2020 VOLVO XC90 TWIN ENGINE stop start

STARTING AND DRIVING
* Option/accessory.
426
Hill Start Assist
The function for assisting when starting the vehicle on inclines (HSA 4
) helps prevent the
vehicle from rolling backward when starting on an uphill gradient. When backing up a hill,HSA helps prevent the vehicle from rollingforward.
The function retains pressure from the brake pedal in the brake system for several secondsafter the brake pedal has been released. This temporary braking effect is released after a few seconds or when the driver begins driv-ing. Hill Start Assist is available even when the Auto-hold brake function is switched off.
Related information
Auto-hold brakes (p. 424)
Brakes (p. 417)
Braking assist after a collision
In a collision in which the activation level is reached for the pyrotechnic seat belt tension-ers or airbags, or if a collision with a large ani-mal is detected, the vehicle's brakes will beautomatically activated. This function isintended to help prevent or reduce the effectsof any subsequent collision.
After a serious collision, it may no longer be possible to control and steer the vehicle. Inorder to avoid or mitigate a possible furthercollision with a vehicle or an object in the vehi-cle's path, the brake assist system is activatedautomatically to help stop the vehicle safely. If braking is not appropriate, e.g. if there is a risk of being hit by passing traffic, the drivercan override the system by depressing theaccelerator pedal. This function assumes that the brake system is intact after a collision.
Related information
Rear Collision Warning
* (p. 341)
BLIS
* (p. 342)
Brake functions (p. 417)
Transmission
The transmission is part of the vehicle's drive- line (power transmission) between the engineand the drive wheels. The function of thetransmission is to change gears dependingon speed and power needs.
The vehicle has an 8-speed automatic trans- mission and an electric motor for rear-wheeldrive. The number of gears allows the engine'storque and power band to be effectively uti-lized. Two of the gears are overdrive gears thatsave fuel when driving at a constant enginespeed. Manual shifting is also possible. Theinstrument panel shows the gear currently inuse.
Related information
Automatic transmission (p. 427)
4
Hill Start Assist

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Instrument panel when the paddles are activated for shifting.
Instrument panel when the paddles are activated for shifting in manual mode.
ChangeTo shift one gear:
–Pull one of the paddles toward the steer- ing wheel and then release.As long as the engine speed (rpm) is withinthe permissible range for the selected gear, agear shift will take place each time a paddle ispulled. After each gear shift, a number indicat-ing the current gear will be displayed in theinstrument panel.
Turning off Start/Stop
Manual deactivation in gear
D and B
–Deactivate the paddles by pulling the right paddle ( +) toward the steering wheel and
holding it until the number of the currentgear is no longer displayed in the instru-ment panel.
> The transmission will revert to gear D
or B depending on which gear was
selected before the paddles were acti- vated.
Automatic deactivation
In gear position D, the steering wheel paddles
are deactivated after a short period of time if they are not used. The number of the currentgear will no longer be displayed in the instru-ment panel. In gear position B, the paddles will not acti-
vate automatically.
Related information
Automatic transmission (p. 427)
Gear selector positions for automatic transmissions (p. 428)
Shiftlock The automatic transmission's shiftlock func- tion helps prevent inadvertently moving thegear selector between different positions.
Automatic shiftlockThe automatic shiftlock has a separate safety system.
From Park -
P
To move the gear selector from P to another
gear, the brake pedal must be depressed and the ignition in mode II.
From Neutral - N
If the gear selector is in N and the vehicle has
been stationary for at least 3 seconds (with or without the engine running), the gear selectorwill be locked in that position. To move the gear selector from N to another
gear, the brake pedal must be depressed and the ignition in mode II.
Messages in the instrument panelIf the gear selector is locked in position, amessage will appear in the instrument panel, e.g.
Gear lever Press brake pedal to
activate gear lever.
There is no mechanical shiftlock function.

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Drive systemsVolvo Twin Engine combines a combustion engine for the front wheels and an electricmotor for the rear wheels.
Two drive systemsDepending on the selected drive mode and power available in the electric motor, the drivesystems can either be used separately or intandem. The electric motor gets its energy from a hybrid battery located under the tunnel con-sole. The hybrid can be charged from a walloutlet or in a special charging station. Thecombustion engine can also charge the hybridbattery using a special high-voltage generator. Both the combustion engine and the electric motor can generate power directly to thewheels. An advanced control system coordi-nates both the drive systems to help optimizedriving economy.
Hybrid battery - The hybrid battery's func- tion is to store electrical current. Thisenergy is provided by plugging the charg-ing cable into an electrical outlet, throughregenerative braking or from the high-volt-age generator. This provides current topower the electric motor and to temporar-ily power the electrical air conditioning toprecondition the passenger compartment.
Combustion engine - The combustion engine starts when the charge level in thehybrid battery is too low to provide thepower output requested by the driver.
High-voltage generator 6
- Charges the
hybrid battery. Starter for the combustion engine. Can provide the combustion engine with extra electrical current.
Electric motor - Powers the vehicle using electricity. Can provide extra torque andpower during acceleration. Provides elec-trical all-wheel drive functionality. Regen-erates braking energy into electrical cur-rent.
Related information

General information about Twin Engine(p. 394)
Starting and stopping the combustionengine in Twin Engine vehicles (p. 433)
Drive modes (p. 433)
Transmission (p. 426)
Factors affecting electric motor range(p. 448)
6
CISG (Crank Integrated Starter Generator) – combined high-voltage generator and starter.

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* 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.

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441
Symbols and messages in driver display
Symbol Message Meaning
Suspension Deactivated by userActive chassis has been switched off manually by the user.
Suspension Temporarily reduced performanceActive chassis performance has been temporarily reduced due to extensive system use. If this message appears frequently (e.g. several times in one week) contact a workshopA
.
Suspension Service requiredA fault has occurred. Visit a workshop A
as soon as possible.
Suspension failure Stop safelyA critical fault has occurred. Stop safely, and have the car transported (raised with all wheels on the flatbed) to a workshop A
.

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* Option/accessory.443
Leveling control settings *
Turn off leveling control before lifting the vehicle with a jack to help avoid problemswith the pneumatic suspension. The vehicle can be lowered or raised to make it easier to load or for passengers to get inand out.
Adjusting loading mode
Use the buttons in the cargo compartment to raise or lower the rear section of the vehicle tofacilitate loading or unloading the vehicle orconnecting or disconnecting a trailer.
Center display settings
Easy Entry and Exit Suspension Control
The vehicle can be lowered to make it easier to get in and out. Activating easy entry in the center display: 1.
Tap
Settings in the Top view.
2. Tap
My CarMirrors and Convenience.
3. Select
Easy Entry and Exit Suspension
Control.
> When the vehicle is parked and the engine is turned off, the level is low- ered. (Level adjustment will stop if aside door is opened and will resumeafter a slight delay when the door hasbeen closed.) When the engine isstarted and the vehicle begins to move,the level will be raised to the height setby the selected drive mode.
Disable Leveling Control
In certain situations, this function must be turned off, e.g. before the vehicle is raised using a jack *. The level difference caused by
raising the vehicle with a jack could cause problems with the pneumatic suspension. Turning off the function in the center display:1. Tap
Settings in the Top view.
2. Tap
My CarParking Brake and
Suspension.
3. Select
Disable Leveling Control.
Related information
Leveling control
* and suspension (p. 440)
Loading recommendations (p. 585)
Low Speed Control
The low-speed function (LSC 10
) facilitates
and improves control and traction on rough roads and slippery surfaces, e.g. when towinga trailer on grass or up boat ramps. The function is included in the
Off Road drive
mode.
Low Speed Control is designed for driving on rough roads and when towing trailers at lowspeeds, up to approximately 40 km/h (25mph). When driving at low speeds, LSC prioritizes low gears and all-wheel drive to help avoidwheel spin and improve traction on all wheels.The accelerator pedal will be less responsiveto improve traction and speed control at lowspeeds. The function is activated together with Hill Descent Control (HDC 11
), which makes it pos-
sible to control speed going down steep hills using the accelerator pedal and reduces theneed to use the brake pedal. The systemmakes it possible to maintain a low and uni-form speed when driving down steep hills.

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

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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!