BMW M5 Owner's Handbook Manual page 323

Tyre inflation pressure decreases if the tyre tem‐
perature drops.
Through this behaviour, a warning may be trig‐
gered if there are major temperature drops, due
to the given warning limits.
After a temperature-related warning, the speci‐
fied pressures are displayed again on the Control
Display after a short journey.
Sudden loss of tyre inflation
pressure
No warning can be given by the system of ex‐
treme, sudden tyre failure caused by external
factors.
Reset not carried out
Tyres with special approval: the system will not
function correctly if a reset has not been carried
out, for example, a flat tyre is reported in spite of
the correct tyre pressure.
Malfunction
Message
The yellow warning lamp flashes and is
then illuminated continuously. A Check
Control message is shown. Tyre pres‐
sure losses cannot be detected.
Measure
▷ A wheel without TPM wheel electronics is fit‐
ted: have the wheels checked if necessary.
▷ Malfunction: have the system checked.
▷ Fault due to systems or devices with the
same radio frequency: the system is auto‐
matically reactivated upon leaving the field of
interference.
▷ In the case of tyres with special approval: the
system was unable to complete the reset.
Perform a system reset again.
Online Edition for Part no. 01402989787 - II/18
Wheels and tyres
Runflat indicator RPA
Principle
The system identifies a loss of tyre inflation pres‐
sure by comparing the rotational speeds of the
individual wheels during the journey.
If a tyre loses inflation pressure, its diameter
changes. This in turn alters the rotational speed
of the corresponding wheel. The difference will
be detected and reported as a flat tyre.
The system does not measure the tyre inflation
pressure as such.
Operating requirements
The following requirements must be met for the
system, otherwise reliable signalling of a loss of
tyre inflation pressure is not ensured:
▷ After every tyre or wheel change, an initialisa‐
tion must be carried out with the correct tyre
inflation pressure.
▷ An initialisation must be carried out after the
tyre inflation pressure has been adjusted to a
new value.
Status display
It is possible to display the current status of the
runflat indicator, for example to check whether
the RPA is active.
Via iDrive:
1. "My Vehicle"
2. "Vehicle status"
3. "Flat Tyre Monitor"
The status is displayed.
Initialisation required
An initialisation must be performed in the
following situations:
▷ After adjusting the tyre inflation pressure.
▷ After a tyre or wheel change.
MOBILITY
323