2020 VOLVO XC90 TWIN ENGINE brakes

STARTING AND DRIVING
}}
* Option/accessory.433
Starting and stopping the combustion engine in Twin Enginevehicles An advanced control system determines the distance that the vehicle can be driven on thecombustion engine, electric motor, or both atthe same time. When driving on only theelectric motor, the vehicle may automaticallystart the combustion engine due to outsidecircumstances, e.g. low ambient tempera-tures. This is completely normal. The com-bustion engine will also always start whenthe hybrid battery is nearly fully discharged.
Climate settings at low temperaturesAt low ambient temperatures, the combustion engine will sometimes start automatically tohelp achieve the desired passenger compart-ment temperature and air quality. The amountof time the combustion engine is running canbe affected by lowering the temperature
reducing blower speed
activating
Pure drive mode.
Using the electric motor in hot or cold
weather
At very low or high ambient temperatures, the electric motor's driving range and power maybe reduced and affect how often the combus-tion engine automatically starts.
Emission control systemTo help ensure that the emission control sys-tem is as energy-efficient as possible, thecombustion engine will run for several minutesafter it is started. The amount of time the com-bustion engine needs to be used variesdepending on the temperature of the three-way catalytic converter.
WARNING
California Proposition 65 Operating, servicing and maintaining a pas- senger vehicle can expose you to chemi-cals including engine exhaust, carbon mon-oxide, phthalates, and lead, which areknown to the State of California to causecancer and birth defects or other reproduc-tive harm. To minimize exposure, avoidbreathing exhaust, do not idle the engineexcept as necessary, service your vehicle ina well ventilated area and wear gloves orwash your hands frequently when servicingyour vehicle. For more information go towww.P65Warnings.ca.gov/passenger-vehicle.
Related information
Drive systems (p. 432)
Economical driving (p. 446)
Drive modes (p. 433)
Drive modes
Drive modes affect the vehicle's driving cha- racteristics in different ways to enhance andsimplify the driving experience in certaintypes of situations.
Drive modes enable easy access to the vehi- cle's many functions and settings in differentdriving situations. Each drive mode is adaptedto help optimize driving characteristics. Steering
Engine/transmission/all-wheel drive
Brakes
Pneumatic suspension
* and shock absorb-
ers
Instrument panel
Climate control settings
Select the drive mode that is adapted to the current driving conditions. Keep in mind thatnot all drive modes are available in all situa-tions.

STARTING AND DRIVING
445
Hill Descent Control
The function for assisting when driving down- hill (HDC 12
) is a low-speed function with
increased engine braking. The function makes it possible to increase or decrease thevehicle's speed on steep downhill gradientsby only using the accelerator pedal, withoutapplying 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 slip-pery or otherwise difficult road surfaces. Thedriver does not need to use the brake pedalbut can instead focus on steering.
WARNING
HDC is only intended to be a supplemen- tary braking aid and it does not function inall situations. 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 speedsassisted by the brake system. The driver canincrease the speed by pressing the acceleratorpedal. When the accelerator pedal is released, the vehicle will return to very low speedregardless of how steep the hill is and withoutthe brakes needing to be applied. The brakelights will illuminate when the function is acti-vated. The driver can brake to stop or slow the vehi- cle at any time by depressing the brake pedal. HDC is activated along with Low Speed Con- trol (LSC
13
), which facilitates and improves
traction and control on rough and slippery sur- faces. The system is intended to be used atlow speeds, up to approximately 40 km/h (25mph).
To keep in mind when using HDC
If the function is switched off while drivingon a steep downhill gradient, brakingeffect 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 thirdgear or higher when HDC is active.
NOTE
When LSC with HDC is activated in theOff Road drive mode, the feel of the accel-
erator 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 atlower speeds if so desired.
Related information
Activating and deactivating Hill Descent Control using the function button (p. 446)
Changing drive mode (p. 438)
Low Speed Control (p. 443)
All Wheel Drive (AWD) (p. 431)
12
Hill Descent Control
13 Low Speed Control

STARTING AND DRIVING
* Option/accessory.447
Preconditioning
Whenever possible, precondition the vehi- cle before driving by connecting thecharging cable to an electrical outlet.
Avoid parking the vehicle somewherewhere the interior will become too hot ortoo cold while the vehicle is parked. If pos-sible, park the vehicle in a climate-con-trolled garage.
During a short drive after passenger com-partment preconditioning, turn off thepassenger compartment fan or the airconditioning in a hot climate.
If preconditioning is not possible when itis cold outside, use seat and steeringwheel heating first. Avoid heating theentire passenger compartment to reducethe amount of current being taken fromthe hybrid battery.
Driving

Choose the Pure drive mode to help mini-
mize electric power consumption.
Maintain a steady speed and a generous following distance to traffic ahead to mini-mize braking. This drive mode has thelowest power consumption.
Balance energy requirements using theaccelerator pedal. Use the indicator on theinstrument panel to see available electricpower and avoid starting the combustion engine unnecessarily. The electric motor is more effective than the combustion engine, especially at low speeds.
When braking is necessary, brake gentlyusing the brake pedal. This will helprecharge the hybrid battery. A regenerativefunction is integrated in the brake pedaland can be augmented by the electricmotor's braking capacity when the gearselector is in mode
B.
Higher speeds increase energy consump-tion - air resistance increases with speed.
Activate the
Hold function in the Function
view at high speeds when traveling farther than is possible using the hybrid battery'scapacity.
Whenever possible, avoid using the
Charge function to charge the hybrid bat-
tery. Charging the battery using the com- bustion engine increases fuel consump-tion and carbon dioxide emissions.
In a cold climate, reduce heating of thewindshield/rear window, mirrors, seatsand the steering wheel.
Maintain the correct pressure in the tiresand check pressure regularly.
The type of tires used could affect energyconsumption - consult a retailer for adviceon suitable tires.
Remove unnecessary items from the vehi-cle - the heavier the load, the higher thefuel consumption.
Roof loads increase air resistance andincrease fuel consumption. Remove roofboxes, ski racks, etc. that are not in use.
Avoid driving with the windows open.
Do not keep the vehicle still on an upwardgradient by using the accelerator pedal.Use the brakes instead.
Related information
Drive-E
‒ purer driving pleasure (p. 30)
Energy distribution in hybrid mode using map data
* (p. 439)
Factors affecting electric motor range (p. 448)
Hybrid gauge (p. 89)
Checking tire pressure (p. 553)

STARTING AND DRIVING
}}
451
Slippery driving conditionsTo help optimize traction and roadholding, Volvo recommends using snow tires on allwheels whenever there is a risk of snow or iceon the road.
NOTE
Certain countries require use of winter tires by law. Not all countries permit the use ofstudded tires.
Practice driving on slippery surfaces under controlled conditions to learn how the vehiclereacts.
Related information
Snow tires (p. 567)
Snow chains (p. 567)
Braking on salted roads (p. 420)
Braking on wet roads (p. 420)
Filling washer fluid (p. 656)
Start battery (p. 613)
Replacing windshield wiper blades(p. 654)
Changing rear window wipers (p. 653)
Refilling coolant (p. 610)
Driving through standing water
It may be necessary to drive the vehicle through standing water, e.g. deep puddles orflooding on the road. This must be done withgreat caution.
To help prevent damage to the vehicle when driving through water:
Do not drive in water higher than the floorof the vehicle. If possible, check the depthof the water at its deepest point beforedriving through it. Be particularly carefulwhen driving through flowing water.
Always select the
Off Road drive mode
before driving in water to ensure the gaso- line engine is running.
Do not drive faster than walking speed.
Do not stop the vehicle in the water. Drivecarefully forward or back the vehicle out ofthe water.
Remember that waves created by passingvehicles could cause the water level to riseabove the vehicle's floor level.
Avoid driving through salt water to helpavoid the risk of corrosion.
CAUTION
Parts of the vehicle (e.g. engine, transmis- sion, driveline, electrical components, etc.)can be damaged if the vehicle is driventhrough water higher than its floor level.Damage to any components caused byflooding, vapor lock or insufficient oil is notcovered under warranty. If the engine stalls while the vehicle is in water, do not attempt to restart it. Havethe vehicle towed on the bed of a towtruck to a workshop - an authorized Volvoworkshop is recommended.
CAUTION
Because it can be difficult to determine the water depth, Volvo recommends not driv-ing through standing or running water. Thedriver is always responsible for operatingthe vehicle in a safe manner and adheringto all applicable laws and regulations.
When you have passed the water, press lightly on the brake pedal and check that the brakesare 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 cou- pling contact, clean the contact after driving inwater or mud.

STARTING AND DRIVING
}}
* Option/accessory.465
Driving with a trailer
There are a number of things to consider when towing a trailer, such as the towbar, thetrailer and how the load is distributed in thetrailer.
Load-carrying capacity is determined by the vehicle's curb weight. The total weight of allpassengers and any installed accessories, e.g.towbar, reduces the vehicle's load-carryingcapacity by the corresponding amount.
Towbars used on the vehicle must beapproved for the applicable use.
Distribute the load on the trailer so thatthe weight on the towbar complies withthe specified maximum towball weight.The tongue weight is calculated as part ofthe vehicle's payload.
Increase the tire pressure to the recom-mended pressure for a full load.
The engine is subjected to more load thanusual 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 thevehicle is very new. Wait until the mileagehas reached at least 1000 km (620 miles).
On long and steep downgrades, the vehi-cle's brakes are subjected to much moreload than usual. When manually shifting, downshift and adapt speed accordingly.
Follow applicable regulations regarding permitted speed and weight.
Drive slowly when towing a trailer up along and steep incline.
The maximum trailer weights given onlyapply to altitudes up to 1000 meters(3280 feet) above sea level. At higher alti-tudes, engine power (and thus the vehi-cle's climbing ability) is decreased due tothe reduced air density, and the maximumtrailer weight must therefore be reduced.The weight of the vehicle and trailer mustbe decreased by 10% for each additional1000 m (3280 feet) or part thereof.
Avoid driving with a trailer on inclines ofmore than 12%.
Avoid overloading and other incorrect use.
The trailer's brakes must be balanced withthe vehicle's brakes to help ensure safestops (follow applicable local regulations).
NOTE
To facilitate towing a trailer in a vehicle equipped with pneumatic suspension
*,
select: the
Suspension ControlDynamic setting in Individual drive mode.
CAUTION
Bumper-attached trailer hitches must not be used on Volvos, nor shouldsafety chains be attached to thebumper.
Trailer hitches attaching to the vehiclerear axle must not be used.
Never connect a trailer's hydraulicbrake system directly to the vehiclebrake system, nor a trailer's lightingsystem directly to the vehicle lightingsystem. Consult your nearest author-ized Volvo retailer for correct installa-tion.
When towing a trailer, the trailer'ssafety chains or wire must be correctlyfastened to the attachment points pro-vided in the trailer hitch on the vehicle.The safety chain or wire must never befastened to or wound around the tow-ing ball.
NOTE
The optional detachable trailer hitch may not be available in all markets or on allmodels. Consult your Volvo retailer.

STARTING AND DRIVING
* Option/accessory.467
Trailer Stability Assist *
Trailer Stability Assist (TSA 16
) is a function
designed to help stabilize a vehicle that is towing a trailer when the vehicle and trailerhave begun to sway. The function is part of the Electronic Stability Control system ESC 17
.
Reasons for swayingA vehicle towing a trailer may begin to sway for various reasons. Normally this only occursat high speeds. However, if the trailer is over-loaded or unevenly distributed, e.g. too farback, there is a risk of swaying even at lowspeeds. 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 anuneven road or over a bump.
Sudden movements of the steering wheel.
Once swaying has begun, it can be difficult orimpossible to stop it. This makes the vehicleand trailer difficult to control and there is a riskof swerving into oncoming traffic or driving offthe road.
Trailer Stability Assist functionTrailer Stability Assist continuously monitorsthe vehicle's movements, particularly lateral movements. If swaying is detected, the brakesare applied individually on the front wheels,which has a stabilizing effect on the vehicleand trailer. This is often enough to enable thedriver to regain control of the vehicle. If the Trailer Stability Assist function's first attempt is not adequate to stop the swayingmotion, the brakes are applied on all wheelsand engine power is temporarily reduced. Asthe swaying motion begins to decrease andthe vehicle and trailer have once againbecome stable, TSA stops regulating thebrakes/engine power and the driver regainscontrol of the vehicle.
NOTE
Trailer Stability Assist is deactivated if the driver selects the sport mode by deactivat- ing
ESC in the center display's menu sys-
tem.
Trailer Stability Assist may not intervene if the driver tries to compensate for the swayingmotion by moving the steering wheel rapidly,because the system will then not be able todetermine if it is the trailer or the driver caus-ing the swaying. When Trailer Stability Assistis activated, the ESC symbolis displayed in the instrumentpanel.
Related information

Driving with a trailer (p. 465)
Electronic Stability Control (p. 281)
16
Trailer Stability Assist
17 Electronic Stability Control

||
WHEELS AND TIRES
568
CAUTION
Snow chains can be used on the vehicle, with the following restrictions:
Always follow the manufacturer'sinstallation instructions carefully. Installchains as tightly as possible andretighten periodically.
Only put snow chains on the frontwheels (also applies to all-wheel drivevehicles).
If accessory, aftermarket or "custom"tires and wheels with different dimen-sions than the original tires and wheelsare used, snow chains in some casesmay NOT be used. Sufficient distancebetween the chains and brakes, sus-pension and body components mustbe maintained.
Check local regulations regarding theuse of snow chains before installing.
Never exceed the snow chain manu-facturer's specified maximum speedlimit. Under no circumstances shouldyou exceed 50 km/h (30 mph).
Avoid bumps, holes or sharp turnswhen driving with snow chains.
Avoid driving on surfaces withoutsnow as this wears out both the snowchains and the tires.
The handling of the vehicle can be adversely affected when driving withchains. Avoid fast or sharp turns aswell as locked wheel braking.
Some types of strap-on chains affectbrake components and therefore mustNOT be used.
Consult a Volvo retailer for more information about snow chains.
Related information
Winter driving (p. 450)
Tire sealing system 15
The temporary tire sealing system can be used to seal a puncture in a tire or to checkand adjust the pressure in the tire. Models equipped with a spare wheel 16
do not
have the tire sealing system.
WARNING
California Proposition 65 Operating, servicing and maintaining a pas- senger vehicle can expose you to chemi-cals including engine exhaust, carbon mon-oxide, phthalates, and lead, which areknown to the State of California to causecancer and birth defects or other reproduc-tive harm. To minimize exposure, avoidbreathing exhaust, do not idle the engineexcept as necessary, service your vehicle ina well ventilated area and wear gloves orwash your hands frequently when servicingyour vehicle. For more information go towww.P65Warnings.ca.gov/passenger-vehicle.
The tire sealing system consists of a compres- sor and a bottle containing sealing compound.The sealing functions as a temporary repair.

MAINTENANCE AND SERVICE
}}
* Option/accessory.647
Automatic car washes
The vehicle should be washed as soon as it becomes dirty. The longer the dirt remains,the more difficult it will be to keep the vehicleclean. It could also lead to paint damage.
Washing your vehicle in an automatic car wash is a fast and easy way to keep your vehi-cle clean, but it does not reach all areas of thevehicle. Volvo recommends washing yourvehicle by hand or supplementing automaticcar washes with a hand wash.
NOTE
Volvo recommends not washing the vehi- cle in an automatic car wash during thefirst few months; the paintwork on newvehicles takes some time to fully harden.
CAUTION
Before driving the vehicle into a car wash, deactivate the Automatic Braking whenStationary and Automatic Parking BrakeApplication functions. If the functions arenot deactivated, the brake system willseize when the vehicle is stationary and thevehicle will not be able to roll.
CAUTION
For automatic car washes in which the vehicle is pulled forward on rolling wheels:
1. Before washing the vehicle, make sure that the automatic rain sensor is deac- tivated. If it is not deactivated andinadvertently starts, the wiper armscould be damaged.
2. To help prevent damage from the auto- matic car wash machinery, make surethat the door mirrors are folded in,antennas retracted or removed, andany auxiliary lights secured.
3. Drive into the automatic car wash.
4. Turn off the "Automatic Braking when Stationary" function using the
but-
ton in the tunnel console.
5. Turn off the "Automatic Parking Brake Application" function in the center dis- play's Top view.
6. Turn off the engine by turning the start knob in the tunnel console clockwise.Hold the knob in position for at least2 seconds.
The vehicle is now ready for the automaticcar wash.
CAUTION
The system will automatically change to P
mode if the above steps are not followed. In P mode, the wheels are locked, which
they should not be when the vehicle isbeing washed in a car wash.
NOTE
Keep in mind that if the vehicle is equipped with the keyless locking and unlocking function *, the doors and tailgate/trunk lid
may open when washing the vehicle if the remote key is within range.
Related information
Cleaning the exterior (p. 644)
Polishing and waxing (p. 644)
Hand washing (p. 645)
High-pressure washing (p. 648)
Cleaning the wiper blades (p. 648)
Cleaning exterior plastic, rubber and trim components (p. 649)
Cleaning rims (p. 650)
Corrosion protection (p. 650)
Auto-hold brakes (p. 424)