2017 VOLVO XC90 TWIN ENGINE HYBRID brake sensor

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DRIVER SUPPORT
* Option/accessory, for more information, see Introduction.286

WARNING
When ACC is in standby mode, the driver hasto control the vehicle's speed and distance toa vehicle ahead.
When ACC is in standby mode, the driver willbe alerted if the distance to the vehicle aheadis too short by the Distance Alert function.See the article "Distance Alert" for additionalinformation.

Standby mode due to action by the driver
ACC is temporarily deactivated and put instandby mode if:
•the brakes are applied
•The gear selector is moved to N
•the vehicle is driven faster than the setspeed for more than 1 minute.
In these cases, the driver will have to regulate thevehicle's speed.
A temporary increase in speed, such as whenpassing another vehicle, does not affect the ACCset speed. The vehicle will return to the set speedwhen the accelerator pedal is released.

Automatic standby mode
ACC interacts with other systems, such asElectronic Stability Control. If any of these othersystems are not functioning properly, ACC willturn off automatically.
WARNING
If this happens, the driver will be alerted by anaudible signal and a message in the instru-ment panel. The driver will have to adapt thevehicle's speed, apply the brakes when nec-essary and keep a safe distance to the vehicleahead.
ACC switches automatically to standby mode if:
•the vehicle's speed goes below approx.3 mph (5 km/h) and ACC cannot determineif the vehicle ahead is stationary or is anobject such as a speed bump, etc
•the vehicle's speed goes below approx.3 mph (5 km/h) and the vehicle aheadchanges lanes or turns so that ACC nolonger has a target vehicle to follow
•the driver opens the door
•the driver unbuckles the seat belt
•the engine speed (rpm) is too high/low
•the wheels lose traction
•the brake temperature is too high
•the parking brake is applied
•the stability system's ESC Sport Mode isactivated
•the Off Road drive mode is selected
•The radar sensor is covered by e.g., wet snowor if heavy rain interferes with radar waves
Reactivating ACC from standby mode
Generic illustration
To reactivate ACC after it has temporarily beenput in standby mode:
–Press the button (1).
>The vehicle will then return to the mostrecently set speed.

WARNING
There may be a significant increase in speed
after the button has been pressed.

Related information
•Adaptive Cruise Control (ACC)* (p. 281)
•Starting and activating Adaptive CruiseControl (ACC)* (p. 284)
•Setting an Adaptive Cruise Control timeinterval (p. 288)

DRIVER SUPPORT
* Option/accessory, for more information, see Introduction.292
Adaptive Cruise Control (ACC) -limitations
Adaptive Cruise Control (ACC) functionality maybe limited in certain situations.

Steep roads and/or heavy loads
Adaptive Cruise Control is primarily intended foruse on relatively level roads. The function may notbe able to maintain the correct time interval tothe vehicle ahead when driving down steep hills.The driver should be attentive and prepared toapply the brakes in these situations.
Do not use Adaptive Cruise Control when thevehicle is transporting a heavy load or if it is tow-ing a trailer.

Additional information
•The Off Road drive mode cannot beselected if Adaptive Cruise Control is acti-vated.
•Adaptive Cruise Control uses the vehicle'scamera and radar sensor, which have certaingeneral limitations. See the articles "Cameralimitations" and "Radar sensor limitations"for additional information.

Related information
•Adaptive Cruise Control (ACC)* (p. 281)
•Radar sensor limitations (p. 319)
•Camera limitations (p. 323)

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DRIVER SUPPORT
296
If the camera and radar sensor cannot detect thelane's side marker lines or a vehicle ahead, PilotAssist goes into standby mode.
When Pilot Assist is in standby mode and yourvehicle comes too close to the vehicle ahead, thedriver will be alerted by the Distance Alert func-tion.

WARNING
•Pilot Assist is designed to be a supple-mentary driving aid and cannot cover alldriving situations, traffic, weather and/orroad conditions.
•The driver should be familiar with all ofthe information in this article regardingPilot Assist, including its limitations.
•Pilot Assist is not intended to replace thedriver's attention and judgement.
•Pilot Assist must only be used wherethere are clearly visible traffic lane sidemarker lines on both sides of the currenttraffic lane. In other circumstances thereis an increased risk of collision with sur-rounding obstacles that are not detectedby the system.
•The driver is always responsible for steer-ing the vehicle and maintaining a suitablespeed and distance to the vehicle aheadand must intervene if necessary, even ifPilot Assist is being used.
Pilot Assist is designed to regulate speedsmoothly but in situations calling for fast braking,the driver must apply the brakes. This applies tosituations where there are considerable differen-ces in speed or if the vehicle ahead brakes sud-denly. Due to the limitations of the camera andradar sensor, the system may apply the brakes inyour vehicle suddenly or not at all.
•The default speed for Pilot Assist is preset toapprox. 30 mph (50 km/h) and cannot bechanged. If the vehicle ahead increasesspeed to over 30 mph (50 km/h) and pullsaway from your vehicle, Pilot Assist will gointo standby mode.

NOTE
•Pilot Assist maintenance should only becarried out by a trained and qualifiedVolvo service technician.
•Pilot Assist regulates your vehicle'sspeed using the accelerator pedal andthe brakes. Please be aware that theremay be a faint sound from the brakeswhen the system is using them.
WARNING
•Pilot Assist is not a collision avoidancesystem. The driver must react if the sys-tem does not detect another vehicle.
•Pilot Assist does not react to people, ani-mals, stationary objects, small vehicles(such as bicycles and motorcycles), lowtrailers and slow moving, parked orapproaching vehicles.
•Do not use Pilot Assist in demandingdriving conditions such as city driving orother heavy traffic situations, in slipperyconditions, when there is a great deal ofwater or slush on the road, during heavyrain or snow, in poor visibility, on windingroads or on highway on- or off-ramps.

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DRIVER SUPPORT
* Option/accessory, for more information, see Introduction.298

Head-up-display *
A flashing symbol alerts the driver
If the vehicle is equipped with a head-up display,a flashing symbol in the windshield will alert thedriver.

NOTE
Strong sunlight, reflections, extreme light con-trasts, the use of sunglasses, or if the driver isnot looking straight ahead may make the vis-ual warning signal in the windshield difficult tosee.
WARNING
Pilot Assist only provides warnings for vehi-cles that its radar sensor and camera havedetected. For this reason, a warning may begiven later than expected or not at all. Thedriver should never wait for a warning beforeapplying the brakes.

Related information
•Pilot Assist* (p. 295)
•Starting and activating Pilot Assist-1*(p. 298)
•Setting a Pilot Assist-1 time interval (p. 300)
•Deactivating/resuming Pilot Assist-1(p. 301)
•Automatic braking with Pilot Assist-1(p. 303)
•Pilot Assist-1 limitations (p. 304)
•Adaptive Cruise Control (ACC)* (p. 281)
•Distance Alert* (p. 279)
•Head-up display (HUD)* (p. 122)
•Radar sensor limitations (p. 319)
•Camera limitations (p. 323)
Starting and activating Pilot
Assist-1*
Pilot Assist has to be started and then activatedbefore it can provide steering assistance andregulate speed and the distance to the vehicleahead.
Function buttons and symbols

DRIVER SUPPORT
}}
299

Prerequisites
The prerequisites for activating Pilot Assist are:
•The vehicle ahead must be within a reasona-ble (detectable) distance
•The camera must be able to clearly detectthe traffic lane's side marker lines
•The vehicle's speed must be under approx.30 mph (50 km/h).
A WHITE symbol indicates thatPilot Assist has been selected.
In other cases, the WHITEarrow pointing to the right indi-cates that the system is availa-ble.
A YELLOW symbol with a flashing WHITE arrowindicates that the system is about to shift intostandby mode.
With ACC in standby mode:
1.Tap ▶ (6).
>The symbol will be displayed and PilotAssist will go into standby mode.
2.Press the button (2) on the left-sidesteering wheel keypad.
>Pilot Assist will go into active mode.

WARNING
Pilot Assist is not a collision avoidance sys-tem. The driver is always responsible forsteering or applying the brakes if the systemdoes not detect another vehicle.
Do not use Pilot Assist in demanding drivingconditions such as city driving or other heavytraffic situations, in slippery conditions, whenthere is a great deal of water or slush on theroad, during heavy rain or snow, in poor visibil-ity, on winding roads or on highway on- or off-ramps.
In certain situations, it may be difficult for PilotAssist to assist the driver correctly or to deac-tivate automatically. In such cases, it is advisa-ble not to use Pilot Assist. Examples of suchsituations may be:
•the lane's side market lines are missing,badly faded or cross each other.
•the division of lanes is not clear, e.g.,when a line divides or merges withanother, at exits or if there are many roadsigns/markers.
•there are edges or other lines on or nearthe lane, e.g., curbs, cracks, repairedareas, sharp shadows, etc.
•the lane is narrow or winding.
•the lane is at the top of a hill, on anuneven road surface or over a bump.
•bad weather conditions (rain, snow, fog,slush, poor visibility, backlighting, etc).
The driver should also be aware that PilotAssist has the following limitations:
•High curbs, barriers and temporary obsta-cles (cones, barriers etc) may not bedetected or could be detected incorrectlyas side marker lines, which may create arisk of collision. The driver must ensure asafe distance to these obstacles.
•The camera or radar sensor may not beable to detect objects if there are pot-holes or if there are stationary objectspartially or completely blocking the road.
•Pilot Assist does not "see" pedestrians,animals, etc.
•Pilot Assist's steering capacity is limitedand may not always be able to help thedriver keep the vehicle in the lane.

Hands on the steering wheel
Pilot Assist only functions when the driver'shands are on the steering wheel, which is con-tinuously monitored by the system. If this is notthe case, the driver will be alerted by a text mes-sage in the instrument panel. If the driver's handsare not returned to the steering wheel, an audiblesignal will sound.
If the driver does not return his/her hands to thesteering wheel after the audible signal, PilotAssist will go into standby mode and must be
reactivated by pressing .

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DRIVER SUPPORT
* Option/accessory, for more information, see Introduction.302

Automatic standby mode
Pilot Assist interacts with other systems, such asElectronic Stability Control. If any of these othersystems are not functioning properly, Pilot Assistwill automatically be deactivated.

WARNING
If this happens, the driver will be alerted by anaudible signal and a message in the instru-ment panel. The driver will have to adapt thevehicle's speed, apply the brakes when nec-essary and keep a safe distance to the vehicleahead.
Pilot Assist switches automatically to standbymode if:
•the camera cannot detect the traffic lane'sside marker lines
•the vehicle ahead is not within a reasonable(detectable) distance
•the driver's hands are not on the steeringwheel
•the driver unbuckles the seat belt
•engine speed (rpm) is too high/low
•the wheels lose traction
•brake temperature is too high
•the parking brake is set
•The camera lens/radar sensor is covered bye.g., wet snow or if heavy rain interferes withradar waves
Reactivating Pilot Assist from standby
mode
Function buttons and symbols
–Press the button (2).
>The most recently set speed will be usedand symbol (8) in the instrument panelwill change from WHITE to GRAY.

Related information
•Pilot Assist* (p. 295)
•Pilot Assist-1* (p. 295)
•Starting and activating Pilot Assist-1*(p. 298)
•Setting a Pilot Assist-1 time interval (p. 300)
•Automatic braking with Pilot Assist-1(p. 303)
•Pilot Assist-1 limitations (p. 304)
•Adaptive Cruise Control (ACC)* (p. 281)
•Distance Alert* (p. 279)

DRIVER SUPPORT
304
Pilot Assist-1 limitations
Pilot Assist functionality may be limited in certainsituations.
Pilot Assist is designed to help the driver in anumber of situations. However, the driver alwayshas the primary responsibility for maintaining asafe distance to other vehicles and for keepingthe vehicle in its proper traffic lane.

WARNING
Pilot Assist is not a collision avoidance sys-tem. The driver is always responsible forsteering or applying the brakes if the systemdoes not detect another vehicle.
Do not use Pilot Assist in demanding drivingconditions such as city driving or other heavytraffic situations, in slippery conditions, whenthere is a great deal of water or slush on theroad, during heavy rain or snow, in poor visibil-ity, on winding roads or on highway on- or off-ramps.
In certain situations, it may be difficult for PilotAssist to assist the driver correctly or to deac-tivate automatically. In such cases, it is advisa-ble not to use Pilot Assist. Examples of suchsituations may be:
•the lane's side market lines are missing,badly faded or cross each other.
•the division of lanes is not clear, e.g.,when a line divides or merges withanother, at exits or if there are many roadsigns/markers.
•there are edges or other lines on or nearthe lane, e.g., curbs, cracks, repairedareas, sharp shadows, etc.
•the lane is narrow or winding.
•the lane is at the top of a hill, on anuneven road surface or over a bump.
•bad weather conditions (rain, snow, fog,slush, poor visibility, backlighting, etc).
The driver should also be aware that PilotAssist has the following limitations:
•High curbs, barriers and temporary obsta-cles (cones, barriers etc) may not bedetected or could be detected incorrectlyas side marker lines, which may create arisk of collision. The driver must ensure asafe distance to these obstacles.
•The camera or radar sensor may not beable to detect objects if there are pot-holes or if there are stationary objectspartially or completely blocking the road.
•Pilot Assist does not "see" pedestrians,animals, etc.
•Pilot Assist's steering capacity is limitedand may not always be able to help thedriver keep the vehicle in the lane.
The driver can always take action to override PilotAssist.

Steep roads and/or heavy loads
Pilot Assist is primarily intended for use on rela-tively level roads. The function may not be able tomaintain the correct time interval to the vehicleahead on when driving down steep hills. Thedriver should be attentive and prepared to applythe brakes in these situations.
Do not use Pilot Assist when the vehicle is trans-porting a heavy load or if it is towing a trailer.

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DRIVER SUPPORT
306

WARNING
•Pilot Assist is designed to be a supple-mentary driving aid and cannot cover alldriving situations, traffic, weather and/orroad conditions.
•The driver should be familiar with all ofthe information in this article regardingPilot Assist, including its limitations.
•Pilot Assist is not intended to replace thedriver's attention and judgement.
•Pilot Assist must only be used wherethere are clearly visible traffic lane sidemarker lines on both sides of the currenttraffic lane. In other circumstances thereis an increased risk of collision with sur-rounding obstacles that are not detectedby the system.
•The driver is always responsible for steer-ing the vehicle and maintaining a suitablespeed and distance to the vehicle aheadand must intervene if necessary, even ifPilot Assist is being used.
Pilot Assist attempts to regulate speed smoothlybut in situations calling for fast braking, the drivermust apply the brakes. This applies to situationswhere there are considerable differences inspeed or if the vehicle ahead brakes suddenly.Due to the limitations of the camera and radarsensor, the system may apply the brakes in yourvehicle suddenly or not at all.
Pilot Assist is designed to follow a vehicle aheadin the same traffic lane at a preset time intervalset by the driver. If the radar sensor does notdetect a vehicle ahead, the vehicle will insteadmaintain the speed set by the driver. This will alsobe the case if a vehicle ahead accelerates andexceeds the set speed.
•Pilot Assist can follow another vehicle from astandstill up to a speed of approx. 125 mph(200 km/h)
•Pilot Assist can provide steering assistancefrom very low speeds up to approx. 87 mph(140 km/h).
Never exceed posted speed limits.

WARNING
•Pilot Assist is not a collision avoidancesystem. The driver must react if the sys-tem does not detect another vehicle.
•Pilot Assist does not react to people, ani-mals, stationary objects, small vehicles(such as bicycles and motorcycles), lowtrailers and slow moving, parked orapproaching vehicles.
•Do not use Pilot Assist in demandingdriving conditions such as city driving orother heavy traffic situations, in slipperyconditions, when there is a great deal ofwater or slush on the road, during heavyrain or snow, in poor visibility, on windingroads or on highway on- or off-ramps.
NOTE
•Pilot Assist maintenance should only becarried out by a trained and qualifiedVolvo service technician.
•Pilot Assist regulates your vehicle'sspeed using the accelerator pedal andthe brakes. Please be aware that theremay be a faint sound from the brakeswhen the system is using them.