Hdc Hill Descent Control - Volvo V70 Owner's Manual

1
General
HDC can be compared to an automatic
engine brake. When you release the accelera-
tor on downhill gradients the car is normally
braked by means of the engine striving for
low engine idling speeds, so-called engine
braking. But the steeper the road and the
more load there is in the car, the faster the
car rolls despite engine braking. In order to
then reduce speed the driver has to assist
using the foot brake.
WARNING
HDC does not work in all situations, but is
instead only intended to be supplementary
assistance.
The driver always has ultimate responsibil-
ity that the car is driven safely.
HDC makes it possible to increase/reduce
speed on steep downhill gradients, with a
foot only on the accelerator pedal, without
using the foot brake. The sensitivity of the
accelerator pedal decreases and becomes
more precise by means of the full actuation of
the pedal being restricted to adjusting engine
speed within a limited range. The brake sys-
tem brakes itself and provides the car with a
HDC is only available on the XC70.
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low and even speed, so allowing the driver to
fully focus on steering.
HDC is particularly helpful on steep gradients
with an uneven road surface and slippery
sections. E.g. when launching a boat on a
trailer from a ramp.
Function
HDC is engaged or disengaged using a
switch on the centre console. An indicator
lamp in the button illuminates when the func-
tion is switched on.
When HDC is operating this symbol
illuminates and the combined instru-
Hill descent control ON
ment panel shows
03 Your driving environment

HDC Hill Descent Control

The function only operates with gear 1 or
reverse gear R - with automatic gearbox the
combined instrument panel then shows the
1 R
character or , see page 128.
NOTE
HDC cannot be activated in an automatic
gearbox with the gear selector in position
D.
Operation
HDC allows the car to roll at a maximum of
10 km/h forwards with engine braking and
7 km/h backwards. However, any speed
within the gear's speed register can be
selected using the accelerator pedal. When
the accelerator pedal is released, the car is
braked quickly to 10 or 7 km/h respectively,
irrespective of the hill's gradient and without
the need for the foot brake.
The brake lights come on automatically when
the function is operating. The driver can brake
or stop the car at any time by using the foot
brake.
HDC is deactivated:
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