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2006 VOLVO XC90
Driving in rain and slush or passing through an automatic car wash can c\
ause water to collect on the
brake discs and pads. This will cause a delay in braking effect when the\
pedal is depressed. To avoid
such a delay when the brakes are needed, depress the pedal occasionally \
when driving through rain,
slush, etc. This will remove the water from the brakes. Check that brake\
application feels normal. This
should also be done after washing or starting in very damp or cold weath\
er.
Severe strain on the brake system
The brakes will be subject to severe strain when driving in mountains or\
hilly areas, or when towing a
trailer. Vehicle speed is usually slower, which means that the cooling o\
f the brakes is less efficient than
when driving on level roads. To reduce the strain on the brakes, shift i\
nto a lower gear and let the engine
help with the braking. Do not forget that if you are towing a trailer, t\
he brakes will be subjected to a
greater than normal load.
pg. 97 Starting and driving
Brake system (contd)
Anti-lock brakes (ABS)
If the warning lamp lights up there is a malfunction of the ABS system (\
the standard braking system will
however function) and the vehicle should be driven cautiously to a Volv\
o retailer for inspection. The
Anti-lock Braking System (ABS) helps to improve vehicle control (stop\
ping and steering) during severe
braking conditions by limiting brake lockup. When the system "senses" im\
pending lockup, braking
pressure is automatically modulated in order to help prevent lockup, whi\
ch could lead to a skid.
This system performs a self-diagnostic test when the engine is started a\
nd when the vehicle first
reaches a speed of approximately 12 mph (20 km/h). The brake pedal will pulsate several times and a
sound may be audible from the ABS control module. This is normal.
To obtain optimal effect from the ABS system, constant pressure should b\
e kept on the brake pedal. Do
not pump the brake pedal.
The switching of the ABS modulator will be audible and the brake pedal w\
ill pulsate during braking.
Please be aware that ABS does not increase the absolute braking potentia\
l of the vehicle. While control
will be enhanced, ABS will not shorten stopping distances on slippery su\
rfaces.
ABS with EBD (Electronic Brake Force Distribution)
EBD is an integrated part of the ABS system. EBD regulates the hydraulic\
pressure to the rear brakes to
help provide optimal braking capacity. The brake pedal will pulsate duri\
ng braking, which is normal.
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2006 VOLVO XC90
the difference in speed is immediately detected. This triggers the Anti-\
lock Brake System, which brakes
the spinning wheel until the difference in rotational speed is corrected\
.
TC is most active at low speeds, and a pulsating sound will be audible w\
hen the system is regulating
wheel spin. This is quite normal.
This is one of the DSTC system's permanent functions and is not affected\
when the DSTC button on the
center control panel is pressed.
2. Spin control (SC)
The spin control function is designed to help prevent the drive wheels f\
rom spinning while the vehicle is
accelerating. This is done by temporarily reducing engine torque to the \
drive wheels, which helps
improve tractive force.
Under certain circumstances, such as when driving with snow chains, or d\
riving in deep snow or loose
sand, it may be advisable to temporarily switch off this function for ma\
ximum tractive force. This is
done by pressing the DSTC button on the center control panel for at leas\
t a half a second.
When the SC function has been switched off:
l The text window will briefly display "DSTC SPIN CONTROL OFF"
l The LED in the DSTC button will be off.
3. Active Yaw Control (AYC)
This function helps maintain directional stability, for example when cor\
nering, by braking one or more
of the wheels if the vehicle shows a tendency to skid or slide laterally\
. This is done by activating the
Anti-lock Braking System. A pulsating sound will be audible when the fun\
ction is active, which is quite
normal. If you apply the brakes while this function is active, the brake\
pedal will feel stiffer than usual.
This is also one of the DSTC system's permanent functions and is not aff\
ected when the DSTC button on
the center control panel is pressed.
4. Roll Stability Control (RSC)
RSC utilizes a gyro-sensor to monitor the vehicle's angle of inclination\
, and the rate at which this angle
changes. If necessary, RSC activates the Anti-lock Brake System to brake\
one or more of the wheels to
help maintain stability. A pulsating sound will be audible when the func\
tion is active, which is quite
normal. If you apply the brakes while this function is active, the brake\
pedal will feel stiffer than usual.
This is one of the DSTC system's permanent functions and is not affected\
when the DSTC button on the
center control panel is pressed.
The DSTC button
The DSTC button in the center control panel is used to switch the Spin C\
ontrol (SC) function on or off.
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The button must be pressed for at least a half second to prevent SC from\
being switched off
inadvertently.
When the system has been switched off, the green indicator lamp in the b\
utton will go out and "DSTC
SPIN CONTROL OFF" will be displayed in the text window.
All DSTC functions are (re)activated each time the engine is started.
pg. 99 Starting and driving
Dynamic Stability Traction Control (DSTC) (contd)
The Stability Control indicator light
The Stability Control indicator light will come on for approximately 2 s\
econds when the ignition is
switched on as the system performs a self-diagnostic test.
The Stability Control indicator light will flash when:
l Traction Control is actively functioning to help avoid drive-wheel spin.\
l Spin Control is actively functioning to help avoid loss of traction duri\
ng acceleration.
l Active Yaw Control is actively functioning to help avoid skids or latera\
l slides.
l Roll Stability Control is actively functioning to help avoid a roll-over\
situation.
The warning symbol in the instrument panel
A steady yellow glow indicates:
l That the system has been automatically disengaged due to a fault. "ANTI \
SKID SERVICE
REQUIRED" will be displayed in the text window. If this occurs, stop the\
vehicle in a suitable place,
switch off and restart the engine. If the light remains on, an authorize\
d Volvo retailer should check the
system.
l In the event of high brake temperature, "TRACTION CONTROL TEMPORARILY OF\
F" will be
displayed in the text window.
The system will automatically switch on again when the brakes have coole\
d.
pg. 100 Starting and driving
Park assist
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