Active steering, Technology for comfort, convenience and safety – BMW X5 xDrive35d 2009 User Manual
Page 106
Technology for comfort, convenience and safety
104
>
If a wheel without TPM electronics is
mounted, e.g. a compact wheel
*
>
If TPM is temporarily interfered with by
other systems or devices which use the
same radio frequency
Explanation according to the NHTSA/
FMVSS 138 Tire Pressure Monitoring
Systems
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recommended
by the vehicle manufacturer on the vehicle plac-
ard or tire inflation pressure label. (If your vehi-
cle has tires of a different size than the size indi-
cated on the vehicle placard or tire inflation
pressure label, you should determine the
proper tire inflation pressure for those tires.)
As an added safety feature, your vehicle has
been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low tire pres-
sure telltale when one or more of your tires is
significantly underinflated. Accordingly, when
the low tire pressure telltale illuminates, you
should stop and check your tires as soon as
possible, and inflate them to the proper pres-
sure. Driving on a significantly underinflated tire
causes the tire to overheat and can lead to tire
failure. Underinflation also reduces fuel effi-
ciency and tire tread life, and may affect the
vehicle's handling and stopping ability.
Please note that the TPMS is not a substitute
for proper tire maintenance, and it is the driver's
responsibility to maintain correct tire pressure,
even if underinflation has not reached the level
to trigger illumination of the TPMS low tire
pressure telltale.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate when
the system is not operating properly. The
TPMS malfunction indicator is combined with
the low tire pressure telltale. When the system
detects a malfunction, the telltale will flash for
approximately one minute and then remain con-
tinuously illuminated. This sequence will con-
tinue upon subsequent vehicle start-ups as
long as the malfunction exists. When the mal-
function indicator is illuminated, the system
may not be able to detect or signal low tire pres-
sure as intended. TPMS malfunctions may
occur for a variety of reasons, including the
installation of replacement or alternate tires or
wheels on the vehicle that prevent the TPMS
from functioning properly. Always check the
TPMS malfunction telltale after replacing one or
more tires or wheels on your vehicle to ensure
that the replacement or alternate tires and
wheels allow the TPMS to continue to function
properly.
Active steering*
The concept
The active steering actively varies the steering
angle of the front wheels in relation to the steer-
ing wheel movements. In addition, it also varies
the steering force required for steering depend-
ing on the vehicle's speed.
When you are driving in the low road speed
range, e.g. in a town or when parking, the steer-
ing angle increases, i.e. the steering becomes
very direct. In the higher speed range, on the
other hand, the steering angle is reduced more
and more. This improves the handling capability
of your BMW over the entire speed range.
In critical situations, the system can make tar-
geted corrections to the steering angle pro-
vided by the driver and thus stabilize the vehicle
before the driver intervenes.
Malfunction
The warning lamp lights up yellow
and a message is shown on the Con-
trol Display. The active steering is
defective or has been temporarily
deactivated. At low speeds, greater steering
wheel movements are required, whereas at
higher speeds, the vehicle reacts more sensi-
tively to steering wheel movements. The stabil-
ity-promoting intervention can also be deacti-
vated. Proceed cautiously and drive
defensively. If active steering is defective, have
the system checked.
Online Edition for Part no. 01 41 2 600 792 - © 09/08 BMW AG