Flat tire monitor – BMW 645Ci Coupe 2004 User Manual
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have dropped below the minimum, possi-
bly owing to a leak in the hydraulic system.
Do not continue driving. Contact your BMW
center.
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Flat Tire Monitor
The concept
The Flat Tire Monitor keeps track of the
inflation pressures in the four tires as you
drive. The system provides an alert when-
ever the inflation pressure drops signifi-
cantly in relation to the pressure in another
tire.
The check of the tire inflation pressure is
based on monitoring the relative speeds
of the wheels. A flat tire is detected and
reported on the basis of a deviation in cer-
tain speed ratios.
Functional requirement
To ensure reliable operation, the system
should have been initialized with the cor-
rect tire inflation pressure.
System limits
The Flat Tire Monitor cannot indicate
sudden severe tire damage caused
by outside factors and does not detect a
natural, even pressure drop in all four
tires.
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In the following situations, the system
could be delayed or malfunction:
>
When you are driving on snow-covered
or slippery road surfaces
>
In the case of performance-oriented
driving: slip on the drive wheels, high
lateral acceleration
>
False alarms and undetected loss of
pressure may occur when you are driv-
ing with snow chains fitted
>
If the Flat Tire Monitor was not initial-
ized after the last inflation pressure cor-
rection, false alarms indicating a flat tire
that is not present are possible or pres-
sure loss might not be detected.
Initializing system
Perform the initialization immediately
after correcting the inflation pressure,
after changing a tire or changing a wheel or
all wheels. A drive is necessary for this pur-
pose.
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Control Center, for principle details, refer to
page
1.
Start the engine, but do not drive off
2.
Open the menu
3.
Select "Vehicle settings" and press the
controller
4.
Select "FTM" and press the controller
5.
Select "Set tire pressure" and press the
controller
6.
Select "Yes" and press the controller
7.
Drive off.
The message "Initializing" is displayed.
It takes a few minutes before the Flat Tire
Monitor can detect and report a flat tire and
"Status: Active" is displayed.
If a flat tire is detected during initialization,
a message appears on the Control Display.
When driving with snow chains, do
not initialize the system.
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