Porsche 911 TURBO - 1975 WORSHOP, Manual

Page: 100 / 252

100
Controls, Safety, Instruments
No monitoring
In the event of faults, Tyre Pressure Monitoring
cannot monitor the tyre pressure.
The warning light on the instrument panel lights up
and a corresponding message appears on the on-
board computer.
Monitoring is not active when:
– Tyre Pressure Monitoring is faulty,
– wheel transmitters for Tyre Pressure
Monitoring are missing,
– temporarily after changing a wheel (learning
phase),
– more than four wheel transmitters are recog-
nised,
– there is external interference by other radio
sources, e.g. wireless headphones,
– tyre temperatures are too high.
f
Please observe the chapter “WARNINGS ON
THE INSTRUMENT PANEL AND THE ON-
BOARD COMPUTER” on page 106.
A
- Tyre pressure
B - Tyre temperature
C - Tyre pressure for cold tyres
D - Tyre pressure for warm tyres
E
- Pressure increase as the result of temperature
increase
F - Pressure drop in faulty/leaky tyres
Pressure increase as the result of
temperature increase
1. Required-pressure line
2. Warning stage 1 (from –0.2 bar to –0.4 bar
(–3 to –6 psi))
3. Warning stage 2 (from –0.4 bar (–6 psi))
In accordance with physical principles, the air
pressure changes as the temperature changes.
The tyre pressure increases or decreases by
around 0.1 bar (1.5 psi) for every 10 °C (18 °F)
change in temperature.
Tyre Pressure Monitoring takes this relationship
between tyre pressure and temperature into
account.
Tyre pressure specifications
Information on tyre pressure for public roads can
also be found in this Driver's Manual or on the tyre-
pressure plate in the left door aperture.
These values apply to cold tyres at 20 °C (68 °F).
f
Only use the pressure specifications from the
“Info pressure” display in the Tyre pressure
menu or from the respective tyre pressure
warning to correct the tyre pressure.