2019 VOLVO XC90 TWIN ENGINE warning

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)

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476
WARNING
California Proposition 65
Operating, servicing and maintaining a pas-
senger vehicle can expose you to chemicals
including engine exhaust, carbon monoxide,
phthalates, and lead, which are known to the
State of California to cause cancer and birth
defects or other reproductive harm. To mini-
mize exposure, avoid breathing exhaust, do
not idle the engine except as necessary, serv-
ice your vehicle in a well ventilated area and
wear gloves or wash your hands frequently
when servicing your vehicle. For more infor-
mation go to www.P65Warnings.ca.gov/
passenger-vehicle.
Related information

Opening/closing the fuel filler door (p. 474)
Fuel (p. 476) Fuel
Volvo recommends the use of detergent gaso-
line to control engine deposits.
Deposit control gasoline (gasoline with
detergent additives)
Detergent gasoline is effective in keeping injec-
tors and intake valves clean. Consistent use of
deposit control gasolines will help ensure good
driveability and fuel economy. If you are not sure
whether the gasoline contains deposit control
additives, check with the service station operator.
NOTE Volvo recommends not using external fuel
injector cleaning systems, e.g. do not add
detergent additives to gasoline before or after
refueling.
Unleaded fuelAll Volvo vehicles have a three-way catalytic con-
verter and must only use unleaded gasoline. US
and Canadian regulations require that pumps
delivering unleaded gasoline are labeled
"UNLEADED". Only the nozzles of these pumps
will fit in your vehicle's fuel filler inlet. It is unlaw-
ful to dispense leaded fuel into a vehicle labeled
"unleaded gasoline only". Leaded gasoline dam-
ages the three-way catalytic converter and the
heated oxygen sensor system. Repeated use of
leaded gasoline will lessen the effectiveness ofthe emission control system and could result in
loss of emission warranty coverage. State and
local vehicle inspection programs will make
detection of misfueling easier, possibly resulting
in emission test failure for misfueled vehicles.
NOTE
Some U.S. and Canadian gasolines contain an
octane enhancing additive called methyl-
cyclopentadienyl manganese tricarbonyl
(MMT). If such fuels are used, your Emission
Control System performance may be affected,
and the Check Engine Light (malfunction
indicator light) located on your instrument
panel may light. If this occurs, please return
your vehicle to a trained and qualified Volvo
service technician for service.
Gasoline containing alcohol and ethers,
"Oxygenated fuels"
Some fuel suppliers sell gasoline containing
"oxygenates" which are usually alcohols or
ethers. In some areas, state or local laws require
that the service pump be marked indicating use
of alcohols or ethers. However, there are areas in
which the pumps are unmarked. If you are not
sure whether there is alcohol or ethers in the
gasoline you buy, check with the service station
operator. To meet seasonal air quality standards,
some areas require the use of "oxygenated" fuel.

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478
NOTE
When switching to higher octane fuel or
changing gasoline brands, it may be neces-
sary to fill the tank more than once before a
difference in engine operation is noticeable.
Fuel FormulationsDo not use gasoline that contains lead or manga-
nese as a knock inhibitor, and do not use lead
additives. Besides damaging the exhaust emis-
sion control systems on your vehicle, lead has
been strongly linked to certain forms of cancer.
Many fuels contain benzene as a solvent.
Unburned benzene has been strongly linked to
certain forms of cancer. If you live in an area
where you must fill your own gas tank, take pre-
cautions. These may include:

standing upwind away from the filler nozzle
while refueling
refueling only at gas stations with vapor
recovery systems that fully seal the mouth of
the filler neck during refueling
wearing neoprene gloves while handling a
fuel filler nozzle.
Use of AdditivesWith the exception of gas line antifreeze during
winter months, do not add solvents, thickeners, or other store-bought additives to your vehicle's
fuel, cooling, or lubricating systems. Overuse may
damage your engine, and some of these additives
contain organically volatile chemicals. Do not
needlessly expose yourself to these chemicals.
WARNING Never carry a cell phone that is switched on
while refueling your vehicle. If the phone rings,
this may cause a spark that could ignite gaso-
line fumes, resulting in fire and injury.
WARNING
Carbon 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, such as when
towing a trailer or driving in hot weather or for
prolonged periods at high altitudes, it may be a
good idea to switch to a higher-octane fuel (AKI
6
91 or higher) or to switch to another brand of
gasoline in order to fully utilize the vehicle's
engine capacity and optimize traction.
Related information
Fuel (p. 476)
Emission controls (p. 479) 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
}}
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
* Option/accessory.
482 12. Remove the jumper cables in the reverse
order ‒ first the black cables and then the
red cables.
Make sure that none of the clamps of the
black jumper cables come into contact with
either vehicle's positive (+) jump start termi-
nals or either of the red jumper cable's con-
nected clamps.
WARNING PROPOSITION 65 WARNING! Battery posts,
terminals, and related accessories contain
lead and lead compounds, chemicals known
to the state of California to cause cancer and
reproductive harm. Wash hands after han-
dling.
WARNING
Batteries generate hydrogen gas, which
is flammable and explosive.
Do not connect the jumper cable to any
part of the fuel system or to any moving
parts. Avoid touching hot manifolds.
Battery fluid contains sulfuric acid. Do not
allow battery fluid to contact eyes, skin,
fabrics or painted surfaces.
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. 434)
Ignition modes (p. 437)
Adjusting the steering wheel (p. 201)
Selecting ignition mode (p. 438) 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

STARTING AND DRIVING
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483
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.
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. 483)
Towing capacity and tongue weight (p. 670) 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.

||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
487
Disabling the automatic check
The automatic light check can be disabled in the
center display.
1.Tap Settings in the Top view.
2.

Tap My Car Lights and Lighting
.
3. Deselect Automatic Trailer Lamp Check.
Manual check
If the automatic check has been disabled, the
check can be started manually.
1.
Tap Settings in the Top view.
2.

Tap My Car Lights and Lighting
.
3. Select Manual Trailer Lamp Check.
>

The light check will begin. Get out of the
vehicle to perform the check.
Related information
Driving with a trailer (p. 483) Towing using a towline
This section refers to one vehicle being towed
behind another using a towline.
Twin Engine vehicles may not be towed behind
another vehicle due to the risk of damage to the
electric motor. The vehicle must be lifted onto a
tow truck and transported with all four wheels on
the bed or lifting platform of the truck (no wheels
may touch the road).
Towing another vehicleTowing another vehicle requires a lot of power -
use the AWD drive mode. This helps charge the
hybrid battery and improve the vehicle's driving
and roadholding characteristics.
Before towing another vehicle, check applicable
speed limit regulations.
Jump startingDo not tow the vehicle to start the engine. Use an
auxiliary battery if the start battery's charge level
is so low that the engine cannot be started.
CAUTION Attempts to tow-start the vehicle could cause
damage to the electrical drive motor and
three-way catalytic converter.
Related information

Attaching and removing the towing eyelet
(p. 488)
Hazard warning flashers (p. 161)
Recovery (p. 489)
Jump starting using another battery (p. 481)
Selecting ignition mode (p. 438)