BMW XM Owner's Manual page 356

MOBILITY
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 under-inflation has not
reached the level to trigger illumination of the
TPMS low tire pressure telltale. The vehicle
has also been equipped with a TPMS malfunc-
tion indicator to indicate when the system is
not operating properly. The TPMS malfunction
indicator is combined with the low tire pres-
sure telltale. When the system detects a mal-
function, the telltale will flash for approximately
one minute and then remain continuously il-
luminated. This sequence will continue upon
subsequent vehicle start-ups as long as the
malfunction exists. When the malfunction indi-
cator is illuminated, the system may not be
able to detect or signal low tire pressure 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 function-
ing properly. Always check the TPMS malfunc-
tion telltale after replacing one or more tires
or wheels on the vehicle to ensure that the re-
placement or alternate tires and wheels allow
the TPMS to continue to function properly.
Flat tire monitor
Principle
The flat tire monitor detects a tire pressure
loss while driving and issues a warning if the
tire pressure has dropped.
General information
The system detects tire pressure loss on the
basis of rotation speed differences between
the individual wheels while driving.
In the event of a tire pressure loss, the diame-
ter and therefore the rotational speed of the
corresponding wheel changes. The difference
will be detected and reported as a flat tire.
356
Wheels and tires
Online Edition for Part no. 01405A8A608 - VI/23
The system does not measure the actual infla-
tion pressure in the tires.
Functional requirements
The following prerequisites must be met for
the system; otherwise, reliable notification of a
tire pressure loss is not assured:
▷ After a tire or wheel change, an initialization
was carried out at the correct tire pressure.
▷ After the tire pressure was adjusted to a
new value, an initialization was performed.
Status display
The current status of the flat tire monitor can
be displayed, e.g., whether the flat tire monitor
is active.
1. Apps menu
2. "Vehicle"
3. "Vehicle status"
4. "FLAT TIRE MONITOR"
The status is displayed.
Initialization required
An initialization must be performed in the fol-
lowing situations:
▷ After the tire inflation pressure has been
adjusted.
▷ After a tire or wheel change.
Performing initialization
When initializing, the set tire inflation pressures
serve as reference values in order to detect a
flat tire. Initialization is started by confirming
the tire inflation pressures.
Do not initialize the system when driving with
snow chains.
1. Apps menu
2. "Vehicle"
3. "Vehicle status"
4. "FLAT TIRE MONITOR"