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DRIVER SUPPORT
* Option/accessory, for more information, see Introduction.343
Symbols and messages
SymbolMessageExplanation
Driver support system Reduced functionality Service requiredThe system is not functioning properly. Contact a trained and qualified Volvo service techni- cian.
Windscreen sensor Sensor blocked, see Owner's manualThe camera's functionality is limited.
Lane Keeping Aid Apply steeringLKA's steering assistance does not function if the driver's hands are not on the steering wheel. Steer the vehicle actively.
Related information
•Driving lane assistance (p. 338)
• Activating/deactivating Lane Departure Warning (LDW) (p. 340)
• Activating/deactivating Lane Keeping Aid (LKA)
* (p. 340)
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S T A R T I N G A N D D R I V I N G
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STARTING AND DRIVING
* Option/accessory, for more information, see Introduction.
346
Starting and driving
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. 372)
• Ignition modes (p. 370)
• Automatic transmission (p. 395)
• Opening/closing the fuel filler door (p. 363)
• Parking brake (p. 352)
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 vehicle does not have electrical current and both the electric motor and gasoline engineare switched off, the brakes cannot be usedto 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 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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STARTING AND DRIVING
}}
* Option/accessory, for more information, see Introduction.347
kinetic energy into electricity that is used to charge the hybrid battery. This is indicated in theinstrument panel, see also the article "Generalinformation about the XC90 T8 Twin EnginePlug-in Hybrid".
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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STARTING AND DRIVING
* Option/accessory, for more information, see Introduction.
348
Instrument panel symbols
SymbolExplanation
A
B
Red 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. 348)
• Brake assist system (p. 349)
• Emergency brake lights (p. 350)
• General information about the XC90 T8 Twin Engine Plug-in Hybrid (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. 346)
• Parking brake (p. 352)
• Hill Descent Control (HDC) (p. 350)
• Auto-hold brake function (p. 349)
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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 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) willbe activated to help prevent the vehicle from roll-ing backwards when starting up a hill.
Instrument panel symbol
SymbolExplanation
The symbol in the instrument panel illuminates when this func-tion is using the normal brakes tokeep the vehicle stationary.
A
B
This 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. 351)
• Brake functions (p. 348)
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. 346)
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350
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. 348)
• Airbag system (p. 89)
• Rear Collision Warning (RCW) (p. 292)
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. 346)
• Hazard warning flashers (p. 147)
• Brake lights (p. 146)
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 withthe accelerator pedal. When the acceleratorpedal is released, the vehicle will return to verylow speed. The driver can use the brakes to slow or stop the vehicle at any time. HDC is activated along with Low Speed Control (LSC), which together make driving on slipperysurfaces at low speeds easier.