brake light VOLVO XC90 TWIN ENGINE 2019 Service Manual

STARTING AND DRIVING
466Hill Descent Control
The function for assisting when driving downhill,
Hill Descent Control (HDC), is a low-speed
function with increased engine braking. The
function makes it possible to increase or
decrease the vehicle's speed on steep downhill
gradients by only using the accelerator pedal,
without applying the brakes.
The function is included in the Off Road drive
mode.
HDC is designed for driving on rough roads at
low speeds and downhill gradients with slippery
or otherwise difficult road surfaces. The driver
does not need to use the brake pedal but can
instead focus on steering.
WARNING
HDC is only intended to be a supplementary
braking aid and it does not function in all sit-
uations.
The driver is always ultimately responsible for
operating the vehicle in a safe manner.
FunctionHill Descent Control allows the vehicle to move
forward or backward at very low speeds assisted
by the brake system. The driver can increase the
speed by pressing the accelerator pedal. When
the accelerator pedal is released, the vehicle will
return to very low speed regardless of how steep the hill is and without the brakes needing to be
applied. The brake lights will illuminate when the
function is activated.
The driver can brake to stop or slow the vehicle
at any time by depressing the brake pedal.
HDC is activated along with Low Speed Control
(LSC), which facilitates and improves traction and
control on rough and slippery surfaces. The sys-
tem is intended to be used at low speeds, up to
approximately 40 km/h (25 mph).
To keep in mind when using HDC

If the function is switched off while driving on
a steep downhill gradient, braking effect will
be gradually reduced.
HDC can be used in gear positions D and R,
and in manual gears 1 or 2.
It is not possible to manually shift to third
gear or higher when HDC is active.
NOTE When LSC with HDC is activated in the OFF
ROAD drive mode, the feel of the accelerator
pedal and engine response will change.
NOTE
This drive mode is not designed to be used
for normal street driving.
NOTE The function is deactivated when driving at
high speeds and must be reactivated at lower
speeds if so desired.
Related information

Activating and deactivating Hill Descent Con-
trol using the function button (p. 467)
Changing drive mode (p. 459)
Low Speed Control (p. 464)
All Wheel Drive (AWD) (p. 452)

STARTING AND DRIVING
472Preparing for a long trip
It is important to have the vehicle's systems and
equipment checked carefully before driving long
distances.
Check that:
the engine is running properly and that fuel
consumption is normal
there are no leaks (fuel, oil or other fluid)
the brake pedal is functioning optimally
all lights are working ‒ adjust the headlight
height if the vehicle is carrying a heavy load
tire tread depth and air pressure are at cor-
rect levels. Change to snow tires when driv-
ing in areas where there is a risk of snowy or
icy roads
the start battery is sufficiently charged
the wiper blades are in good condition
Related information
Checking tire pressure (p. 567)
Filling washer fluid (p. 662)
Winter driving (p. 472)
Economical driving (p. 467)
Vehicle modem settings (p. 545)
Loading recommendations (p. 598)
Driving with a trailer (p. 483)
Pilot Assist (p. 316)
Speed limiter (p. 283)
Tire sealing system (p. 582) Winter driving
It is important to check the vehicle before driving
in cold/snowy conditions to make sure it can be
driven safely.
Before the cold season arrives: Make sure the engine coolant contains 50%
antifreeze. This mixture helps protect the
engine from frost erosion down to
approx. -35 °C (-31 °F). Do not mix different
types of antifreeze as this could pose a
health risk.
Keep the fuel tank well filled to prevent con-
densation from forming.
Check the viscosity of the engine oil. Oil with
low viscosity (thinner oil) improves cold-
weather starting and reduces fuel consump-
tion when driving with a cold engine.
CAUTION Low-viscosity oil should not be used with hard
driving or in hot weather.

Check the condition and charge level of the
start battery. Cold weather places greater
demands on the start battery and reduces its
capacity.
Use washer fluid containing antifreeze to
help prevent ice from forming in the washer
fluid reservoir.

STARTING AND DRIVING
473
Slippery driving conditionsFor optimal traction and roadholding, Volvo rec-
ommends using snow tires on all wheels when-
ever there is a risk of snow or ice on the road.
NOTECertain countries require use of winter tires
by law. Not all countries permit the use of
studded tires.
Practice driving on slippery surfaces under con-
trolled conditions to learn how the vehicle reacts.
Related information

Snow tires (p. 581)
Snow chains (p. 581)
Braking on salted roads (p. 441)
Braking on wet roads (p. 441)
Filling washer fluid (p. 662)
Start battery (p. 627)
Replacing windshield wiper blades (p. 660)
Changing rear window wipers (p. 659)
Refilling coolant (p. 625) Driving through standing water
Driving the vehicle through a deep pool of stand-
ing water on a water-covered roadway is called
fording. This must be done with great caution.
To prevent damage to the vehicle when driving
through water (e.g. on flooded roads):
Do not drive in water higher than the floor of
the vehicle. If possible, check the depth of
the water at its deepest point before driving
through it. Be particularly careful when driv-
ing through flowing water.
Always select the
Off Road drive mode
before driving in water to ensure the gasoline
engine is running.
Do not drive faster than walking speed.
Do not stop the vehicle in the water. Drive
carefully forward or back the vehicle out of
the water.
Remember that waves created by passing
vehicles could cause the water level to rise
above the vehicle's floor level.
Avoid driving through salt water to help avoid
the risk of corrosion.
CAUTION Parts of the vehicle (e.g. engine, transmission,
driveline, electrical components, etc.) can be
damaged if the vehicle is driven through water
higher than its floor level. Damage to any
components caused by flooding, vapor lock or
insufficient oil is not covered under warranty.
If the engine stalls while the vehicle is in
water, do not attempt to restart it. Have the
vehicle towed on the bed of a tow truck to a
workshop - an authorized Volvo workshop is
recommended.
CAUTION
Because it can be difficult to determine the
water depth, avoid driving through standing or
running water.
When you have passed the water, press lightly on
the brake pedal and check that the brakes are
functioning properly. Water, mud, slush, etc. can
make the brake linings slippery, resulting in
delayed braking effect.
If the vehicle is equipped with a trailer coupling
contact, clean the contact after driving in water or
mud.
Related information

Recovery (p. 489)
Low Speed Control (p. 464)

||STARTING AND DRIVING
* Option/accessory.
484
Follow applicable regulations regarding per-
mitted speed and weight.
Drive slowly when towing a trailer up a long
and steep incline.
The maximum trailer weights given only apply
to altitudes up to 1000 meters (3280 feet)
above sea level. At higher altitudes, engine
power (and thus the vehicle's climbing ability)
is decreased due to the reduced air density,
and the maximum trailer weight must there-
fore be reduced. The weight of the vehicle
and trailer must be decreased by 10% for
each additional 1000 m (3280 feet) or part
thereof.
Avoid driving with a trailer on inclines of more
than 12%.
Avoid overloading and other incorrect use.
The trailer's brakes must be balanced with
the vehicle's brakes to help ensure safe
stops (follow applicable local regulations).
NOTE To facilitate towing a trailer in a vehicle equip-
ped with pneumatic suspension*, select: the
Suspension Control
Dynamic
setting in
Individual drive mode.
CAUTION
Bumper-attached trailer hitches must not
be used on Volvos, nor should safety
chains be attached to the bumper.
Trailer hitches attaching to the vehicle
rear axle must not be used.
Never connect a trailer's hydraulic brake
system directly to the vehicle brake sys-
tem, nor a trailer's lighting system directly
to the vehicle lighting system. Consult
your nearest authorized Volvo retailer for
correct installation.
When towing a trailer, the trailer's safety
chains or wire must be correctly fastened
to the attachment points provided in the
trailer hitch on the vehicle. The safety
chain or wire must never be fastened to
or wound around the towing ball.
NOTE The optional detachable trailer hitch may not
be available in all markets or on all models.
Consult your Volvo retailer.
NOTE
Extreme weather conditions, towing a trailer,
driving at high altitudes and fuel quality are
factors that significantly increase a vehicle's
fuel consumption.
Trailer weights
WARNING Please adhere to the recommendations provi-
ded for trailer weight. If the recommendations
are not followed, the vehicle and trailer may
be difficult to control during evasive maneu-
vers and braking.
NOTE
The specified maximum trailer weights are
those permitted by Volvo. National vehicle
regulations may set additional restrictions on
trailer weight and speed. The trailer hitches
may be certified for higher towing weights
than the vehicle is permitted to tow.
Self-leveling suspension*The vehicle's self-leveling system attempts to
keep the vehicle at a constant level, regardless of
load (up to the maximum permitted weight).
When the vehicle is stationary, the rear end of the
vehicle will be slightly lowered, which is normal.
Driving in hilly terrain or hot weatherIn certain conditions, there is a risk of overheat-
ing when driving with a trailer. If overheating of
the engine and drive system is detected, a warn-
ing symbol will illuminate in the instrument panel
along with a message.

STARTING AND DRIVING
}}
* Option/accessory. 485
The automatic transmission selects the optimal
gear for the current load and engine speed.
Steep inclines
Do not lock the automatic transmission into a
higher gear than what the engine can handle ‒ it
is not always preferable to drive in high gears at
low rpm.
Parking on a hill
1. Depress the brake pedal.
2. Apply the parking brake.
3. Put the gear selector in P.
4. Release the brake pedal.
Put chocks behind the wheels when the vehicle
is parked on a hill with a trailer attached.
Starting on a hill
1. Depress the brake pedal.
2. Put the gear selector in D.
3. Release the parking brake.
4. Release the brake pedal and start driving.
Related information
Trailer Stability Assist* (p. 485)
Checking trailer lights (p. 486)
Towing capacity and tongue weight (p. 670)
Overheating of engine and transmission
(p. 479) Trailer Stability Assist*
Trailer Stability Assist (TSA 8
) is a function
designed to help stabilize a vehicle that is tow-
ing a trailer when the vehicle and trailer have
begun to sway. The function is part of the Elec-
tronic Stability Control system ESC 9
.
Reasons for swayingA vehicle towing a trailer may begin to sway for
various reasons. Normally this only occurs at high
speeds. However, if the trailer is overloaded or
unevenly distributed, e.g. too far back, there is a
risk of swaying even at low speeds.
Swaying may be caused by factors such as:
The vehicle and trailer are hit by a sudden,
strong crosswind.
The vehicle and trailer are traveling on an
uneven road or over a bump.
Sudden movements of the steering wheel.
Once swaying has begun, it can be difficult or
impossible to stop it. This makes the vehicle and
trailer difficult to control and there is a risk of
swerving into oncoming traffic or driving off the
road.
Trailer Stability Assist functionTrailer Stability Assist continuously monitors the
vehicle's movements, particularly lateral move- ments. If swaying is detected, the brakes are
applied individually on the front wheels, which has
a stabilizing effect on the vehicle and trailer. This
is often enough to enable the driver to regain
control of the vehicle.
If the Trailer Stability Assist function's first
attempt is not adequate to stop the swaying
motion, the brakes are applied on all wheels and
engine power is temporarily reduced. As the
swaying motion begins to decrease and the vehi-
cle and trailer have once again become stable,
TSA stops regulating the brakes/engine power
and the driver regains control of the vehicle.
NOTE
Trailer Stability Assist is deactivated if the
driver selects the sport mode by deactivating
ESC in the center display's menu system. Trailer Stability Assist may not intervene if the
driver tries to compensate for the swaying motion
by moving the steering wheel rapidly, because
the system will then not be able to determine if it
is the trailer or the driver causing the swaying.
8
Trailer Stability Assist
9 Electronic Stability Control

||STARTING AND DRIVING
* Option/accessory.
486 When Trailer Stability Assist is
activated, the ESC symbol is
displayed in the instrument
panel.
Related information

Driving with a trailer (p. 483)
Electronic Stability Control (p. 279) Checking trailer lights
When connecting a trailer, make sure that all of
the lights on the trailer are functioning before
starting to drive.
Trailer turn signals and brake lightsIf one or more of the turn signals or brake lights
on the trailer is not working, a symbol and mes-
sage will be displayed in the instrument panel.
The other lights on the trailer must be checked
manually by the driver before the vehicle is driven. Symbol
Message
Trailer turn indicator Right
turn indicator malfunction
Trailer turn indicator Left
turn indicator malfunction
Trailer brake light Malfunc-
tion If any of the trailer's turn signal lights is not work-
ing, the turn signal symbol in the instrument
panel will also flash more quickly than normal.
Trailer rear fog lightWhen a trailer is connected, the vehicle's rear fog
light may not illuminate and rear fog light func-
tionality is instead transferred to the trailer. If this
is the case, check to see if the trailer is equipped
with a rear fog light before activating the vehicle'sfog lights when driving with a trailer to help
ensure safe operation.
Checking trailer lights*
Automatic check
When the trailer has been connected to the vehi-
cle's electrical system, its lights can be checked
by automatically activating them. This function
helps the driver check that the trailer's lights are
functioning correctly before starting to drive.
In order to perform this check, the engine must
be turned off.
1. When a trailer is connected to the towbar, the message Automatic Trailer Lamp
Check will appear in the instrument panel.
2.

Acknowledge the message by pressing the
O button on the right-side steering wheel
keypad.
> The light check will begin.
3. Get out of the vehicle to perform the check. > All of the lights on the trailer will beginflashing, and then illuminate separately
one at a time.
4. Visually check that all of the trailer's lights are functioning correctly.
5. After a short time, all of the trailer's lights will start flashing again.
> The light check is completed.

STARTING AND DRIVING
}}
* Option/accessory. 489
Recovery
This section refers to transporting the vehicle
with a tow truck or similar vehicle.
Call a professional towing service for assistance.
In certain conditions, the towing eyelet can be
used to pull the vehicle onto a flatbed tow truck.
CAUTION Note that vehicles with Twin Engine must
always be towed raised with all wheels on the
tow truck.
For vehicles equipped with leveling control*:
If the vehicle is equipped with pneumatic suspen-
sion, this feature must be turned off before the
vehicle is lifted onto a tow truck. Turning off the
function in the center display.
1. Tap Settings in the Top view.
2.

Tap My Car Parking Brake and
Suspension .
3. Select Disable Leveling Control.
The vehicle's location and ground clearance
determine if it can be lifted onto a tow truck. If
the incline of the tow truck is too steep or if the
ground clearance under the vehicle is insufficient,
attempting to pull it up may result in damage. In
this case, the vehicle should only be lifted with
the tow truck's lifting equipment.
WARNING No person or object should be behind the tow
truck when the vehicle is lifted onto the bed
of the truck.
Related information

Attaching and removing the towing eyelet
(p. 488) HomeLink
®
*10
HomeLink ®11
is a programmable remote control,
integrated in the vehicle electrical system, that
can control up to three different devices (e.g.
garage door opener, alarm system, outdoor and
indoor lighting) and thereby replace the remote
controls for these.
General The illustration is generic – the design may vary.
Button 1
Button 2
Button 3
Indicator light
HomeLink ®
is delivered integrated in the rearview
mirror. The HomeLink ®
panel consists of three

||MAINTENANCE AND SERVICE
* Option/accessory.
636 Function
Ampere12 V outlet in trunk/cargo
compartment*
USB ports for iPad holders
B15 –
––
––
––
–Heated windshield*, left side
ShuntHeated windshield*, left side
40Headlight washers*
25Windshield washer
25–
–Horn
20Alarm siren*
5Brake system control module
(valves, parking brake)
40Wipers
30Rear window washer
25 Function
Ampere Heated windshield*, right side
40 Parking heater*
20 Brake system control module
(ABS pump)
40 –
– Heated windshield*, right side
Shunt Fed when ignition is on:
Engine control module; trans-
mission components, electrical
power steering, central electri-
cal module
5 Exterior vehicle sound (certain
markets)
5 Right-side headlight
7.5
Right-side headlight, some
models with LED C 15 –
– –
– –
– Airbags
5 Function
Ampere Left-side headlight
7.5
Left-side headlight, some
models with LED C 15 Accelerator pedal sensor 5
Transmission control module;
gear selector control module
15 Engine control module
5 –
– –
– –
– –
– Engine control module; actua-
tor; throttle unit; turbo-charger
valve
20 Solenoids; valve; engine cool-
ing system thermostat
10 Vacuum regulators; valve 7.5
Spoiler shutter control module;
radiator shutter control mod-
ule
5 –
–

MAINTENANCE AND SERVICE
}}
* Option/accessory. 639
Fuse pliers are provided on the inside of the fuse
box cover to assist in removing and inserting
fuses.
There are also spaces for several extra fuses in
the distribution box in the engine compart-
ment.
Positions

Fuses 1, 3-21, 23-36, 39-53 and 55-59 are
"Micro" fuses.
Fuses 2-22, 37-38 and 54 are "MCase"
fuses and should only be replaced by a work-
shop 17
. Function
Ampere–
––
––
–Movement sensor*
5Media player
5Instrument panel
5Center console buttons
5Sun sensor
5 Function
Ampere Sensus control module
20 –
– Steering wheel module
5 Module for start knob and
parking brake controls
5 Heated steering wheel* mod-
ule 15 –
– –
– –
– –
– Climate system control mod-
ule
10 –
– Data link connector OBD-II 10
Center display
5 Climate system blower module
(front)
40 Function
Ampere USB HUB
5 Instrument lighting; Interior
lighting; Rearview mirror auto-
dim function*; Rain and light
sensors*; Rear tunnel console
keypad, second row of seats* A
;
Power front seats *; Rear door
control panels; Climate system
blower module left/right
Power rear seats B
; Display for
rear seat convenience func-
tions B
; Rear seat massage
function B 7.5 Control module for driver sup-
port functions
5 Panoramic roof with sun cur-
tain*
20 Head-up display*
5 Passenger compartment light-
ing
5 –
–17
An authorized Volvo workshop is recommended.

||MAINTENANCE AND SERVICE
* Option/accessory.
648
WARNING
Never use more than one inlay mat at a
time on the driver's floor. If any other type
of floor mat is used, remove the original
mat from the driver's seat floor before
driving. All types of mats must be securely
anchored in the attachment points in the
floor. Make sure the floor mat does not
impede the movement of the brake pedal
or accelerator pedal in any way, as this
could be a serious safety hazard.
Volvo's floor mats are specially manufac-
tured for your vehicle. They must be prop-
erly secured in the attachment points in
the floor to help ensure they cannot slide
and become trapped under the pedals.
After vacuuming, a specially designed textile
cleaning agent should be used to remove stains
on floor mats. Floor mats should be cleaned with
products recommended by Volvo retailers.
Related information
Cleaning the interior (p. 645)
Cleaning the center display (p. 645)
Cleaning fabric upholstery and ceiling liner
(p. 647)
Cleaning the seat belt (p. 647)
Cleaning leather upholstery (p. 648)
Cleaning the leather steering wheel
(p. 649)
Cleaning interior plastic, metal and wood sur-
faces (p. 650) Cleaning leather upholstery
Only use cleaning agents and car care products
recommended by Volvo. Clean regularly and
treat stains immediately for best results. It is
important to vacuum before using a cleaning
agent.
Leather upholstery*Volvo's leather upholstery is treated to protect its
original appearance. Over time, sunlight, grease,
dirt, etc. could break down the protective layer.
This could result in scratches and cracking.
Leather upholstery is a natural product that
changes and acquires a beautiful patina over
time. Regular cleaning and treatments are
required to preserve the qualities and color of the
leather. Volvo offers a comprehensive product,
Volvo Leather Care Kit/Wipes, for cleaning and
treating leather upholstery that, when used as
directed, preserves the leather's protective coa-
ting.
For best results, Volvo recommends cleaning and
applying protective cream one to four times a
year (or more as needed). Volvo Leather Care Kit
951 0251 and Volvo Leather Softener 943
7429 are available for purchase at Volvo retailers.