Porsche 911 Turbo Owner's Manual page 155

The warning light in the speedometer lights up:
– When a loss in pressure has been detected.
– When learning newly mounted wheels/wheel
sensors, as long as the vehicle's own wheels
have not yet been recognized.
In the event of a defect in Tire Pressure Monitoring
or a temporary fault, the warning light in the
speedometer flashes for approx. one minute and
then remains continuously illuminated.
The tire pressure warning light in the instrument
panel goes out only when the cause of the fault
has been rectified.
Partial monitoring
Monitoring of the other wheels is continued if there
is a fault in one or two wheel transmitters.
– The tire pressure warning light lights up.
– The message "TPM partial monitoring" is
displayed on the on-board computer.
– No tire pressures are displayed on the on-
board computer for wheels with faulty wheel
transmitters.
No monitoring
In the event of faults the Tire Pressure Monitoring
cannot monitor the tire pressure.
The warning light in the speedometer flashes for
approx. one minute and then remains continuously
illuminated and a corresponding message
appears on the on-board computer.
Monitoring is not active when:
– the Tire Pressure Monitoring is faulty,
– wheel transmitters for the Tire Pressure
Monitoring are missing,
– during the learning phase after the tire settings
have been updated,
– after a wheel change without updating the tire
settings,
– more than four wheel transmitters are
detected,
– there is external interference by other radio
sources, e.g. wireless headphones,
– tire temperatures are too high.
f Please see the chapter "WARNINGS ON THE
INSTRUMENT PANEL AND THE ON-BOARD
COMPUTER" on Page 160.
Pressure increase as the result of
temperature increase
In accordance with physical principles, the air
pressure changes as the temperature changes.
The tire pressure increases or decreases by
around 1.5 psi (0.1 bar) for every 18 °F (10 °C)
change in temperature.
The Tire Pressure Monitoring takes this relation-
ship between tire pressure and temperature into
account.
Tire pressure specifications
Information on tire pressure for public roads can
be found in this Owner's Manual in the Technical
Data chapter or on the tire-pressure plate in the
left door aperture.
These values apply to cold tires at 68 °F (20 °C)
ambient temperature.
Instruments, On-Board Computer, Warnings
153