BMW X1 Owner's Manual page 334

MOBILITY
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.
The system does not measure the actual infla-
tion pressure in the tires.
The system detects tire pressure loss on the
basis of rotation speed differences between
the individual wheels while driving.
If a tire loses pressure, the diameter and
thus the rotational speed of the corresponding
wheel changes. The difference will be detected
and reported as a flat tire.
Functional requirements
If the following requirements are not met for
the Flat Tire Monitor, a loss in tire pressure
may not be reliably reported:
▷ 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 on the control display, e.g., to
check whether the Flat Tire Monitor is active.
Go through the menu as follows via iDrive:
Apps menu / "Vehicle" / "Vehicle status" / "Flat
Tire Monitor".
The status is displayed.
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Wheels and tires
Online Edition for Part no. 01405A8A536 - VI/23
Initialization required
The Flat Tire Monitor must be initialized in the
following situations:
▷ After the tire inflation pressure has been
adjusted.
▷ After a tire or wheel change.
Performing initialization
When initializing the Flat Tire Monitor, the tire
pressures you set serve as a reference value
for detecting a flat tire. Initialization is started
by confirming the tire inflation pressures.
Do not initialize the system when driving with
snow chains.
To initialize the Flat Tire Monitor, proceed as
follows:
1. Go through the menu as follows via iDrive:
Apps menu / "Vehicle" / "Vehicle status" /
"Flat Tire Monitor".
2. Turn on drive-ready state but do not drive
off.
3. To begin initialization, select "Perform
reset".
4. Drive off.
The initialization is completed while driving,
which can be interrupted at any time.
The initialization automatically continues when
driving continues.
Messages
General information
The Tire Pressure Monitor displays a message
when a tire is flat.
When a flat tire is indicated, the Dynamic Sta-
bility Control (DSC) is turned on, if needed.