2017 VOLVO XC90 T8 engine

STARTING AND DRIVING
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Starting and driving The vehicle is equipped with features that sup- plement its basic functions, such as shifting gears with steering wheel paddles *.
The vehicle is equipped with an automatic trans- mission that also makes it possible to shift gearsmanually. Certain functions can also be used when the engine is not running, depending on the ignitionmode being used.
Related information
• Starting the engine (p. 390)
• Ignition modes (p. 389)
• Automatic transmission (p. 414)
• Opening/closing the fuel filler door (p. 380)
• Parking brake (p. 369)
Brakes The brake system is a hydraulic system consist- ing of two separate brake circuits. If a problemshould occur in one of these circuits, it is stillpossible to stop the vehicle with the other brakecircuit.
Brake systemIf one of the brake circuits is not functioning, more pressure will be needed on the brake pedal(and the pedal will go down farther) for normalbraking effect. If the brake pedal must be depressed farther than normal and requires greater foot pressure,the stopping distance will be longer. Pressure on the brake pedal is enhanced by the power braking function.
WARNING
If the vehicle does not have electrical current and both the electric motor and gasolineengine are switched off, the brakes cannot beused to stop the vehicle.
When the Hill Start Assist function is being used, it will take slightly longer for the brake pedal toreturn to its normal position if the vehicle isparked on an incline or uneven surface. When driving in very hilly areas or if the vehicle is carrying a heavy load, using brake mode B to
augment the brakes or the
Off Road* drive mode can also be used on steep downgrades to increase the engine braking effect at low speeds.
Anti-lock Braking System
ABS
The ABS system helps to improve vehicle control (stopping and steering) during severe brakingconditions by limiting brake lockup. When ABS is operating, there may be some vibration in the brake pedal, which is normal. The system performs a brief self-diagnostic test when the engine has been started and driverreleases the brake pedal. Another automatic testmay be performed when the vehicle first reachesa speed of approximately 6 mph (10 km/h). Thebrake pedal will pulsate several times and asound may be audible from the ABS controlmodule, which is normal.
Function check when the engine is
started
A Plug-in Hybrid is equipped with a "brake bywire" brake system. A function check is per-formed each time the engine is started and thedriver depresses the brake pedal to move the gear selector from P.
In certain cases, a message may appear in the instrument panel saying that pressure on thebrake pedal is too low. Press harder on the pedal.
Light braking charges the hybrid batteryWhen the brakes are applied lightly, the electricmotor's braking function is used, which converts

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kinetic energy into electricity that is used to charge the hybrid battery. This is indicated in theinstrument panel, see also the article "Generalinformation about Twin Engine Plug-in Hybridvehicles".
Battery charging gauge in the instrument panel
This function is active at speeds from approx. 90 mph (150 km/h) down to 3 mph (5 km/h).When braking at speeds outside of this range orduring harder braking, the hydraulic brake systemis used.
Cleaning the brake discsCoatings of dirt and water on the brake discsmay result in delayed brake function. This delay isminimized by cleaning the brake linings. Cleaning the brake pads is advisable in wet weather, prior to long-term parking, and after thevehicle has been washed. Do this by braking gen-tly for a short period while the vehicle is moving.
Driving on wet or salted roadsProlonged driving on wet or salted roads canaffect brake function and increase stopping dis-tance. Be sure to keep a safe distance to thevehicle ahead when driving under these condi-tions.
Brake pad inspection
On vehicles equipped with a jack
*, the condition
of the brake pads can be checked by raising thevehicle and performing a visual inspection of thebrake pads.
WARNING
• If the vehicle has been driven immediately prior to a brake pad inspection, the wheelhub, brake components, etc., will be veryhot. Allow time for these components tocool before carrying out the inspection.
• Apply the parking brake and put the gear selector in the Park (
P) position.
• Block the wheels standing on the ground, use rigid wooden blocks or large stones.
WARNING
•
Use the jack intended for the vehicle when changing a tire. For any other job,use stands to support the vehicle.
• The jack should be kept well-greased andclean, and should not be damaged.
• Be sure the jack is on a firm, level, non-slippery surface.
• No objects should be placed between thebase of jack and the ground, or betweenthe jack and the attachment bar on thevehicle.
• The jack must correctly engage the jackattachment.
• Never allow any part of your body to beextended under a vehicle supported by ajack.

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Instrument panel symbols
Symbol Explanation
A
BRed
symbol: Check the brake fluid
level. If the level is low, top up and have the system inspected todetermine the cause of the loss offluid. Yellow symbol: there is a fault in
the brake pedal sensor.
A
B Steady glow for more than 2 seconds: there is a fault in theABS system. The normal brakesystem will still function but with-out ABS brake modulation.
If Brake pedalCharacteristics
changed Service required is
displayed, the Brake-by-Wire sys- tem is not functioning properly.The brake pedal must be pressedfarther down and with more pres-sure for braking effect.
A US models
B Canadian models
WARNING
If both symbols illuminate at the same time and the brake level is below the MIN mark in
the reservoir or if a brake system-related mes-sage is shown in the instrument panel: DO
NOT DRIVE . Have the vehicle towed to a
trained and qualified Volvo service technician and have the brake system inspected. If both symbols illuminate at the same time and the brake level is normal (not below the
MIN mark in the reservoir) or if a brake sys-
tem-related message is shown in the instru- ment panel: drive the vehicle carefully to anauthorized Volvo workshop and have thebrake system inspected by a trained andqualified Volvo service technician.
Related information
• Brake functions (p. 364)
• Brake assist system (p. 365)
• Emergency brake lights (p. 366)
• General information about Twin Engine Plug- in Hybrid vehicles (p. 16)
Brake functions
The vehicle's standard braking features are aug- mented by a number of auxiliary help functions.
In addition to the wheel brakes and the parking brake, the vehicle is equipped with several auto-matic brake assist functions. These systems helpthe driver by e.g., keeping the vehicle stationarywhen the brake pedal is not depressed (at a traf-fic light or intersection), when starting up a hill orwhen driving down a hill. These systems include: • Auto-hold brakes
• Hill Start Assist
• Braking assist after a collision
• Hill Descent Control
*
Related information
•Brakes (p. 362)
• Parking brake (p. 369)
• Hill Descent Control (HDC) (p. 366)
• Auto-hold brake function (p. 365)

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Auto-hold brake function
With the Auto-hold brake function, the driver can release the brake pedal and the brakes willremain applied, for example, when the vehiclehas stopped at a traffic light or intersection.
When the vehicle is no longer moving forward, Auto-hold applies the brakes automatically, eitherusing the normal brakes or the parking brake.The brakes will be released when the acceleratorpedal is depressed. If the driver's door is opened or the engine is turned off, the parking brake will be applied auto-matically. Auto-hold is deactivated when the transmission is in neutral or if the driver's door is open and theseat belt is unbuckled.
Auto-hold control
Auto-hold control and indicator light
Turn Auto-hold on or off by pressing the control in the tunnel console. The indicator light illumi-nates when the function is on. When Auto-hold is off, Hill Start Assist (HSA) will be activated to help prevent the vehicle from roll-ing backwards when starting up a hill.
Instrument panel symbol
Symbol Explanation
The symbol in the instrument panel illuminates when this func-tion is using the normal brakes tokeep the vehicle stationary.
A
BThis symbol in the instrument panel illuminates when Auto-holdis using the parking brake to keepthe vehicle stationary
A
US models
B Canadian models
Related information
• Hill Start Assist (p. 368)
• Brake functions (p. 364)
Brake assist system The Brake Assist System (BAS) increases brak- ing force, thereby helping reduce braking dis-tance.
The system monitors the driver's braking habits and increases braking force when necessary.Brake force can be increased up to the point atwhich the ABS system is activated. The functionis deactivated when pressure on the brake pedaldecreases.
Related information
• Brakes (p. 362)

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Braking effect after a collisionIn certain types of collisions, the vehicle's brakes are applied to help prevent or mitigate a secon-dary collision.
Maintaining control of the vehicle after a collision may be difficult. To help avoid or mitigate theeffect of a secondary collision, the brakes areapplied automatically to help bring the vehicle toa stop. The brake lights and hazard warning flashers will be activated and the flashers will remain on afterthe vehicle has come to a standstill. The parkingbrake will then be applied automatically. In a situation where stopping the vehicle may not be desirable, the driver can override this systemby pressing the accelerator pedal. This feature can only function if the brake system is intact after the collision.
Related information
• Brake functions (p. 364)
• Airbag system (p. 69)
• Rear Collision Warning (RCW) (p. 324)
Emergency brake lights
The emergency brake lights activate in the event of hard braking/rapid deceleration at most nor-mal driving speeds or if the ABS system is acti-vated. This function causes an additional taillighton each side of the vehicle to illuminate to helpalert vehicles traveling behind.
Once the emergency brake lights have been acti- vated, if the driver releases the brake pedal, thebrake lights will return to their normal function.
Related information
• Brakes (p. 362)
• Hazard warning flashers (p. 150)
• Brake lights (p. 150)
Hill Descent Control (HDC) HDC is a type of low-speed automatic engine brake and makes it possible to increase ordecrease the vehicle's speed on steep downhillgradients using only the accelerator pedal, with-out applying the brakes. HDC is integrated into the
Off Road drive
mode.
HDC is particularly useful when driving down steep hills with rough surfaces, and where theroad may have slippery patches.
WARNING
HDC does not function in all situations, and is a supplementary braking aid. The driver hasfull responsibility for driving in a safe manner.
FunctionHDC allows the vehicle to roll forward or in reverse at very low speed with enhanced enginebraking. However, speed can be adjusted to ahigher level with the accelerator pedal. When theaccelerator pedal is released, the vehicle willreturn to very low speed regardless of the steep-ness of the hill and without applying the brakes.The brake lights illuminate when HDC is func-tioning. The driver can use the brakes to slow or stop the vehicle at any time.

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HDC is activated along with Low Speed Control (LSC), which together make driving on slipperysurfaces at low speeds easier. When HDC and LSC are activated, this changes the response from the accelerator pedal andengine.
Activating HDCThis function can be activated in different ways,depending on how the vehicle is equipped.
Select the Off Road drive mode to activate the
function. Select a different drive mode to turn HDC off. If this is done while the vehicle is on a steep down-grade, engine braking will decrease gradually.
Related information
• Brake functions (p. 364)
• Low Speed Control (LSC) (p. 367) •
Drive modes (p. 411)
Low Speed Control (LSC) Low Speed Control (LSC) helps make off-road driving easier on slippery surfaces when towinga trailer on grass, etc. This feature is part of the
Off Road drive mode.
When driving at low speeds, LSC prioritizes low gears and all wheel drive to help avoid wheelspin and to improve traction on slippery surfa-ces. The accelerator pedal and engine react dif-ferently to make low-speed driving easier.
LSC is activated along with the Off Road drive
mode. It is activated along with Hill Descent Control (HDC), which increases engine braking to helpkeep vehicle speed low and smooth, even drivingdown steep hills.

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Activating LSC
Select the Off Road drive mode to activate the
function. Select any other drive mode to turn it off.
NOTE
When LSC with HDC is activated by the Off
Road drive mode, the feel of the accelerator
pedal and engine response will change. The
Off Road drive mode is not intended to
be used on normal roads. The function is deactivated when driving at higher speeds and must be reactivated atlower speeds if so desired.
Related information
• Brake functions (p. 364)
• Hill Descent Control (HDC) (p. 366)
• Drive modes (p. 411)
Hill Start Assist
Hill Start Assist (HSA) helps prevent the vehicle from rolling backwards when starting up a hill. Ifyou are backing up a hill, HSA helps prevent thevehicle from rolling forward.
HSA makes it easier to start or back up on a hill by retaining pressure on the brake pedal for sev-eral seconds after the pedal has been released inorder to keep the vehicle at a standstill. The brakes will be released after several seconds or when the driver presses the accelerator pedal. HSA is available even if the Auto-hold braking function is turned off.
Related information
• Brake functions (p. 364)
• Auto-hold brake function (p. 365)

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Symbol in the instrument panel
SymbolExplanation
A
BThe symbol flashes while the park- ing brake is being applied. If the symbol flashes at any other time, this indicates a fault. See themessage in the instrument panel.
A
US models
B Canadian models
Automatic function
The parking brake is applied automatically:
• If the Auto Hold function is activated and the vehicle has been stationary for approx.5 minutes.
• If the gear selector is moved to
P on a steep
hill.
• When the engine is turned off (this functioncan be selected, see "Parking brake set-tings" below).
Emergency braking
In an emergency, the parking brake can be applied when the vehicle is moving by pressing and holding up the control. Braking will be inter-rupted when the control is released. An audible signal will sound during this proce- dure if the vehicle is moving at higher speeds.
Releasing the parking brake
Releasing manually
1. Press firmly on the brake pedal.
2. Press the control.
> This releases the parking brake and thesymbol in the instrument panel will go out.
Releasing automatically
1. The driver must fasten his/her seat belt.
2. Start the engine.
3. Press firmly on the brake pedal.4. Move the gear selector to D or R and press
the accelerator pedal.
> This releases the parking brake and the symbol in the instrument panel will go out.
NOTE
• For safety reasons, the parking brake is only released automatically if the engineis running and the driver is wearing a seatbelt.
• The electric parking brake will bereleased immediately when the accelera-tor pedal is pressed and the gear selector is in position
D or R.
Parking on a hillPut the gear selector in P.
• If the vehicle is pointing
uphill, turn the front
wheels so that they point away from the curb.
• If the vehicle is pointing
downhill, turn the
front wheels so that they point toward the curb.
The parking brake should also be applied.
WARNING
Always apply the parking brake when parking on hills or uneven surfaces.