BMW 328i xDrive Owner's Manual page 101

Controls
Drive-off assistant
The drive-off assistant enables you to drive off
smoothly on uphill gradients. It is not necessary
to use the parking brake for this.
1. Hold the car in place by depressing the
brake.
2. Release the brake and drive off without
delay.
The drive-off assistant holds the car in
place for approx. 2 seconds after the
brake is released. Drive off without delay after
releasing the brake. Otherwise, the drive-off
assistant will no longer hold the car in place
after approx. 2 seconds and the car will start to
roll backwards.<
Flat Tire Monitor FTM
The concept
The system does not measure the actual infla-
tion pressure in the tires.
The system detects a pressure loss in a tire by
comparing the rotational speeds of the individ-
ual wheels while moving.
In the event of a pressure loss, the diameter and
therefore the rotational speed of the corre-
sponding wheel change. This is detected and
reported as a flat tire.
Functional requirement
The system must have been initialized while the
tire inflation pressure was correct; otherwise,
reliable signaling of a flat tire is not ensured.
Each time a tire inflation pressure has been cor-
rected or a wheel or tire has been changed,
reinitialize the system.
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Technology for driving comfort and safety
Online Edition for Part no. 01 40 2 609 333 - © 08/11 BMW AG
System limitations
Sudden serious tire damage caused by
external influences cannot be indicated in
advance.<
A natural, steady pressure loss in all four tires is
not detected. Therefore, check the tire inflation
pressure regularly.
In the following situations, the system could be
delayed or malfunction:
> System has not been initialized
> Driving on snowy or slippery road surface
> Performance-oriented style of driving: slip
in the drive wheels, high lateral acceleration
> Snow chains are attached
Status display
The current status of the Flat Tire Monitor can
be displayed on the Control Display, e.g.
whether or not the FTM is active.
1. "Vehicle Info"
2. "Vehicle status"
3. "Flat Tire Monitor"
The status is displayed.
Initialization
The initialization process adopts the set infla-
tion tire pressures as reference values for the
detection of a flat tire. Initialization is started by
confirming the inflation pressures.
Do not initialize the system when driving with
snow chains.