BMW serie 7 1999 Manual Do Utilizador

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Repairs
Index
Overview
Controls
Car care
Technology
Data
In order to take driving conditions into 
account, ATC registers corners and 
both uphill and downhill gradients. For 
example, if you maintain speed through 
a curve, the transmission does not up-
shift. 
On uphill gradients, it shifts only when 
the engine speed increases in order to 
make more efficient use of power re-
serves. On downhill gradients ATC 
downshifts when the speed of the vehi-
cles increases causing the driver to 
step on the brakes.
With respect to road conditions, ATC 
monitors the friction between the tires 
and the road. The system responds to 
slippery road surfaces (snow and ice) 
by activating the winter program. 
Second gear is used when moving 
away from a standstill, upshifts occur 
sooner, and on descents downshifting 
does not occur in spite of the applica-
tion of brakes. This enables you to 
"feel" the road as you drive and pro-
duces greater dynamic stability. If the 
friction between the tires and the road 
is adequate, the normal system is again 
activated. The system also leaves the 
winter program when you shift from 
drive position "D" to "S," "3" or "2," or if 
the ASC+T/DSC
*
 is deactivated.
By recognizing traffic conditions, ATC 
can retain maximum driving comfort. 
For instance, the system recognizes 
stop-and-go traffic and then proceeds 
only in second gear until it encounters 
higher starting loads.
Of course the selector lever can still be 
used to select specific gear ratios. Per-
formance-oriented driving is enabled by 
shifting from drive position "D" to "S," 
"3" or "2." Positions "3" and "2" each 
limit upshifts to the next gear. Position 
"2" is best for driving on steep mountain 
slopes with a heavy load.
Precision sensors monitor the number 
of revolutions of the wheels. When 
equipped with DSC, they also monitor 
steering angle, lateral acceleration, 
brake pressure and the movement of 
the vehicle around its vertical axis. 
If differences in the wheel speeds oc-
cur, the system counteracts the danger 
of wheelspin by reducing torque. If nec-
essary, the system also responds with 
additional applications of the brakes at 
the rear wheels.
If the system detects an instability in the 
vehicle's condition, the braking action 
can also be directed to the front wheels 
by the DSC in order to stabilize the ve-
hicle. 
You may need some time to become 
accustomed to this system intervention. 
However, it helps provide optimum pro-
pulsive force and driving stability.
The braking intervention may be ac-
companied by a certain degree of 
noise.
ATC
ASC+T/DSC
*
Online Edition for Part-No. 01 41 9 791 187 - © 12/98 BMW AG