2015 VOLVO XC90 brakes

STARTING AND DRIVING
* Option/accessory, for more information, see Introduction.
332
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 message is shown in the information display: DO NOT DRIVE . Have the vehicle towed to a
trained and qualified Volvo service technician and have the brake system inspected.
Related information
• Brake functions (p. 332)
• Brake assist system (p. 333)
• Emergency brake lights (p. 334)
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. 330)
• Parking brake (p. 335)
• Hill Descent Control (HDC) (p. 334)
• Auto-hold brake function (p. 332)
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.

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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
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. 335)
• Brake functions (p. 332)
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.
NOTE
•When BAS is activated, the brake pedal will go down farther than usual. Depressthe pedal as long as necessary.
• Braking will stop when the pedal isreleased.
Related information
•Brakes (p. 330)
Braking effect after a collision
In the event of a collision in which the airbags or seat belt pretensioners deploy or if a collisionwith an animal is detected, the vehicle's brakesare 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. 332)
• Airbag system (p. 83)
• Rear Collision Warning (RCW) (p. 277)

STARTING AND DRIVING
* Option/accessory, for more information, see Introduction.
334
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. 330)
• Hazard warning flashers (p. 144)
• Brake lights (p. 143)
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. When HDC and LSC are activated, this changes the response from the accelerator pedal andengine.
Activating HDCHDC only functions at low speeds.
Using the driving mode control
*
Select the Off Road driving mode to activate
HDC. 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.
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 function is deactivated when driving at higher speeds and must be reactivated atlower speeds if so desired.

STARTING AND DRIVING
* Option/accessory, for more information, see Introduction.335
Related information
•Brake functions (p. 332)
• Low Speed Control (LSC) (p. 371)
• Drive modes
* (p. 359)
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. 332)
• Auto-hold brake function (p. 332)
Parking brake The electric parking brake helps to keep the vehicle stationary when it is parked.

STARTING AND DRIVING
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Parking brake control in the tunnel console between the front seats
NOTE
•A faint sound from the parking brake's electric motor can be heard when theparking brake is being applied. Thissound can also be heard during the auto-matic function check of the parkingbrake.
• The brake pedal will move slightly whenthe electric parking brake is applied orreleased.
If the vehicle is not moving when the parking brake is applied, only the rear wheels are affec-ted. If it is applied while the vehicle is moving, thenormal brakes are used on all four wheels. Thebrakes will only be applied on the rear wheelsonce the vehicle has stopped.
Related information
• Brake functions (p. 332)
• Using the parking brake (p. 336)
• Parking brake malfunctions (p. 338)
Using the parking brake
The electric parking brake helps to keep the vehicle stationary when it is parked.
Applying the parking brake
1. Put the gear selector in P.
2. Press firmly on the brake pedal.
3. Pull up the control. > The symbol in the instrument panelflashes while the parking brake is being applied and glows steadily when the park-ing brake has been fully applied.
4. Release the brake pedal and ensure that the vehicle is stationary.

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Before a long distance trip
It is always worthwhile to have your vehicle checked by a trained and qualified Volvo servicetechnician before driving long distances. Yourretailer will also be able to supply you with bulbs,fuses, spark plugs and wiper blades for your usein the event that problems occur.
As a minimum, the following items should be checked before any long trip:
• Check that engine runs smoothly and that fuel consumption and the oil level are normal.
• Check for fuel, oil, and fluid leakage.
• Have the transmission oil level checked.
• Check condition of drive belts.
• Check state of the battery's charge.
• Examine tires carefully (including the sparetire where applicable), and replace those thatare worn. Also, check tire inflation pressure.
• The brakes, front wheel alignment, and steer-ing gear should be checked by a trained andqualified Volvo service technician only.
• Check all lights, including high beams.
• Reflective warning triangles are legallyrequired in some states/provinces.
• Have a word with a trained and qualifiedVolvo service technician if you intend to drivein countries where it may be difficult toobtain the correct fuel. •
Consider your destination. If you will be driv-ing through an area where snow or ice arelikely to occur, consider using snow tires.
Driving economically
Better driving economy can be obtained by thinking ahead, avoiding rapid starts and stopsand adjusting the speed of your vehicle to imme-diate traffic conditions.
Economical driving conserves natural
resources
Observe the following rules: • Bring the engine to normal operating tem- perature as soon as possible by driving witha light foot on the accelerator pedal for thefirst few minutes of operation. A cold engineuses more fuel and is subject to increasedwear.
• Whenever possible, avoid using the vehiclefor driving short distances. This does notallow the engine to reach normal operatingtemperature.
• Drive carefully and avoid rapid accelerationand hard braking.
• Use the transmission's Drive (
D) position as
often as possible and avoid using kick-down.
• Using the engine's Eco function can helpimprove fuel economy.
• Do not exceed posted speed limits.
• Avoid carrying unnecessary items (extra load)in the vehicle.
• Maintain correct tire pressure. Check tirepressure regularly (when the tires are cold).

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Remove snow tires when threat of snow or ice has ended.
• Note that roof racks, ski racks, etc, increaseair resistance and also fuel consumption.
• At highway driving speeds, fuel consumptionwill be lower with the air conditioning on andthe windows closed than with the air condi-tioning off and the windows open.
• Using the onboard trip computer's fuel con-sumption modes can help you learn how todrive more economically.
Other factors that decrease gas mileage are:
• Dirty air cleaner
• Dirty engine oil and clogged oil filter
• Dragging brakes
• Incorrect front end alignment
Some of the above mentioned items and others are checked at the standard maintenance inter-vals.
Handling and roadholding
• Vehicle load, tire design and inflation pres- sure all affect vehicle handling. Therefore,check that the tires are inflated to the rec-ommended pressure according to the vehicleload. Loads should be distributed so thatcapacity weight or maximum permissible axleloads are not exceeded.
• At the specified curb weight your vehicle hasa tendency to understeer, which means thatthe steering wheel has to be turned more than might seem appropriate for the curva-ture of a bend. This ensures good stabilityand reduces the risk of rear wheel skid.Remember that these properties can alterwith the vehicle load. The heavier the load inthe cargo compartment, the less the ten-dency to understeer.
Driving through standing water
The vehicle should be driven with extreme cau- tion if it is necessary to drive through standingwater.
The vehicle can be driven through water up to a depth of approximately 17.7 in. (45 cm) at walk-ing speed to help prevent water from enteringthe differential and the transmission. Thisreduces the oil's lubricating capacity and mayshorten the service life of these components.
• Take particular care when driving through flowing water.
• After driving through water, apply the brakesand check that they are functioning correctly.
• Clean the electrical connections for trailerwiring after driving in mud or water.
• When driving through water, maintain lowspeed and do not stop in the water.

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CAUTION
•Engine damage will occur if water is drawn into the air cleaner.
• Damage to any components, the engine,transmission, turbo-charger, differential orits internal components caused by flood-ing, vapor lock or insufficient oil is notcovered under warranty.
• Do not allow the vehicle to stand in waterup to the door sills longer than absolutelynecessary. This could result in electricalmalfunctions.
• If the engine has been stopped while thevehicle is in water, do not attempt torestart it. Have the vehicle towed out ofthe water.
WARNING
•Avoid driving through standing or rushing water. Doing so can be dangerous and itmay also be difficult to determine theactual depth of the water.
• If water cannot be avoided, after drivingthrough the water, press lightly on thebrake pedal to ensure that the brakes arefunctioning normally. Water or mud canmake the brake linings slippery, resultingin delayed braking effect.
Related information
•Towing recommendations (p. 344)
Overheating the engine and transmission
In demanding driving conditions, such as when transporting heavy loads, driving in mountainousareas or in very hot weather there is a risk ofoverheating the engine or transmission.
• The engine's output may be slightly limited if there is a risk of overheating.
• Remove e.g., auxiliary lights mounted in frontof the grille in hot weather.
• If the temperature of the engine coolantbecomes too high, the warning symbol will illuminate and the message
Engine
temperature/Stop safely will be displayed.
Stop the vehicle as soon as possible in a safe place and let the engine idle for severalminutes.
• If the message
Engine temperature/High
temperature Turn off engine or Engine
coolant/Stop safely is displayed, stop
safely and turn off the engine.
• If the transmission begins to overheat, an alternative gear shifting program will beselected. An integrated protective functionwill also by activated, the warning symbol will illuminate and the message
Transmission
warmHigh temperature Reduce speed
or Transmission warmStop safely, wait
for cooling will be displayed in the instru-
ment panel.