2019 VOLVO XC90 TWIN ENGINE lights

STARTING AND DRIVING
}}
447
When shutting off
If the function is active and holding the
vehicle stationary using the normal
brakes (A symbol lit), the brake pedal
must be depressed while pressing the
button in order to deactivate Auto-hold.
The function will remain off until it is reactiva-
ted.
When Auto-hold is switched off, Hill Start
Assist (HSA) will remain active to help pre-
vent the vehicle from rolling backward when
starting up a hill.
Related information
Auto-hold brakes (p. 446) Hill Start Assist
The function for assisting when starting the vehi-
cle on inclines, Hill Start Assist (HSA), helps
prevent the vehicle from rolling backward when
starting on an uphill gradient. When backing up
a hill, HSA helps prevent the vehicle from rolling
forward.
The function retains pressure from the brake
pedal in the brake system for several seconds
after the brake pedal has been released.
This temporary braking effect is released after a
few seconds or when the driver begins driving.
Hill Start Assist is available even if the Auto-hold
brake function is switched off.
Related information
Auto-hold brakes (p. 446)
Brakes (p. 439) Braking assist after a collision
In a collision in which the activation level is
reached for the pyrotechnic seat belt tensioners
or airbags, or if a collision with a large animal is
detected, the vehicle's brakes will be automati-
cally activated. This function is intended to help
prevent or reduce the effects of any subsequent
collision.
After a serious collision, it may no longer be pos-
sible to control and steer the vehicle. In order to
avoid or mitigate a possible further collision with
a vehicle or an object in the vehicle's path, the
brake assist system is activated automatically to
help stop the vehicle safely.
The brake lights and hazard warning flashers are
activated during braking. When the vehicle has
stopped, the hazard warning flashers will con-
tinue to flash and the parking brake will be
applied.
If braking is not appropriate, e.g. if there is a risk
of being hit by passing traffic, the driver can over-
ride the system by depressing the accelerator
pedal.
This function assumes that the brake system is
intact after a collision.
Brake assist is part of the Rear Collision Warning
and Blind Spot Information safety systems.

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
}}
479
Emission controls
Three-way catalytic converter

Keep your engine properly tuned. Certain
engine malfunctions, particularly involving the
electrical, fuel or distributor ignition systems,
may cause unusually high three-way catalytic
converter temperatures. Do not continue to
operate your vehicle if you detect engine
misfire, noticeable loss of power or other
unusual operating conditions, such as engine
overheating or backfiring. A properly tuned
engine will help avoid malfunctions that
could damage the three-way catalytic con-
verter.
Do not park your vehicle over combustible
materials, such as grass or leaves, which can
come into contact with the hot exhaust sys-
tem and cause such materials to ignite under
certain wind and weather conditions.
Excessive starter cranking (in excess of one
minute), or an intermittently firing or flooded
engine can cause three-way catalytic con-
verter or exhaust system overheating.
Remember that tampering or unauthorized
modifications to the engine, the Engine Con-
trol Module, or the vehicle may be illegal and
can cause three-way catalytic converter or
exhaust system overheating. This includes:
altering fuel injection settings or compo-
nents, altering emission system components or location or removing components, and/or
repeated use of leaded fuel.NOTE Unleaded fuel is required for vehicles with
three-way catalytic converters.
Heated oxygen sensorsThe heated oxygen sensors monitor the oxygen
content of the exhaust gases. Readings are fed
into a control module that continuously monitors
engine functions and controls fuel injection. The
ratio of fuel to air into the engine is continuously
adjusted for efficient combustion to help reduce
harmful emissions.
Related information

Octane rating (p. 477)
Fuel (p. 476) Overheating of engine and
transmission
In demanding driving conditions, such as driving
in mountainous areas or hot weather, there is a
risk of the engine or transmission overheating,
especially when carrying heavy loads.
Engine power may be temporarily limited.
Remove any auxiliary lights mounted in front
of the grille when driving in hot weather.
If the temperature in the engine's cooling
system becomes too high, a warning symbol
will appear in the instrument panel along with
the message Engine temperature High
temperature Stop safely. Pull over to a safe location and let the engine idle for a few
minutes to cool down.
If the message
Engine temperature High
temperature Turn off engine or Engine
coolant Level low, turn off engine is dis- played, stop the vehicle and turn off the
engine.
If the transmission begins to overheat, an
alternative gear shifting program will be
selected. An integrated protective function
will also be activated, the warning symbol will
illuminate and the message Transmission
warm
Reduce speed to lower
temperature or Transmission hot Stop
safely, wait for cooling will be displayed in the instrument panel. Follow the recommen-
dations given by reducing speed or stopping

||STARTING AND DRIVING
480
the vehicle safely and letting the engine idle
for a few minutes to let the transmission
cool.
If the vehicle begins to overheat, the air con-
ditioning may be temporarily switched off.
After a prolonged period of driving in
demanding conditions, do not turn off the
engine immediately after stopping.
NOTE It is normal for the engine's cooling fan to
operate for a short time after the engine is
switched off.
Symbols in the instrument panel
Symbol
Meaning High engine temperature. Follow
the recommendations provided.
Low coolant level. Follow the rec-
ommendations provided.
Transmission hot/overheated/cool-
ing. Follow the recommendations
provided.
Related information

Refilling coolant (p. 625)
Driving with a trailer (p. 483)
Preparing for a long trip (p. 472) Battery drain
The electrical functions in the vehicle drain the
battery to varying degrees. Avoid using ignition
mode II when the engine is switched off. Use
ignition mode I instead, as this uses less electri-
cal current.
Note that certain accessories may also drain
power from the electrical system. Do not use
functions that use a lot of electrical current when
the engine is turned off. Examples of such func-
tions are: blower
headlights
windshield wipers
audio system (especially at high volume).
If the starter battery voltage is low, a message is
shown in the driver display. The vehicle's energy-
saving function will then turn off or reduce certain
functions, such as the blower and/or the audio
system.
– Charge the battery by starting the engine
and let it run for at least 15 minutes (driving
charges the battery faster than letting the
engine idle).
Related information
Start battery (p. 627)
Ignition modes (p. 437)

STARTING AND DRIVING
}}
481
Jump starting using another battery
If the start battery is discharged, current from
another battery can be used to start the vehicle. Jumper cable connecting points.
CAUTION
The charging point of the vehicle is only
intended for jump starting the vehicle in ques-
tion. The charging point is not intended for
jump-starting another vehicle. Using the
charging point to start another vehicle could
cause a fuse to blow, which would cause the
charging point to stop working.
If a fuse has blown, 12 V Battery Fuse failure
Service required will be displayed in the instru-
ment panel. Volvo recommends contacting an
authorized Volvo workshop. To avoid short circuits or other damage, the fol-
lowing steps are recommended when jump star-
ting the battery:
1.
Put the ignition in mode 0.
2.
Make sure the auxiliary battery (the battery
used to jump start the discharged battery)
has a voltage of 12 volts.
3. If the auxiliary battery is in another vehicle, turn off that vehicle's engine and make sure
that the vehicles are not touching each other.
4. Clamp the red jumper cable onto the auxiliary battery's positive (+) terminal (1).
CAUTION Connect the jump cable carefully to prevent
short circuits with other components in the
engine compartment.
5. Fold back the cover over your vehicle's posi-
tive (+) jump start terminal (2).
6.

Clamp the other end of the red jumper cable
to your vehicle's positive (+) jump start termi-
nal (2).
7. Clamp the black jumper cable onto the auxili- ary battery's negative (-) terminal (3).
8. Clamp the other end of the black jumper cable to your vehicle's negative (-) ground
point (4). 9. Make sure the jumper cables are securely
attached to help prevent sparks while jump
starting.
10. Start the engine of the assisting vehicle and let it run for a few minutes at a higher idling
speed than normal, about 1500 rpm.
11. Start your vehicle's engine. If the engine does not start, allow an additional 10
minutes of charging time and then try to start
the engine again.
NOTE When the engine is started under normal
conditions, the vehicle's electrical drive motor
is prioritized – the gasoline engine remains
off. This means that the electric motor has
"started" and the vehicle is ready to be driven
once the start knob has been turned clock-
wise. Start of the electric motor is indicated
by the indicator lights on the instrument panel
going out and its preselected theme illuminat-
ing.
CAUTION
Do not touch the connections between the
cable and the vehicle during the start attempt.
Risk of sparking.

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.