Hill descent control, Hill descent control hdc – BMW AG User Manual

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Hill Descent Control HDC*

The principle

HDC is a system that reduces speed on
steep downhill gradients, making your
BMW even easier to control under
these conditions.

Without any intervention on your part,
the car's speed is kept down to about
twice walking pace.

You can activate HDC at speeds less
than approximately 35 km/h (22 mph).
On a descent, the car automatically
reduces speed from under approx.
35 km/h (22 mph) to about twice walk-
ing pace – approx. 12 km/h (7.5 mph) –
and then maintains this constant speed.

You can press the brake pedal or open
the throttle to vary the car's speed in a
range from approximately 5 km/h
(3 mph) to 25 km/h (15.5 mph).

You also have the option of setting a
speed in this range using the +/– but-
tons of the cruise control system.

HDC is automatically deactivated when
the car accelerates to a speed of
approximately 60 km/h (37 mph).

Activating the system

Press the HDC button: the green telltale
light in the button comes on.

The telltale light flashes when the car is
automatically braked.

Deactivating the system

Press the button a second time; the
telltale light goes out.

HDC is deactivated automatically when
the car's speed increases to approx.
60 km/h (37 mph) or when the ignition
is switched off.

Using HDC

Cars with manual shift:

Use HDC in first gear and in reverse,
because the engine's braking effect
diminishes in higher gears.

Cars with automatic transmission: you
can use HDC with the selector lever in
any drive position.

In the event of a fault

The telltale light in the button goes out
while HDC is active or fails to come on
when HDC is activated:

HDC is temporarily unavailable on
account of high brake temperatures.

The DSC telltale light comes on
as well:

Failure in the HDC and DSC

system. Have the system checked.

Overview

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