Volvo 2013 XC70 - Manual (Page 129)

03 Your driving environment
Hill Descent Control (HDC)*
03
* Option/accessory, for more information, see Introduction. 127
Introduction
Normally, when the accelerator pedal is
released while driving down hills, the vehicle's
speed slows as the engine runs at lower rpm
(the normal engine braking effect). However, if
the downhill gradient becomes steeper and if
the vehicle is carrying a load, speed increases
despite the engine braking effect. In this situa-
tion, the brakes must be applied to reduce the
vehicle's speed.
HDC is a type of automatic engine brake and
makes it possible to increase or decrease the
vehicle's speed on downhill gradients using
only the accelerator pedal, without applying
the brakes. The brake system functions auto-
matically to maintain a low and steady speed.
HDC is particularly useful when driving down
steep hills with rough surfaces, and where the
road may have slippery patches.
WARNING
HDC does not function in all situations, and
is a supplementary braking aid. The driver
has full responsibility for driving in a safe
manner.
Function
• HDC can be switched on and off with the
button in the center console. An indicator
light in the button illuminates when HDC is
activated.
•
The indicator light in the instrument
panel illuminates and a message is dis-
played when the system is controlling the
vehicle's speed.
• HDC only functions when first or reverse
gears are selected (
1 will be shown in the
instrument panel display when first gear is
selected).
NOTE
HDC cannot be activated if the gear selector
is the D position.
Using HDC
HDC allows the car to roll forward at a maxi-
mum speed of 6 mph (10 km/h), and 4 mph
(7 km/h) in reverse. However, the accelerator
pedal can be used to select any speed that is
possible in first or reverse gears. When the
accelerator pedal is released, speed is quickly
reduced again to 6 mph (10 km/h) or 4 mph
(7 km/h), depending on the gear selected,
regardless of the hill's gradient. It is not nec-
essary to apply the brakes.
• The brake lights illuminate automatically
when HDC is controlling the vehicle's
speed.
• The driver can slow or stop the vehicle at
any time by applying the brakes.
HDC is deactivated when:
• The button on the center console is
pressed
• A gear higher than first gear is selected
• D is selected on vehicles with an automatic
transmission
HDC can be deactivated at any time. If this is
done while driving down a steep hill, the sys-
tem's braking effect will decrease gradually.