2020 VOLVO XC90 TWIN ENGINE control

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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

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Activating and deactivating Hill Descent Control using the functionbutton There is a function button for assistance on steep gradients with
Hill Descent Control in
the center display's Function view if the vehi- cle is not equipped with a drive mode controlin the tunnel console.
Selecting Hill Descent Control in the center display's Function view
HDC only works at low speeds.
–Tap the Hill Descent Control button to
activate or deactivate the function.
> An indicator light in the button will illu- minate when the function is activated.
When the engine is switched off, the function will be automatically deactivated.
NOTE
The function is deactivated when driving at high speeds and must be reactivated atlower speeds if so desired.
Related information
Hill Descent Control (p. 445)
Changing drive mode (p. 438)
Economical driving
Drive economically and more environmentally conscious by thinking ahead and avoidingrapid starts and stops.
Adapt your driving style and speed to the cur- rent traffic conditions. To help achieve the greatest distance with the lowest fuel consumption with Twin Engine,observe the following:
Charge
Charge the vehicle regularly by plugging it into an electrical outlet. Make it a habit toalways begin trips with the hybrid batteryfully charged.
Locate charging stations along your route.
If possible, choose parking spots withcharging stations.
NOTE
Charge the vehicle from the electricity grid as often as possible!

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Factors affecting electric motor rangeA number of factors affect the electric motor's driving range. The ability to achieve along driving range varies according to theoutside conditions and to how the vehicle isdriven.
The certified value for the distance that can be driven using the electric motor should not beconsidered an expected driving range. Theactual range is dependent on a number of fac-tors.
Factors affecting driving rangeThe driver can influence some factors affectingdriving range, but not all. The longest range is achieved under very favorable conditions when all factors positivelyinfluence range.
Factors the driver cannot control
There are several outside conditions that affect range to varying degrees:
the current traffic situation
driving short distances
topography
ambient temperature and headwinds
road conditions and road surface.
The table shows the approximate relationshipbetween ambient temperature and driving range with normal climate settings and withclimate settings turned off. Up to a certain limit, warmer ambient temper- atures increase the electric motor's drivingrange.
Ambient temperature
Climatesettingsturned offNormalclimatesettings
30 °C (86 °F) 95 % 80 %
20 °C (68 °F) 100 % 90%
10 °C (50 °F) 90 % 80 %
0 °C (32 °F) 80 % 60 %
-10 °C (14 °F) 70 % 40 %
Factors the driver can control
The driver should be aware that the following factors help conserve energy and improvedriving range: charging the battery regularly
preconditioning

Pure drive mode
climate control settings
speed and acceleration
the
Hold function
tires and tire pressure. The table shows the approximate relationship between constant speed and driving range.Driving at a lower constant speed helpsincrease the electric motor's driving range.
Constant speed
100 km/h (62 mph) 50 %80 km/h (50 mph) 70 %60 km/h (37 mph) 90 %
50 km/h (31 mph) 100 %
NOTE
The values shown in the table refer to a new vehicle.
None of the values are absolute, butare instead affected by e.g. drivingstyle, environment and other condi-tions.
Related information

Economical driving (p. 446)
Hold and Charge functions (p. 449)
Drive modes (p. 433)

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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.

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Related information
Recovery (p. 470)
Low Speed Control (p. 443)
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 instru-ment panel indicates the sideof the vehicle on which thefuel filler door is located.
1. Press the button on the dashboard.
> Pressure equalization in the fuel tankcauses a slight delay before the fuel filler door opens. The message
Preparing for refuel Fuel lid will be
unlocked when ready will appear in
the instrument panel. When the system is ready, the message
Fuel tank Ready
for refueling will be shown. If the gas-
oline engine is activated when the but- ton is pressed, it will usually be deacti-vated and the vehicle will switch toelectric propulsion.

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4544. Avoid overfilling the tank. Do not press the
handle on the filler nozzle again after it has initially stopped pumping.
> The fuel tank is now filled.
NOTE
An over-full tank may overflow in hot weather.
CAUTION
Avoid spilling gasoline during refueling. In addition to causing damage to the environ-ment, gasolines containing alcohol cancause damage to painted surfaces, whichmay not be covered under the New VehicleLimited Warranty.
Refueling from a fuel containerWhen filling from a fuel container, use the fun- nel provided in a foam block under the floorhatch in the cargo compartment.
1. Open the fuel filler door.
2. Insert the funnel into the fuel filler pipe'sopening. There are two flaps just inside the fuel filler pipe and the tube section ofthe funnel must push both of these flapsopen before fuel can be added.
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
Opening/closing the fuel filler door (p. 452)
Fuel (p. 454)
Fuel
Volvo recommends the use of detergent gas- oline to control engine deposits.
Deposit control gasoline (gasoline with detergent additives)
Detergent gasoline is effective in keeping injectors and intake valves clean. Consistentuse of deposit control gasolines will helpensure good driveability and fuel economy. Ifyou are not sure whether the gasoline containsdeposit control additives, check with the serv-ice station operator.
NOTE
Volvo recommends not using external fuel injector cleaning systems, e.g. do not adddetergent additives to gasoline before orafter refueling.
Unleaded fuelAll Volvo vehicles have a three-way catalytic converter and must only use unleaded gaso-line. US and Canadian regulations require thatpumps delivering unleaded gasoline arelabeled "UNLEADED". Only the nozzles ofthese pumps will fit in your vehicle's fuel fillerinlet. It is unlawful to dispense leaded fuel intoa vehicle labeled "unleaded gasoline only".Leaded gasoline damages the three-way cata-lytic converter and the heated oxygen sensor

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system. Repeated use of leaded gasoline will lessen the effectiveness of the emission con-trol system and could result in loss of emissionwarranty coverage. State and local vehicleinspection programs will make detection ofmisfueling easier, possibly resulting in emis-sion test failure for misfueled vehicles.
NOTE
Some U.S. and Canadian gasolines contain an octane enhancing additive calledmethyl-cyclopentadienyl manganese tricar-bonyl (MMT). If such fuels are used, yourEmission Control System performancemay be affected, and the Check EngineLight (malfunction indicator light) locatedon your instrument panel may light. If thisoccurs, please return your vehicle to atrained and qualified Volvo service techni-cian for service.
Gasoline containing alcohol and ethers, "Oxygenated fuels"
Some fuel suppliers sell gasoline containing "oxygenates" which are usually alcohols orethers. In some areas, state or local lawsrequire that the service pump be marked indi-cating use of alcohols or ethers. However,there are areas in which the pumps areunmarked. If you are not sure whether there isalcohol or ethers in the gasoline you buy,check with the service station operator. To
meet seasonal air quality standards, someareas require the use of "oxygenated" fuel. Volvo permits the use of the following "oxy- genated" fuels. However, the specified octaneratings must still be met.
Alcohol - Ethanol
Fuels containing up to 10% ethanol by volume may be used. Ethanol may also be referred toas Ethyl alcohol, or "Gasohol". Ethers - MTBE/ETBE: Fuels containing up to 22% MTBE/ETBE by volume may be used.
MethanolDo not use gasolines containing methanol(methyl alcohol, wood alcohol). This practicecan result in vehicle performance deteriorationand can damage critical parts in the fuel sys-tem. Such damage may not be covered underthe New Vehicle Limited Warranty.
Related information

Octane rating (p. 455)
Opening/closing the fuel filler door(p. 452)
Refueling (p. 453)
Emission controls (p. 457)
Octane rating Volvo requires premium fuel (91 octane 14
or
higher) for all T5, T6 and T8 engines, and rec- ommends AKI 93 for optimal performanceand fuel economy. See decal examples inillustrations 1 and 2.

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Minimum octane
Decals
Illustration 1: Sample fuel pump octane label14
.
Illustration 2: Decal on the inside of the fuel filler flap on vehicles that require premium fuel 15
.
TOP TIER Detergent GasolineVolvo endorses the use of "TOP TIER Deter- gent Gasoline" where available to help main-tain engine performance and reliability. TOPTIER Detergent Gasoline meets a new stand-ard jointly established by leading automotivemanufactures to meet the needs of today'sadvanced engines. Qualifying gasoline retail-ers (stations) will, in most cases, identify theirgasoline as having met the "TOP TIER Deter-gent Gasoline" standards.
NOTE
Information about TOP TIER Detergent Gasoline is available atwww.toptiergas.com.
NOTE
When switching to higher octane fuel or changing gasoline brands, it may be neces-sary to fill the tank more than once before adifference in engine operation is noticea-ble.
Fuel FormulationsDo not use gasoline that contains lead or man- ganese as a knock inhibitor, and do not use lead additives. Besides damaging the exhaust emission control systems on your vehicle, leadhas been strongly linked to certain forms ofcancer. Many fuels contain benzene as a solvent. Unburned benzene has been strongly linked tocertain forms of cancer. If you live in an areawhere you must fill your own gas tank, takeprecautions. These may include:
standing upwind away from the filler noz-zle while refueling
refueling only at gas stations with vaporrecovery systems that fully seal the mouthof the filler neck during refueling
wearing neoprene gloves while handling afuel filler nozzle.
Use of AdditivesWith the exception of gas line antifreeze dur-ing winter months, do not add solvents, thick-eners, or other store-bought additives to yourvehicle's fuel, cooling, or lubricating systems.Overuse may damage your engine, and someof these additives contain organically volatilechemicals. Do not needlessly expose yourselfto these chemicals.
14
AKI (Anti Knock Index) is an average value of RON (Research Octane Number) and MON (Motor Octane Number) - (RON)+(MON)/2
15 For supplementary information - see the car's Service and Warranty Booklet.