
straight ahead.
WARNING
Pilot Assist only issues a warning for vehicles
detected by its camera and radar unit – thus,
a warning may come after a delay or not at all.

Never wait for a warning. Apply the
brakes when necessary!
Related information
Pilot Assist (p. 316) Head-up display for Pilot Assist
during collision risks
In vehicles equipped with a head-up display*, a
flashing warning symbol will be displayed on the
windshield. Collision warning symbol on the windshield
59
.
NOTE Visual warnings on the windshield may be dif-
ficult to notice in cases of strong sunlight,
reflections, extreme light contrasts, or if the
driver is wearing sunglasses or is not looking
straight ahead.
Related information

Pilot Assist (p. 316)
Head-up display* (p. 142) Activating and starting Pilot Assist
Pilot Assist must first be activated and then
started before it can help regulate speed and
distance and provide steering assistance.
Note: This illustration is general and details may vary
depending on model.
To start Pilot Assist:

The driver's seat belt must be buckled and
the driver's door must be closed.
There must be a vehicle ahead (target vehi-
cle) within a reasonable distance or your
vehicle's current speed must be at least
15 km/h (9 mph). 59
Note: This illustration is general and details may vary depending on mod\
el.

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325
Standby mode due to action by the driver
Pilot Assist will be temporarily deactivated and
put in standby mode if: the brakes are applied.
the gear selector is moved to N
a turn signal is used for more than 1 minute.
the vehicle is driven faster than the set
speed for more than 1 minute
Temporarily increasing speed using the accelera-
tor pedal, e.g. when passing another vehicle, will
not affect the setting. The vehicle will return to
the set speed when the accelerator pedal is
released.
When the turn signals are used, Pilot Assist's
steering assistance will be temporarily deacti-
vated. When the turn signal is switched off, steer-
ing assistance will be automatically reactivated if
the traffic lane's side markings can still be
detected.
Automatic standby mode
Pilot Assist is dependent on other systems, such
as Electronic Stability Control (ESC 61
). If any of
these other systems stops working, Pilot Assist
will automatically switch off.
WARNING With automatic standby mode, the driver is
warned by an acoustic signal and a message
on the instrument panel.

The driver must then regulate vehicle
speed, apply the brakes if necessary, and
maintain a safe distance to other vehicles.
Adaptive Cruise Control may go into standby
mode if, e.g.:
the driver opens the door.
the brake temperature is high.
the driver's hands are not on the steering
wheel.
the parking brake is applied.
the engine speed (rpm) is too low/high.
the driver unbuckles the seat belt.
one or more of the wheels lose traction.
the camera/radar sensor is covered by snow
or heavy rain (the camera lens/radar waves
are blocked)
your vehicle's speed goes below 5 km/h
(3 mph) and Pilot Assist cannot determine if
the vehicle ahead is stationary or if it is
another object, e.g. a speed bump.
your vehicle's speed goes under 5 km/h
(3 mph) and the vehicle ahead turns so that
Pilot Assist no longer has a vehicle to follow.
Reactivating Pilot Assist from standby
mode Note: This illustration is general and details may vary
depending on model.
To reactivate Pilot Assist:
–
Press the button on the steering wheel
(1).
>

Speed will be set to the most recently
stored speed. 61
Electronic Stability Control

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327
Starting passing assistance with
Pilot Assist
Several conditions must be met for passing
assistance to be possible.
In order to activate passing assistance:
your vehicle must be following a vehicle
ahead (target vehicle)
your vehicle's current speed must be
at least 70 km/h (43 mph)
the set speed for Pilot Assist must be high
enough to safely pass another vehicle.
Starting parking assistanceTo start passing assistance:
–
Turn on the left turn signal.
>

Passing assistance will start.
Related information
Pilot Assist (p. 316)
Passing assistance with Pilot Assist (p. 326) Passing assistance with Pilot Assist
limitations
Passing assistance functionality may be reduced
in certain situations.
WARNING The driver should be aware that if conditions
suddenly change when using Parking Assis-
tance, the function may implement an unde-
sired acceleration in certain conditions.
Some situations should be avoided, e.g. if:

the vehicle is approaching an exit in the
same direction as passing would normally
occur
the vehicle ahead slows before your vehi-
cle has had time to switch to the passing
lane
traffic in the passing lane slows down
a vehicle for right-hand traffic is driven in
a country with left-hand traffic (or vice
versa).
Situations of this type can be avoided by tempo-
rarily putting Pilot Assist in standby mode.
Related information
Pilot Assist (p. 316)
Passing assistance with Pilot Assist (p. 326) Switching target vehicles with Pilot
Assist
At certain speeds, models with automatic trans-
missions and

Pilot Assist can switch target vehi-
cles.
Switching target vehicles If the target vehicle ahead turns suddenly, there may be
stationary traffic ahead.
When Pilot Assist is actively following another
vehicle at speeds under 30 km/h (20 mph) and
switches targets from a moving vehicle to a sta-
tionary vehicle,

Pilot Assist will brake for the sta-
tionary vehicle.

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328
WARNING
When Pilot Assist follows another vehicle at
speeds over approx. 30 km/h (20 mph) and
changes target vehicle – from a moving vehi-
cle to a stationary one – Pilot Assist will
ignore the stationary vehicle and instead
accelerate to the stored speed.
The driver must then intervene and apply
the brakes.
Automatic standby mode when switching
targets
Pilot Assist disengages and goes into standby
mode if:
your vehicle's speed goes below 5 km/h
(3 mph) and Pilot Assist cannot determine if
the target object is a stationary vehicle or
another object, e.g. a speed bump.
your vehicle's speed goes under 5 km/h
(3 mph) and the vehicle ahead turns so that
Pilot Assist no longer has a vehicle to follow.
Related information
Pilot Assist (p. 316) Auto-hold braking with Pilot Assist
Pilot Assist has a special braking function in
slow traffic and at a standstill.
Braking function in slow traffic and at a
standstill
In slow-moving, stop-and-go traffic or when stop-
ped at a traffic light, driving will resume automati-
cally if the vehicle is stopped for less than
approx. 3 seconds. If it takes more than 3 sec-
onds for the vehicle ahead to begin moving again,
Pilot Assist will go into standby mode and the
Auto-hold brake function will activate.
– Pilot Assist can be reactivated by:
Pressing the button on the steering
wheel keypad.
Pressing the accelerator pedal.
>

Pilot Assist will resume following the vehi-
cle ahead if it begins to move within
approx. 6 seconds.
NOTE Pilot Assist can keep the vehicle stationary
for no more than 5 minutes – after that time
the parking brake is applied and the function
is deactivated.
The parking brake must be released before
Pilot Assist can be reactivated.
Deactivation of the Auto-hold brake function
In certain situations, Auto-hold will be deactivated
when the vehicle is at a standstill and Pilot Assist
will go into standby mode. This means that the
brakes will be released and the vehicle could
begin to roll. The driver must actively apply the
brakes to keep the vehicle stationary.
This can occur if:
the driver depresses the brake pedal
the parking brake is applied
the gear selector is moved to the P, N or R
positions
the driver puts Pilot Assist in standby mode.
Auto Activate Parking BrakeIn certain situations, the parking brake will be
applied to keep the vehicle at a standstill.
This occurs if Pilot Assist is keeping the vehicle
stationary using the brakes and:
the driver opens the door or unbuckles
his/her seat belt
Pilot Assist has kept the vehicle at a stand-
still for more than approx. 5 minutes
the brakes overheat
the driver switches off the engine manually.
Related information
Pilot Assist (p. 316)

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* Option/accessory.
330
Steep roads and/or heavy loadsPilot Assist is primarily intended to be driven on
flat roads. The function may not be able to main-
tain the correct time interval to the vehicle ahead
when driving down steep hills. The driver should
be extra attentive and prepared to apply the
brakes.
Do not use Pilot Assist if the vehicle is carry-
ing a heavy load or towing a trailer.
NOTE Pilot Assist cannot be activated if a trailer,
bike carrier or similar is connected to the
vehicle electrical system.
Other limitations

The
Off Road drive mode cannot be
selected when Pilot Assist is activated.
NOTE The function uses the vehicle's combined
camera and radar unit, which has certain gen-
eral limitations; see sections "Camera limita-
tions" and "Radar sensor limitations".
Related information

Pilot Assist (p. 316)
Speed-dependent steering wheel resistance
(p. 278)
Camera limitations (p. 338)
Radar sensor limitations (p. 333) Pilot Assist* symbols and messages
A number of symbols and messages relating to
Pilot Assist may be displayed in the instrument
panel and/or the head-up display*.

DRIVER SUPPORT
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341
Recommended maintenance for the
camera/radar sensor
In order for the camera/radar sensor to function
properly, the area of the windshield in front of
the unit must be kept free of dirt, ice, snow, etc.
and should be washed regularly with water and
car washing detergent.
NOTE Dirt, ice and snow covering the camera and
radar unit reduce their function and can make
measurement impossible.
It could cause functions to be reduced, deac-
tivated completely or produce an incorrect
function response.
Related information

Camera (p. 337) City Safety™
City Safety can alert the driver with light, sound
and pulsations in the brake pedal to help the
driver detect pedestrians, cyclists, large animals
and vehicles that appear suddenly – the vehicle
will then attempt to automatically brake if the
driver does not act within a reasonable amount
of time. Location of the camera and radar sensor
70
.
City Safety can help prevent a collision or lower
the vehicle's speed at the point of impact.
City Safety is an aid intended to assist the driver
if a collision with a pedestrian, large animal,
cyclist or vehicle is imminent.
City Safety can help the driver avoid a collision
when e.g. driving in stop-and-go traffic, when changes in the traffic ahead and driver distraction
could lead to an incident.
The function assists the driver by automatically
applying the brakes if there is an imminent risk of
a collision and the driver does not react in time by
braking and/or steering away.
City Safety activates a brief, forceful braking in an
attempt to stop your vehicle immediately behind
the vehicle or object ahead.
City Safety is activated in situations in which the
driver should have applied the brakes much ear-
lier, which means that the system will not be able
to assist the driver in all situations.
City Safety is designed to be activated as late as
possible to help avoid unnecessary intervention.
Normally, the occupants of the vehicle will not be
aware of City Safety except when the system
intervenes when a collision is imminent.
70
Note: This illustration is general and details may vary depending on mod\
el.

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342
WARNING

The City Safety function is supplementary
driver support intended to help improve
driving safety – it cannot handle all situa-
tions in all traffic, weather and road condi-
tions.
The City Safety auto-brake function can
prevent a collision or reduce collision
speed, but to ensure full brake perform-
ance the driver should always depress the
brake pedal – even when the car auto-
brakes.
The warning and steering assistance are
only activated if there is a high risk of col-
lision – you must therefore never wait for
the collision warning or City Safety to
intervene.
Warnings and brake interventions for
pedestrians and cyclists are disengaged
at vehicle speeds over 80 km/h
(50 mph).
City Safety does not activate auto-braking
intervention during heavy acceleration.
City Safety is not a substitute for the driv-
er's attention and judgment. The driver is
always responsible for ensuring the vehi-
cle is driven in a safe manner, at the
appropriate speed, with an appropriate
distance to other vehicles, and in accord-
ance with current traffic rules and regula-
tions.
The driver is advised to read all sections
in the Owner's Manual that relate to City
Safety to learn about factors such as its
limitations and what the driver should be
aware of before using the system (see
the list of links for all subsections).
Related information
City Safety parameters and sub-functions
(p. 342)
Setting a warning distance for City Safety
(p. 344)
Detecting obstacles with City Safety (p. 345)
City Safety in crossing traffic (p. 347)
Limitations of City Safety in crossing traffic
(p. 348)
City Safety and delayed evasive maneuvers
(p. 349)
City Safety braking for oncoming vehicles
(p. 350)
City Safety limitations (p. 351)
City Safety messages (p. 353) City Safety parameters and sub-
functions
City Safety can help avoid a collision with a vehi-
cle, cyclist or large animal ahead by reducing the
vehicle's speed using its automatic braking func-
tion.
If the difference in speed is greater than the
speeds specified below, the City Safety auto-
brake function cannot prevent a collision, but it
can help mitigate its effects.
Vehicles
City Safety can help prevent a collision with a
vehicle ahead by reducing your vehicle's speed
by up to 60 km/h (37 mph).
Cyclists
City Safety can help prevent a collision with a
cyclist ahead by reducing your vehicle's speed by
up to 50 km/h (30 mph).
Pedestrians
City Safety can help prevent a collision with a
pedestrian ahead by reducing your vehicle's
speed by up to 45 km/h (28 mph).

DRIVER SUPPORT
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* Option/accessory. 343
Large animals
If there is a risk of colliding with a large animal,
City Safety can help reduce your vehicle's speed
by up to 15 km/h (9 mph).
The braking function for large animals is primarily
intended to mitigate the force of a collision at
higher speeds. Braking is most effective at
speeds above 70 km/h (43 mph) and less effec-
tive at lower speeds.
City Safety sub-functionsFunction overview
71
. Audio-visual collision warning
Camera/radar sensor distance monitoring City Safety carries out three steps in the follow-
ing order:
1.

Collision warning
2. Brake assistance
3. Auto-brake
Descriptions of what happens in these three
steps are provided below.
1 - Collision warning
The driver is first alerted to the risk of an immi-
nent collision.
In vehicles equipped with a head-up display*, a
flashing warning symbol will be displayed on the
windshield. Collision warning symbol on the windshield
72
.
NOTE Visual warnings on the windshield may be dif-
ficult to notice in cases of strong sunlight,
reflections, extreme light contrasts, or if the
driver is wearing sunglasses or is not looking
straight ahead.
City Safety can detect pedestrians, cyclists or
vehicles that are stationary, are moving in the
same direction as your vehicle and are ahead of
your vehicle. City Safety can also detect pedes-
trians, cyclists or large animals that are crossing
the road in front of your vehicle.
If there is a risk of a collision with a pedestrian,
large animal, cyclist or another vehicle, or with a
vehicle described in the section "City Safety in
crossing traffic", the driver will be alerted with
light, sound and pulsations in the brake pedal. At
lower speeds, during hard braking or if the accel-
erator pedal is pressed, the brake pedal pulsation
warning will not be given. The intensity of the
brake pedal pulsations varies according to the
vehicle's speed.
71
Note: This illustration is general and details may vary depending on mod\
el.
72 Note: This illustration is general and details may vary depending on mod\
el.