2018 VOLVO XC90 TWIN ENGINE trailer

||STARTING AND DRIVING
460
Charge
Engine charges hybrid
battery.
This function charges the
hybrid battery with the help of
the combustion engine for
increased use of the electric
motor at a later time. This function is not available
if the hybrid battery's charge level is already high.
Symbols in the instrument panel The symbol is displayed in the hybrid battery gauge
when Hold is activated. The symbol is displayed in the hybrid battery gauge
when Charge is activated.
Related information
• Using the electric motor only (p. 457)
• Economical driving (p. 456)
• Hybrid gauge (p. 87) Preparing 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. 557)
• Filling washer fluid (p. 650)
• Winter driving (p. 461)
• Economical driving (p. 456)
• Vehicle modem settings (p. 533)
• Loading recommendations (p. 586)
• Driving with a trailer (p. 472)
• Pilot Assist (p. 311)

STARTING AND DRIVING
462Driving 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.
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. 477)
• Low Speed Control (p. 453) Opening/closing the fuel filler door
A button on the instrument panel is used to
unlock the fuel filler door.
An arrow next to the fuel pump
symbol in the instrument panel
indicates the side of the vehicle
on which the fuel filler door is
located.

STARTING AND DRIVING
467
WARNINGCarbon monoxide is a poisonous, colorless,
and odorless gas. It is present in all exhaust
gases. If you ever smell exhaust fumes inside
the vehicle, make sure the passenger com-
partment is ventilated, and immediately return
the vehicle to a trained and qualified Volvo
service technician for correction.
Demanding drivingIn demanding driving conditions, e.g. when driving
in a hot climates, driving with a trailer or driving
for longer periods at higher altitudes (mountain
landscapes) than normal, it is recommended
switching to a higher octane fuel than AKI 91
6
or
changing gasoline brand to take full advantage of
your car's engine capacity and obtain the opti-
mum driving force.
Related information
• Fuel (p. 464)
• Emission controls (p. 467) 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. 465)
• Fuel (p. 464) 6
AKI (Anti Knock Index) is an average value of RON (Research Octane Nu\
mber) and MON (Motor Octane Number) - (RON)+(MON)/2

STARTING AND DRIVING
* Option/accessory.
468 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 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. 612)
• Driving with a trailer (p. 472)
• Preparing for a long trip (p. 460)
• Gear indicator* (p. 442)

STARTING AND DRIVING
}}
* Option/accessory. 471•
If contact occurs, flush the affected area
immediately with water. Obtain medical
help immediately if eyes are affected.
• Never expose the battery to open flame
or electric spark. Do not smoke near the
battery. Failure to follow the instructions
for jump starting can lead to injury.
NOTE The vehicle cannot be started if the hybrid
battery is discharged.
Related information
•
Starting the vehicle (p. 424)
• Ignition modes (p. 427)
• Adjusting the steering wheel (p. 199)
• Selecting ignition mode (p. 428) Detachable towbar*
Volvo recommends the use of Volvo towbars
that are specially designed for the vehicle.
NOTE The optional detachable trailer hitch may not
be available in all markets or on all models.
Consult your Volvo retailer.
Ball holder
Cotter pin
Towbar assembly
Locking bolt
Safety wire attachment bracket
Installing the ball holder1. If necessary, remove the cotter pin from the
locking bolt and slide the locking bolt out of
the towbar assembly.
2. Slide the ball holder into the towbar assem- bly.
3. Align the hole in the ball holder with the one in the towbar assembly.
4. Slide the locking bolt through the towbar assembly/ball holder.
5. Insert the cotter pin in the hole at the end of the locking bolt.
WARNING •
Be sure the towbar is securely locked in
position before attaching anything to it.
• Always attach the trailer's safety wire
securely to the towbar's safety wire
attachment bracket.
Removing the ball holder1. Remove the cotter pin from the locking bolt
and slide the locking bolt out of the ball
holder/towbar assembly.
2. Pull the ball holder out of the towbar assem- bly.

||STARTING AND DRIVING
472
Stowing the ball holder
WARNING
When not in use, the detachable ball holder
should always be properly stowed in the des-
ignated location under the floor of the cargo
compartment.
Related information
•
Driving with a trailer (p. 472)
• Towing capacity and tongue weight (p. 660) Driving with a trailer
There are a number of things to consider when
towing a trailer, such as the towbar, the trailer
and how the load is distributed in the trailer.
Load-carrying capacity is determined by the vehi-
cle's curb weight. The total weight of all passen-
gers and any installed accessories, e.g. towbar,
reduces the vehicle's load-carrying capacity by
the corresponding amount.
• Towbars used on the vehicle must be
approved for the applicable use.
• Distribute the load on the trailer so that the
weight on the towbar complies with the
specified maximum towball weight. The
tongue weight is calculated as part of the
vehicle's payload.
• Increase the tire pressure to the recom-
mended pressure for a full load.
• The engine is subjected to more load than
usual when towing a trailer.
• Towing a trailer affects the vehicle's han-
dling, durability and driving economy.
• Do not drive with a heavy trailer when the
vehicle is very new. Wait until the mileage
has reached at least 1000 km (620 miles).
• On long and steep downgrades, the vehicle's
brakes are subjected to much more load
than usual. When manually shifting, down-
shift and adapt speed accordingly. •
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).

STARTING AND DRIVING
* Option/accessory.473
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.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. 474)
• Checking trailer lights (p. 475)
• Towing capacity and tongue weight (p. 660)
• Overheating of engine and transmission
(p. 468)

STARTING AND DRIVING
* Option/accessory.
474 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. When Trailer Stability Assist is
activated, the ESC symbol is
displayed in the instrument
panel.
Related information
•
Driving with a trailer (p. 472)
• Electronic Stability Control (p. 274) 8
Trailer Stability Assist
9 Electronic Stability Control