BMW Z4 sDrive35i 2009 - Manual (Page 83)

Co
n
tr
o
ls
81
Refere
nce
At a glan
ce
Dr
ivi
n
g ti
ps
Commu
nication
s
Navigation
Ente
rt
ai
nme
n
t
M
o
bi
lity
Flat Tire Monitor FTM*
The concept
The Flat Tire Monitor detects pressure loss in a
tire by comparing the rotating speeds of the
individual tires while moving.
In the event of pressure loss, the rolling circum-
ference changes and, thus, the rotating speed
of the affected wheel. This change is detected
and is reported as a flat tire.
Functional requirement
In order to assure the reliable reporting of a flat
tire, the system must be initialized for the cor-
rect tire inflation pressure.
The system must be reinitialized each
time a tire inflation pressure has been cor-
rected or a wheel or tire has been changed. <
System limitations
The Flat Tire Monitor is unable to warn
the driver of sudden, severe tire damage
caused by external factors, nor can it identify
the gradual loss of pressure that will inevitably
occur in all four tires over a lengthy period
of time.
<
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
Initializing the system
The initialization is completed during driv-
ing, which can be interrupted at any time.
When driving resumes, the initialization is con-
tinued automatically.
Do not initialize the system while snow chains
are attached.
<
iDrive, for operating principle refer to page 16 .
1. "Vehicle Info"
2. "Vehicle status"
3. "Reset"
4. Start the engine - do not drive away.
5. Start the initialization using "Reset".
6. Start to drive.
The initialization is completed during the trip.
The initialization is completed during driving,
which can be interrupted at any time.
When driving resumes, the initialization is con-
tinued automatically.
Indication of a flat tire
The warning lamps come on in yellow
and red. A message appears on the
Control Display. In addition, an
acoustic signal sounds. There is a flat
tire or substantial loss of tire pressure.
1. Cautiously reduce speed to below 50 mph
or 80 km/h. Avoid sudden braking and
steering maneuvers. Do not exceed a speed
of 50 mph or 80 km/h.
If the car is not equipped with Run-
Flat Tires, refer to page
195 , the stan-
dard equipment by design, do not continue
driving. Otherwise a severe accident could
result if you continue driving.
<
2. At the next opportunity, check the air pres-
sure in all four tires.
If all four tires are inflated to the cor-
rect pressures, the Flat Tire Monitor
might not have been initialized. The system
must then be initialized.
<
Online Edition for Part no. 01 41 2 602 116 - © 01/09 BMW AG