
Brake support prepares the brake system to react quickly, and the brakes are applied slightly. This may be experienced
as a light tug.
If the brakes are applied quickly, full braking effect will be provided, even if pressure on the brake pedal is light.
Auto-brake
If a collision is imminent and the driver has not applied the brakes, the auto-brake function is activated without the
driver pressing the brake pedal. Limited brake force is applied to reduce the vehicle's speed when the collision occurs.
WARNING
The driver must apply the brakes for full braking effect.
NOTE
The auto-brake function is always on and cannot be turned off.
Operation
Settings are made from the center console via a menu system. See page 122
for information on using the menu system.
On and off
To switch Collision Warning on or off, go into the menu Car settings
Collision warning settings and select On or
Off . When the engine is started, the setting that was selected when it was switched off will be used.
Activating/deactivating warning signals
The collision warning system's audible and visual signals are activated automatically when the engine is started if the
collision warning system is activated.
The audible warning signal can be activated/deactivated by selecting the alternative On or Off in Car settings
Collision warning settings Warning sound.
Setting a warning distance
This setting determines the distance at which the visual and audible warnings are triggered. Select Long , Normal, or
Short under Car settings
Collision warning settings Warning distance .
The warning distance determines the level of sensitivity used by the system. The warning distance Long provides an
earlier warning. Begin by using Long and if the system gives too many warnings, try changing to Normal .
WARNING
The setting Short should only be used in situations where traffic is light and moving at low speeds.
Collision Warning alerts the driver to the risk of a collision but this function cannot reduce the driver's reaction
time.
For Collision Warning to be as effective as possible, it is recommended that Distance Alert be set to 4 or 5, see
page 163
.
NOTE
When Adaptive Cruise Control (ACC) is used, the warning light and signal will be used by ACC, even if Collision
Warning has been switched off.
In situations where traffic is moving at considerably different speeds, or if the vehicle ahead brakes suddenly,
warnings may be considered to be late, even if the setting Long has been selected.

Checking settings
The current Collision Warning settings can be checked by going into the menu system at
168 04 Comfort and driving pleasure
Collision Warning with Auto-brake (option)
Car settings Collision warning settings. See page 122 for more information on the menu system.
Limitations
Strong sunlight, reflections, extreme light contrasts, the use of sunglasses, or if the driver is not looking straight ahead
may make the visual warning signal in the windshield difficult to see. For this reason, always activate the audible
warning signal in such conditions.
NOTE
The visual warning signal may be temporarily disengaged in the event of high passenger compartment temperature
due to strong sunlight, etc. If this occurs, the audible warning signal will be used, even if it has been deactivated in
the menu system.
Warnings may not appear if the distance to the vehicle ahead is very small or if steering wheel and pedal movements
are great, for example, due to a very active driving style.
WARNING
In certain situations, the system cannot provide warnings or warning may be delayed if traffic conditions or other
external factors make it impossible for the radar sensor or camera to detect the vehicle ahead.
Warnings may not be provided if the distance to the vehicle ahead is short, or if movements of the steering
wheel/brake pedal are great, such as during active driving.
The sensor system has a limited range for stationary or slow-moving vehicles and may therefore give delayed or
no warnings if your vehicle's speed is above approximately 45 mph (70 km/h).
Warnings for stationary or slow-moving vehicles may not be provided in dark conditions.
The Collision Warning system uses the same radar sensors as Adaptive Cruise Control. For more information on the
radar sensor and its limitations, see page 160
.
If no warning is given, or if a warning is delayed, Auto-brake will also not be provided or will be delayed.
NOTE
If warnings are given too frequently, the warning distance can be reduced (see "Setting a warning distance" on page
167). This causes the system to provide later warnings, which decreases the total number of warnings provided.
The camera's limitations
The camera is used by Collision Warning with Auto-brake, Driver Alert Control (see page 171
), and Lane Departure
Warning (see page 174
).
NOTE
Keep the section of the windshield in front of the camera clean and free of ice, snow, or condensation.

169 04 Comfort and driving pleasure
Collision Warning with Auto-brake (option)
WARNING
The camera has the same limitations as the human eye. In other words, its "vision is impaired" by adverse weather
conditions such as heavy snowfall, dense fog, etc. These conditions may reduce the function of systems that depend
on the camera or cause these systems to temporarily stop functioning.
Never place any objects, decals, etc., on the windshield in front of the camera. This could reduce or block the
camera's function, and could cause one or more of the systems that utilize the camera to stop functioning.
Strong sunlight, reflections from the road surface, a dirty road surface, or unclear lane marker lines may
drastically reduce the camera's capacity to detect the side of a lane or another vehicle.
Fault tracing and actions
If the message Camera blocked See manual is displayed, this means that the camera is obscured and cannot detect
vehicle or road marker lines in front of the vehicle.
This, in turn, means that Collision Warning with Auto-brake, Lane Departure Warning, and Driver Alert Control will
not have full functionality.
The table lists possible causes for this message being displayed, and suitable actions.
170 04 Comfort and driving pleasure
Collision Warning with Auto-brake (option)
Symbols and messages in the display

171 04 Comfort and driving pleasure
Driver Alert System -option
Introduction
The Driver Alert System is designed to help a driver who may be becoming fatigued or who is inadvertently leaving
the lane.
The Driver Alert System consists of two different functions that can be switched on together or separately.
Driver Alert Control (DAC)
Lane Departure Warning (LDW)
When one or both of the functions has been switched on, it is in standby mode and is activated when the vehicle
exceeds a speed of 40 mph (65 km/h).
The function deactivates if speed goes under 37 mph (60 km/h).
Both functions use a camera that is dependent on the road/lane being clearly marked by painted lines on each side.
WARNING
The Driver Alert System does not function in all situations and is designed to be a supplementary aid. It is not,
however, intended to replace the driver's attention and judgement.
Driver Alert Control (DAC)-general information

This function is intended to alert the driver if his/her driving becomes erratic, such as if the driver is distracted or
fatigued.
A camera monitors the painted lines marking the lane in which the vehicle is traveling and compares the direction of
the road with the driver's movements of the steering wheel. The driver is alerted if the vehicle does not follow the lane
smoothly.
NOTE
The camera has certain limitations, see page 168
.
DAC is designed to help detect a slowly changing driving pattern. It is primarily intended to be used on main roads
and is not meant for use in city traffic.
WARNING
DAC is not intended to extend the duration of driving. Always plan breaks at regular intervals to help remain
alert.
In certain cases, fatigue may not affect the driver's behavior. In situations of this type, no warning will be
provided. Therefore, it is important to take breaks at regular intervals, regardless of whether or not DAC has given a
warning
Limitations
In certain situations, DAC may provide warnings even if the driver's driving pattern has not become erratic.
if the driver is testing the LDW function
in strong crosswinds
on grooved road surfaces.
172 04 Comfort and driving pleasure
Driver Alert System -option
Operating DAC
Certain settings can be made from the menu system controlled from the center instrument panel. See page 122
for
more information on the menu system.
The current system status can be checked on the trip computer's display by using the buttons on the left steering wheel
lever.
![VOLVO S80 2008 Owners Manual Thumb wheel. Turn this wheel until Driver Alert is displayed. The second line shows the alternative Off,
Unavailable , or [-----], i.e., the number of bars.
READ button. Confirms and erases a me VOLVO S80 2008 Owners Manual Thumb wheel. Turn this wheel until Driver Alert is displayed. The second line shows the alternative Off,
Unavailable , or [-----], i.e., the number of bars.
READ button. Confirms and erases a me](/manual-img/45/59287/w960_59287-168.png)
Thumb wheel. Turn this wheel until Driver Alert is displayed. The second line shows the alternative Off,
Unavailable , or [-----], i.e., the number of bars.
READ button. Confirms and erases a message in the display.
Activating DAC
In the center instrument panel, go to Car settings
Driver Alert . Select On.
The function is activated when the vehicle exceeds a speed of 40 mph (65 km/h). The display will
show level markings of 1-5 bars, where a low number of bars indicates erratic driving. A high number
of bars indicates stable driving.
If the vehicle is being driven erratically, the driver will be alerted by an audible signal and the message Driver Alert,
Time for a break is displayed. The warning will be repeated after a short time if the driving pattern remains the same.
WARNING
An alert should be taken seriously since it is sometimes difficult for a driver to realize that he/she is fatigued.
In the event of a warning or if the driver feels fatigued, stop as soon as possible in a safe place and rest.
173 04 Comfort and driving pleasure
Driver Alert System -option
Symbols and messages in the display

174 04 Comfort and driving pleasure
Driver Alert System -option
Lane Departure Warning (LDW)-general information
This function is designed to help reduce the risk of accidents in situations where the vehicle leaves its lane and there is
a risk of driving off the road or into the opposite lane.
LDW consists of a camera that monitors the lane's side marker lines. The driver is alerted by an audible signal if the
vehicle crosses a side marker line or the road's center dividing line.
Operation and function
LDW can be switched on or off by pressing the button on the center console. A light in the button illuminates when the
function is on.
The trip computer display shows Lane Depart Warn Unavailable when the function is in standby mode.
When LDW is in standby mode, the function is activated automatically after the camera has monitored the road's side
marker lines and the vehicle's speed exceeds 40 mph (65 km/h). Lane Depart Warn Available will be displayed.
If the camera can no longer monitor the road's side marker lines, or if the vehicle's speed falls below 37 mph (60
km/h), LDW will return to standby mode and Lane Depart Warn Unavailable will be displayed.
If the vehicle unexpectedly crosses the lane's left or right side marker lines, the driver will be alerted by an audible
signal.
No warning signal will be given in the following situations:
The turn signal is being used
The driver's foot is on the brake pedal1

The throttle pedal is pressed quickly
If the steering wheel is moved quickly
In sharp turns that cause the vehicle's body to sway.
The camera also has certain limitations. See page 168
for information.
WARNING
The driver will only be warned once for each time the wheels cross a marker line. No alarm will be given if a marker
line is between the wheels.
1A warning will be given even when Increased sensitivity has been selected. See page 123 for more information
175 04 Comfort and driving pleasure
Driver Alert System -option
Symbols and messages in the display
Settings
Settings for Lane Departure Warning can be made in the menu system under Car settings
Lane Departure Warning.
See page 122
for more information on the menu system.
On at startup : This selection puts the function in standby mode each time the engine is started. Otherwise, the system
will be in the mode that it was in when the engine was switched off.
Increased sensitivity : This selection increases the function's sensitivity. Warnings will be given at an earlier stage and
fewer limitations apply.
176 04 Comfort and driving pleasure
Driver Alert System -option
Introduction
The park assist system is designed to assist you when driving into parking spaces, garages, etc.