Volvo XC90 Excellence (2018 year). Instruction

STARTING AND DRIVING

428

OFF ROAD

•

Maximise the car's traction when driving in
difficult terrain and on poor roads.

The drive mode provides high ground clearance

steering is light, all-wheel drive and the function
for low speed control with hill descent control
(Hill Descent Control) are activated.

The drive mode is only available at low speeds, up
to 40 km/h (25 mph). If this speed is exceeded,
Off road mode is cancelled and the

AWD

drive

mode is activated instead.

To be able to drive all four wheels, the internal
combustion engine and electric motor run contin-
ually, which results in increased fuel consump-
tion.

In the Off road mode the driver display has a
compass between the speedometer and tachom-
eter. The speedometer shows the range for
speed limitation.
The drive mode is optimised for maximum con-
trollability at low speeds in poor road conditions
or difficult terrain. It raises the chassis

, reduces

the driveline's throttle response and locks the car
in all-wheel drive. The Hill Descent Control func-
tion facilitates controlled driving on steep
descents.

NOTE

The driving mode is not designed to be used
on public roads.

NOTE

If the car is switched off in OFF ROAD mode,
and therefore has high ground clearance, the
car is lowered next time it is started.

IMPORTANT

The OFF ROAD drive mode must not be used
while driving with a trailer without trailer con-
nector. Otherwise, there is a risk of damage to
the air bellows.

AWD

•

Improve the car's roadholding and traction
with enhanced all-wheel drive.

The drive mode locks the car in all-wheel drive.
An optimal distribution between the front and
rear axle torque gives the best traction, stability
and roadholding, for example on slippery roads,
when driving with a heavy trailer, or when towing.
AWD drive mode is always available regardless of
the battery's state of charge.

Both the internal combustion engine and electric
motor are engaged in order to drive all four

wheels, which results in increased fuel consump-
tion.

In the car's other drive modes, the car automati-
cally adapts the need for all-wheel drive to the
road surface, and can engage the electric motor
or start the internal combustion engine when
necessary.

POWER

•

Power mode means that the car has sportier
characteristics and faster response to accel-
erating.

The drive mode maximises the combined power
from the internal combustion engine and electric
motor by means of the car being driven by both
front and rear wheels. The gear changes become
faster and more distinct, and the gearbox prioriti-
ses a gear with greater traction. Steering
response is faster, shock absorption is harder
and a lower ground clearance

means that the

body follows the roadway in order to reduce roll
during cornering.

Both the internal combustion engine and electric
motor are engaged in order to drive all four
wheels, which results in increased fuel consump-
tion.

Applies with air suspension.

STARTING AND DRIVING

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429

The drive mode is optimised for maximum per-
formance and response during acceleration. It
changes the internal combustion engine's accel-
erator pedal response, gear shift pattern and
boost pressure system. Chassis settings, steering
and brake response are also optimised. Power
drive mode is always available regardless of the
battery's state of charge.

INDIVIDUAL

•

Adapting a drive mode according to individ-
ual preferences.

Select a drive mode to start from, and then adjust
the settings according to the desired driving cha-
racteristics. These settings are saved in an indi-
vidual driver profile.

An individual drive mode is only available if it is
first activated in the centre display.

Settings view

for individual drive mode.

1. Press

Settings

in the top view.

2. Press

My Car

Individual Drive Mode

and

select

Individual Drive Mode

3. In

Presets

, select a drive mode to start from:

Pure

Hybrid

Power

Possible adjustments apply to settings for:

•

Driver Display

•

Steering force

•

Powertrain Characteristics

•

Brake Characteristics

•

Suspension Control

•

ECO Climate

Using the internal combustion engine

An advanced control system determines the
extent to which the car is driven on internal com-
bustion engine, electric motor or both in parallel.

The primary function is to use the engine or
motor and the available energy in the hybrid bat-
tery as efficiently as possible, with regard to the
characteristics of the different drive modes as
well as the driver's request for power via the
accelerator pedal.

There are also cases where temporary limitations
in the system, or functions governed by legal
requirements aimed at maintaining a low level of
total emissions for the car, may use the internal
combustion engine to a greater extent.

The figure is schematic, the layout may vary depending on car model or updated software.

STARTING AND DRIVING

* Option/accessory.

430

Related information

•

Speed-dependent steering force (p. 280)

•

Level control

* and shock absorption (p. 431)

•

Foot brake (p. 433)

•

All-wheel drive (p. 432)

•

Hill descent control (p. 442)

•

Starting and stopping the combustion engine
in Twin Engine (p. 451)

•

Setting the time interval for the adaptive
cruise control

* (p. 306)

Maintain or increase the hybrid

battery's state of charge while

driving.

In some situations, it can be useful to be able to
control the hybrid battery's state of charge while
driving is in progress. The

Hold

and

Charge

functions are available in all drive modes.

"Hold" and "Charge" function buttons

These functions are activated in the centre dis-
play's function view.

Hold

Battery level sustained for
later use

The function maintains the
charge in the hybrid battery for
electric operation saves availa-
ble electrical energy for later

use, e.g. for driving in an urban environment or
through a residential area.

Hold

is available

regardless of the hybrid battery's state of charge.

The car works as for normal hybrid operation with
discharged battery where, in addition to re-using
brake-generated energy, for example, the car
starts the internal combustion engine more often
in order to maintain the charge in the battery.

Charge

Engine charges hybrid
battery

The function charges the hybrid
battery with support from the
internal combustion engine for
using increased electric opera-

tion at a later time. The function is not available
when the hybrid battery already has a high
charge level.

Symbol in the driver display

Hold

STARTING AND DRIVING

}}

* Option/accessory.

431

Charge

The

symbol is shown in the hybrid battery

gauge when

Hold

is activated and

when

Charge

is activated.

Related information

•

Economical driving (p. 449)

•

Drive modes (p. 425)

•

Electric operation range in urban environ-
ment (p. 451)

Level control

* and shock absorption

Level control regulates the car's suspension and
shock absorption characteristics automatically to
ensure the best comfort and functionality while
driving. It is also possible to adjust the level
manually in order to facilitate loading or entry
and exit.

Air suspension and shock absorption

The system is adapted according to the selected
drive mode and according to the speed of the
car. Using the air suspension, the car's ground
clearance is adjusted to a lower level at higher
speeds, which reduces wind resistance and
increases stability. Shock absorption is normally
set for the best possible comfort and is regulated
continuously depending on the road surface, the
car's acceleration, braking and cornering.

The driver display indicates
when level control is in pro-
gress.

The level cannot be regulated when the bonnet
or any side door is open.

Settings for level control

Entry assistance

The car can be lowered to facilitate entry and exit.

Activating entry assistance via the centre display:

1. Press

Settings

in the top view.

2. Press

My Car

Mirrors and Easy Entry

3. Select

Easy Entry and Exit Suspension

Control

> When the car is parked and switched off,

the car is lowered (level control stops if a
door is opened and there may be a cer-
tain delay before level control resumes
after the door has been closed). When the
car is started and begins to move, the car
will rise to the height setting for the drive
mode selected.

Deactivation of air suspension and level
control

In certain cases, the function must be deacti-
vated, e.g. before the car is raised with a jack

The difference in level created by raising the car
with a jack can otherwise cause problems for the
air suspension.

Deactivating the function via the centre display:

1. Press

Settings

in the top view.

2. Press

My Car

Parking Brake and

Suspension

3. Select

Disable Leveling Control

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432

Loading mode

Use the buttons in the cargo area to regulate the
height of the car's rear section and facilitate
loading/unloading or when connecting/discon-
necting a trailer. See the section "Loading".

During parking

During parking, make sure you allow adequate
space above and below the car since the car's
ground clearance may vary e.g. depending on the
outside temperature, how the car is loaded, the
use of loading mode or the drive mode that is
selected after starting.

The level may also be adjusted a period after the
car is parked. This is to compensate for any
height changes that may occur due to tempera-
ture changes in the air springs when the car
cools down.

During transport

During transport of the car on a ferry, train or
truck, the car must be lashed around the tyres
and not around other parts of the chassis.
Changes in the air suspension may occur during
transport, which could affect the lashing nega-
tively.

Related information

•

Drive modes (p. 425)

•

Recommendations for loading (p. 229)

All-wheel drive

All-wheel drive, AWD (All Wheel Drive), means
that the car is driving all four wheels at the same
time, which improves traction.

The electric motor that drives the rear wheels
enables electric all-wheel drive functionality.

To achieve the best possible traction and prevent
wheel spin the motive force is distributed auto-
matically to the wheels with the best grip. The
system continuously calculates the need for tor-
que to the rear wheels, and can immediately
redistribute up to half of the motor's torque to the
rear wheels.

All-wheel drive also has a stabilising effect at
higher speeds. Under normal driving conditions,
the majority of power is transmitted to the front
wheels. When stationary, the all-wheel drive is
always engaged in preparation for maximum trac-
tion during acceleration.

All-wheel drive characteristics vary depending on
the selected drive mode.

Related information

•

Drive modes (p. 425)

•

Low speed control (p. 441)

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433

Brake functions

The car's brakes are used to reduce the speed
or prevent the car from rolling.

Besides the foot brake and parking brake, the car
is equipped with several automatic brake assist
functions. These can assist the driver by not
needing to keep his/her foot on the brake pedal
when stationary at a traffic light, when starting on
an uphill gradient or when driving on a downhill
gradient.

Depending on the car's equipment, the following
auto braking functions are available:

•

Automatic braking when stationary (Auto
Hold)

•

Hill start assist (Hill Start Assist)

•

Auto braking after a collision

•

City Safety

•

Hill descent control (Hill Descent Control)

Related information

•

Foot brake (p. 433)

•

Parking brake (p. 436)

•

Hill descent control (p. 442)

•

Hill start assist (p. 439)

•

Automatic braking when stationary (p. 440)

•

Auto braking after a collision (p. 436)

Foot brake

The foot brake is part of the brake system.

The car is equipped with two brake circuits. If a
brake circuit is damaged, the brake pedal will
engage deeper. Higher pressure on the pedal will
therefore be needed to produce the normal brak-
ing effect.

WARNING

In a de-energised car with the electric motor

and fuel-driven engine switched off it is not

possible to brake the car.

In very hilly terrain or when driving with a heavy
load, the brakes can be relieved by using engine
braking in gear position B.

Use drive mode

Off Road

for increased engine

braking while driving on steep downhill gradients
at low speeds.

Anti-lock braking system

The car has anti-lock brakes, Anti-lock Braking
System (ABS), which can prevent the wheels
from locking while braking and allows maintained
steering control. Vibration may be felt in the
brake pedal when this is engaged and this is nor-
mal.

A short test of the ABS system is made automat-
ically after the car has been started when the
driver releases the brake pedal. A further auto-
matic test of the system may be made at low

speed. The test may be felt as pulses in the
brake pedal.

Light braking charges the hybrid battery

The electric motor's engine brake is used during
light braking. The car's kinetic energy is then
converted to electrical energy instead, which is
used to charge the hybrid battery. Battery charg-
ing with electric motor braking is indicated in the
driver display, see the section "Hybrid related
information in the driver display".

This function is active in the speed interval
150-5 km/h (93-3 mph). During heavier braking,
as well as outside the speed interval, braking is
supplemented by the hydraulic brake system. The
driver's display shows this by the indicator being
down in the red zone.

The driver display indicates charging during electric

motor braking.

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434

Braking on wet roads

When driving for a prolonged period of time in
heavy rain without braking, the braking effect may
be delayed slightly when next using the brakes.
This may also be the case after a car wash. It is
then necessary to depress the brake pedal more
forcefully. You should therefore maintain a
greater distance to the vehicles in front.

Brake the car firmly after driving on wet roads or
using a car wash. This warms up the brake discs,
enabling them to dry faster and protecting them
against corrosion. Bear in mind the current traffic
situation when braking.

Braking on salted roads

When driving on salted roads, a layer of salt may
form on the brake discs and brake linings. This
may extend braking distance. You should there-
fore maintain a greater safety distance to vehi-
cles in front. In addition, make sure you do the
following:

•

Brake now and again to remove any layer of
salt. Make sure that other road users are not
put at risk by the braking.

•

Gently depress the brake pedal after finish-
ing driving and before starting your next trip.

Maintenance

To keep the car as safe and reliable as possible,
follow the Volvo service intervals as specified in
the Service and Warranty Booklet.

New and replaced brake linings and brake discs
do not provide optimal braking effect until they
have been "worn in" a few hundred kilometres.
Compensate for the reduced braking effect by
depressing the brake pedal harder. Volvo recom-
mends only fitting brake linings that are approved
for your Volvo.

IMPORTANT

The wear on the brake system's components
must be checked regularly.

Contact a workshop for information about the
procedure or engage a workshop to carry out
the inspection - an authorised Volvo work-
shop is recommended.

Symbols in the driver display

Symbol

Specification

Check the brake fluid level. If the
level is low, fill with brake fluid and
check for the cause of the brake
fluid loss.

Fault in pedal sensor.

Symbol

Specification

Constant glow for 2 seconds when
the engine is started: Automatic
function check.

Constant glow for more than 2
seconds: Fault in the ABS system.
The car's normal brake system is
still working, but without the ABS
function.

If the message

Brake pedal

Cha-

racteristics changed Service
required

is shown, the system for

"Brake-by-wire" is disengaged. The
brake pedal engages deeper and a
higher pedal pressure is required
to achieve braking effect.

STARTING AND DRIVING

435

WARNING

If both the warning lamps for brake fault and

ABS fault illuminate at the same time, a fault

has occurred in the brake system.

•

If the level in the brake fluid reservoir is
normal at this stage, drive carefully to the
nearest workshop and have the brake
system checked - an authorised Volvo
workshop is recommended.

•

If the brake fluid is below the MIN level in
the brake fluid reservoir, do not drive fur-
ther before topping up the brake fluid.
The reason for the loss of brake fluid
must be investigated.

Related information

•

Brake functions (p. 433)

•

Brake assistance (p. 435)

•

Brake lights (p. 148)

•

Emergency brake lights (p. 435)

•

Emergency brake lights

Emergency brake lights are activated to alert
vehicles behind about heavy braking. The func-
tion means that the brake light flashes instead of
- as in normal braking - shining with a constant
glow.

The emergency brake lights are activated during
heavy braking or if the ABS system is activated at
high speeds. After emergency braking to a low
speed, the brake lights return from flashing to the
normal constant glow. The car's hazard warning
flashers are activated at the same time. These
flash until the driver accelerates the car to a
higher speed again or switches off the hazard
warning flashers.

Related information

•

Foot brake (p. 433)

•

Hazard warning flashers (p. 148)

•

Brake lights (p. 148)

Brake assistance

The brake assist system, BAS (Brake Assist
System), helps to increase brake force during
braking, thereby shortening the braking distance.

The system detects the way in which the driver
brakes and increases brake force where neces-
sary. The brake force can be boosted up to the
level when the ABS system is engaged. The
function is suspended when the pressure on the
brake pedal decreases.

Related information

•

Foot brake (p. 433)

STARTING AND DRIVING

* Option/accessory.

436

Auto braking after a collision

In the event of a collision in which the activation
level is reached for the pyrotechnic seatbelt ten-
sioners or airbags, or if a collision with a large
animal is detected, the car's brakes are automat-
ically applied. This function is to prevent or
reduce the effects of any subsequent collision.

After a serious collision there is a risk that it is no
longer possible to control and steer the car. In
order to avoid or mitigate a possible further colli-
sion with a vehicle or an object in the vehicle's
path, the auto braking system is activated auto-
matically and brakes the car in a safe manner.

Brake lights and hazard warning lights are acti-
vated during braking. When the car has stopped,
the hazard warning lights continue to flash and
the parking brake is applied.

If braking is not appropriate, e.g. if there is a risk
of being hit by following traffic, the system can be
overridden by the driver depressing the accelera-
tor pedal.

The function assumes that the brake system is
intact after the collision.

See also the sections "Rear Collision Warning"
and "Blind Spot Information".

Related information

•

Brake functions (p. 433)

•

Seatbelt tensioner (p. 63)

•

Airbags (p. 67)

•

Rear Collision Warning (p. 358)

•

BLIS

* (p. 358)

Parking brake

The parking brake prevents the car from rolling
away from stationary by means of mechanically
locking/blocking two wheels.

The control for the parking brake is located in the tunnel

console between the seats.

A faint electric motor noise can be heard when
the electrically-operated parking brake is being
applied. The noise can also be heard during the
automatic function checking of the parking brake.

If the car is stationary when the parking brake is
applied then it only acts on the rear wheels. If it is
applied when the car is moving then the normal
foot brake is used, i.e. the brake acts on all four
wheels. Brake function changes over to the rear
wheels when the car is almost stationary.

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437

Related information

•

Brake functions (p. 433)

•

Using the parking brake (p. 437)

•

In the event of a fault in the parking brake
(p. 439)

Using the parking brake

Use the parking brake to prevent the car from
rolling from stationary.

Applying the parking brake

1. Pull the control upward.

> The symbol in the driver display illumi-

nates when the parking brake is applied.

2. Check that the car is stationary.

Symbol in the driver display

Symbol

Specification

The symbol is illuminated when the
parking brake is applied.

If the symbol flashes, it indicates a
fault has occurred. Read the mes-
sage on the driver display.

Automatic application

The parking brake is applied automatically:

•

if the Auto hold function (automatic braking
when stationary) is activated and the car has
been stationary for approx. 5 minutes.

•

when gear position P is selected on a steep
hill.

•

when the car is switched off and the "Auto-
matic activation of parking brake" is acti-
vated

Emergency brake

In an emergency, the parking brake can be
applied when the car is in motion by pulling and
holding up the control. Braking stops when the
control is released.

NOTE

An acoustic signal sounds while emergency
braking is active at high speeds.

See heading "Settings for parking brake".

STARTING AND DRIVING

438

Releasing the parking brake

Releasing manually

1. Depress the brake pedal firmly.

2. Press the control down.

> The parking brake releases and the sym-

bol in the driver display extinguishes.

Releasing automatically

1. Put the seatbelt on.

2. Depress the brake pedal firmly.

3. Start the car.

4. Select gear position D or R and depress the

accelerator pedal.
> The parking brake releases and the sym-

bol in the driver display extinguishes.

NOTE

When the car is first started, the parking
brake can be released automatically without
the seatbelt fastened.

Parking on a hill

WARNING

Always use the parking brake when parking

on an inclined surface. Engaging a gear or the

automatic transmission's P position is not suf-

ficient to hold the car stationary in all situa-

tions.

If the car is parked facing uphill:

•

Turn the wheels away from the kerb.

If the car is parked facing downhill:

•

Turn the wheels towards the kerb.

Heavy load uphill

A heavy load, such as a trailer, can cause the car
to roll backward when the parking brake is
released automatically on a steep incline. Avoid
this by pulling the control upwards while driving
the car away. Release the control when the
engine achieves traction.

Settings for parking brake

Automatic activation of the parking brake is
selected via the centre display.

Automatic activation when the car is switched off:

1. Press

Settings

in the top view.

2. Press

My Car

Parking Brake and

Suspension

and deselect/select the func-

tion

Auto Activate Parking Brake

Related information

•

Parking brake (p. 436)

•

In the event of a fault in the parking brake
(p. 439)

•

Automatic braking when stationary (p. 440)

STARTING AND DRIVING

439

In the event of a fault in the parking

brake

Contact an authorised Volvo workshop if it is not
possible to release or apply the parking brake
after several attempts.

An acoustic warning signal sounds when driving
with the parking brake applied.

If the car must be parked before a possible fault
is rectified, then the wheels must be turned as for
parking on a hill

and the gear selector must be

in position P.

Low battery voltage

If the battery voltage is too low then the parking
brake can neither be released nor applied. Con-
nect a donor battery if the battery voltage is too
low.

Replacing the brake linings

The rear brake linings must be replaced at a
workshop due to the design of the electrically-
operated parking brake - an authorised Volvo
workshop is recommended.

Symbols in the driver display

Symbol

Specification

If the symbol flashes, it indicates a
fault has occurred. See the mes-
sage in the driver display.

Fault in brake system. See the
message in the driver display.

Information message in driver dis-
play.

Message examples:

•

Parking brake

Service required

•

Parking brake

System overheated

•

Parking brake

Not released

•

Parking brake

Cannot hold car

•

Parking brake

Temporarily unavailable

Related information

•

Brake functions (p. 433)

•

Using the parking brake (p. 437)

•

Parking brake (p. 436)

•

Using jump starting with another battery
(p. 417)

Hill start assist

Hill start assist, Hill Start Assist (HSA), prevents
the car from rolling backwards when starting on
an uphill gradient. When reversing uphill, it pre-
vents the car from rolling forwards.

The function means that the pedal pressure in
the brake system remains for several seconds
while the driver's foot is moved from brake pedal
to accelerator pedal.

The temporary braking effect releases after sev-
eral seconds or when the driver accelerates.

Hill start assist is available even if the function for
automatic braking when stationary (Auto hold) is
deactivated.

Related information

•

Brake functions (p. 433)

•

Automatic braking when stationary (p. 440)

See section "Using the parking brake".

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440

Automatic braking when stationary

Automatic braking when stationary (Auto hold)
means that the driver can release the brake
pedal while maintaining braking effect when the
car has stopped at traffic lights or a junction.

Function

When the car has stopped, the brakes are acti-
vated automatically. The function can use either
foot brake or parking brake to hold the car sta-
tionary and it works on all gradients. When the
accelerator pedal is depressed again, the brakes
are released.

When braking to a stop on a downhill or uphill
gradient - depress the brake pedal a bit harder
before releasing to ensure that the car does not
roll at all.

When stationary or when is the car is switched
off, the parking brake is applied after approx. 5
minutes.

Automatic deactivation

The function is deactivated automatically:

•

when the driver's door is open and the driv-
er's seatbelt is unfastened.

Switch for automatic brake

An indicator in the button illuminates when the function

is activated.

Activate or deactivate Auto hold with the switch
in the tunnel console. The function remains deac-
tivated until it is reactivated.

If the function is active and holds the
car with the foot brake (A-symbol illu-
minated) then the brake pedal must be
depressed at the same time as the

button is depressed in order to deactivate.

When the function is deactivated, hill start assist
(HSA) remains active to prevent the car from roll-
ing backwards when starting on an uphill gradi-
ent.

Symbols in the driver display

Symbol

Specification

The symbol is illuminated when the
function uses the foot brake to
keep the car stationary.

The symbol is illuminated when the
function uses the parking brake to
keep the car stationary.

Related information

•

Brake functions (p. 433)

•

Hill start assist (p. 439)

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441

Low speed control

The low speed control function Low Speed
Control (LSC) facilitates and improves traction
for driving off-road and on slippery surfaces,
such as with a caravan on grass or a boat trailer
on a launch ramp.

The function is included in drive mode Off Road.

The function is adapted for off-road driving and
driving with a trailer at low speed, up to approx.
40 km/h (25 mph).

With low-speed control, low gears and all-wheel
drive are prioritised, which help to avoid wheel-
spin and provides better traction on all wheels.
The accelerator pedal is less responsive in order
to facilitate traction and speed control at low
speed.

The function is activated together with Hill
Descent Control (HDC) which means that the
speed down steep downhill gradients can be
controlled with the accelerator pedal and it
reduces the need to use the brake pedal. The
system facilitates a low and even speed while
driving on steep downhill gradients.

Activating low speed control, LSC

•

Select the Off Road drive mode in order to
activate the function.

•

Select a different drive mode in order to
deactivate.

NOTE

When LSC with HDC is activated by the OFF
ROAD driving mode, the feel of the accelera-
tor pedal and engine response are changed.

NOTE

The driving mode is not designed to be used
on public roads.

NOTE

The function is deactivated when driving at
higher speeds and must be reactivated at a
lower speed, if required.

Related information

•

Brake functions (p. 433)

•

Hill descent control (p. 442)

•

Drive modes (p. 425)

STARTING AND DRIVING

442

Hill descent control

Hill descent control, Hill Descent Control
(HDC), is a low speed function with enhanced
engine braking. The function makes it possible
to increase or reduce vehicle speed on steep
downhill gradients using only the accelerator
pedal, without using the foot brake.

The function is included in drive mode Off Road.

Hill descent control is adapted for off-road driv-
ing at low speeds and facilitates driving on steep
downhill gradients with difficult surfaces. The
driver does not need to use the brake pedal, but
can instead focus on steering.

WARNING

HDC does not work in all situations but is

designed merely as a supplementary aid.
The driver always bears ultimate responsibility

for ensuring that the vehicle is driven safely.

Function

Hill descent control allows the car to roll at
inching speed both forward and backward, assis-
ted by the brake system. The speed can be
increased by using the accelerator pedal. When
the accelerator pedal is then released the car
slows back down to crawling speed, regardless of
the gradient of the hill and without the need for
the foot brake to be used. The brake lights are
switched on when the function is operating.

The driver can brake and reduce crawling speed,
or stop the car at any time by using the foot
brake.

The function is activated together with Low
Speed Control (LSC) which facilitates driving and
improves traction for driving off-road and on slip-
pery surfaces. The systems are designed for use
at low speed, up to approx. 40 km/h (25 mph).

Activating hill descent control, HDC

Hill descent control only works at low speeds.

•

Select the Off Road drive mode in order to
activate the function.

•

Select a different drive mode in order to
deactivate. If the drive mode is changed while
driving on a steep downhill gradient, the
braking effect will gradually decrease.

Points to remember when driving with HDC

•

HDC can be used in gear position D, R, and
with 1st or 2nd gear with manual gear
changing.

•

It is not possible to change to 3rd gear or
higher with manual gear changing.

NOTE

When LSC with HDC is activated by the OFF
ROAD driving mode, the feel of the accelera-
tor pedal and engine response are changed.

NOTE

The driving mode is not designed to be used
on public roads.

NOTE

The function is deactivated when driving at
higher speeds and must be reactivated at a
lower speed, if required.

Related information

•

Brake functions (p. 433)

•

Low speed control (p. 441)

•

Drive modes (p. 425)

STARTING AND DRIVING

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443

Driving in water

Driving in water means that the car is driven
through deep water on a water-covered road-
way. Driving in water must be carried out with
great caution.

Note the following in order to prevent damage to
the car when driving through water (e.g. on floo-
ded roads):

•

The water level must not be higher than the
floor of the car. If possible, check the depth
at the deepest point before starting to drive
through the water. Extra caution should be
exercised when passing through flowing
water.

•

Always change to

Off Road

drive mode

before driving through water in order to
ensure that the internal combustion engine is
running.

•

Do not drive faster than walking pace.

•

Do not stop the car in the water. Drive for-
ward carefully or reverse the car back out of
the water.

•

Remember that waves created by oncoming
traffic may rise above the level for the floor of
the car.

•

Avoid driving through salt water (corrosion
risk).

IMPORTANT

Parts of the car (e.g. engine, gearbox, drive-
line or electrical components) may be dam-
aged when driving through water with a level
higher than the floor of the car. Damaged
caused to a component caused by submer-
sion, hydrolock or lack of oil is not covered by
the warranty.

In the event of stalling in water, do not try to
restart. Instead, tow the car out of the water
and transported on a low loader to a work-
shop. An authorised Volvo workshop is rec-
ommended.

When the water has been passed, depress the
brake pedal lightly and check that full brake func-
tion is achieved. Water and mud for example can
make the brake linings wet resulting in delayed
brake function.

If necessary, clean the contact for the trailer cou-
pling after driving in water and mud.

Related information

•

Towing (p. 460)

•

Recovering the car (p. 461)

Overheating in the engine and drive

system

Under special conditions, for example hard driv-
ing in hilly terrain and hot climate, there is a risk
that the engine and drive system may overheat -
in particular with a heavy load.

•

In the event of overheating, the engine's
power may be limited temporarily.

•

Remove any auxiliary lamps from in front of
the grille when driving in hot climates.

•

If the temperature in the engine's cooling
system becomes too high then a warning
symbol is illuminated and the driver display
shows the message

Engine temperature

High temperature Stop safely

. Stop the

car in a safe way and allow the engine to run
at idling speed for several minutes and cool
down.

•

If the message

Engine temperature

High

temperature Turn off engine

Engine

coolant

Level low, turn off engine

shown, stop the car and switch off the
engine.

•

In the event of overheating in the gearbox, an
alternative gear shift program will be
selected. In addition, a built-in protection
function is activated that, amongst other
things, illuminates a warning symbol and the
driver display shows the message

Transmission warm

Reduce speed to

lower temperature

Transmission hot

Volvo XC90 Excellence (2018 year). Instruction - part 26