Safety
Controls
vehicle has tires of a different size than the size
indicated on the vehicle placard or tire inflation
pressure label, you should determine the
proper tire inflation pressure for those tires.)
As an added safety feature, your vehicle has
been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low tire pres‐
sure telltale when one or more of your tires is
significantly under-inflated. Accordingly, when
the low tire pressure telltale illuminates, you
should stop and check your tires as soon as
possible, and inflate them to the proper pres‐
sure. Driving on a significantly under-inflated
tire causes the tire to overheat and can lead to
tire failure. Under-inflation also reduces fuel ef‐
ficiency and tire tread life, and may affect the
vehicle's handling and stopping 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. Your vehicle has also
been equipped with a TPMS malfunction indi‐
cator to indicate when the system is not oper‐
ating properly. The TPMS malfunction indica‐
tor is combined with the low tire pressure
telltale. When the system detects a malfunc‐
tion, the telltale will flash for approximately one
minute and then remain continuously illumi‐
nated. This sequence will continue upon sub‐
sequent vehicle start-ups as long as the mal‐
function exists. When the malfunction indicator
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 replace‐
ment or alternate tires or wheels on the vehicle
that prevent the TPMS from functioning prop‐
erly. Always check the TPMS malfunction tell‐
tale after replacing one or more tires or wheels
on your vehicle to ensure that the replacement
or alternate tires and wheels allow the TPMS
to continue to function properly.
FTM Flat Tire Monitor
Concept
The system detects tire inflation pressure loss
on the basis of rotation speed differences be‐
tween the individual wheels while driving.
In the event of a tire inflation pressure loss, the
diameter and therefore the rotational speed of
the corresponding wheel changes. The differ‐
ence will be detected and reported as a flat
tire.
The system does not measure the actual infla‐
tion pressure in the tires.
Functional requirements
The following conditions must be met for the
system; otherwise, reliable flagging of a loss of
tire inflation pressure is not assured:
▷
After a tire or wheel replacement, an initial‐
ization was performed with the correct tire
inflation pressure.
▷
After the tire inflation pressure was ad‐
justed to a new value, an initialization was
performed.
Status display
The current status of the flat tire monitor can
be displayed, for instance whether the RPA is
active.
Using iDrive:
1. "Vehicle info"
2. "Vehicle status"
3.
"Flat Tire Monitor (FTM)"
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 replacement.
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