Hdc hill descent control – BMW X5 4.8is SAV 2004 User Manual

Page 98

HDC Hill Descent Control

The concept

HDC is a system for driving downhill in
steep terrain. This system reduces vehi-
cle speed on steep downhill gradients,
thus allowing you to maintain control of
your BMW under these conditions.
The vehicle moves at slightly more than
walking speed without active interven-
tion from the driver.

HDC is available for activation at vehi-
cle speeds below approx. 20 mph/
35 km/h. When driving down steep hills
with a speed below approx. 20 mph/
35 km/h, the vehicle reduces speed
automatically down to slightly more
than walking speed, approx. 5 mph/
8 km/h, and then maintains this speed
at a constant.

You can use the accelerator or brakes
to vary this automatically controlled
speed within a range extending from
approx. 3 mph/5 km/h to 15 mph/
25 km/h.
You can specify a target speed within
the same range by using the +/– but-
tons of the cruise control.

HDC is automatically deactivated once
vehicle speed again exceeds approx.
35 mph/60 km/h.

Activating system

Press the button, the indicator lamp
lights up.

The indicator lamp flashes when the
brakes are applied automatically.

Deactivating system

Press the button again; the indicator
lamp goes out.

HDC is deactivated automatically
above a road speed of approx. 35 mph/
60 km/h and when the ignition is
switched off.

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Using HDC

With manual transmission:
Use HDC in first gear and in Reverse
since the engine's braking effect is
diminished in the higher gears.

With automatic transmission:
You can use HDC in every drive posi-
tion.

In case of a malfunction

The indicator lamp in the button goes
out in the HDC mode or does not come
on when HDC is switched on:
HDC is temporarily not available as
brake temperature is too high.