Porsche Boxster Owner's Manual page 155

This tire pressure warning appears
– for approx. 10 seconds with vehicle stopped
when switching off the ignition or
– again when switching on the ignition.
With ignition on, the warning can be deactivated.
The tire pressure warning light in the instrument
panel goes out only when the tire pressure has
been corrected.
Stage 2 – Flat tire
At speeds below 100 mph (160 km/h):
The pressure in the tire has dropped by more
than 7 psi (0.5 bar). This significant pressure
loss is a danger to road safety.
At speeds above 100 mph (160 km/h):
The pressure in the tire has dropped by more
than 5 psi (0.4 bar). This significant pressure
loss is a danger to road safety.
f When the tire pressure warning appears, stop
immediately at a suitable location. Check the
indicated tire for signs of damage. If neces-
sary, fill in tire sealant and set the correct tire
pressure.
This tire pressure warning also appears when
driving and can be acknowledged.
The tire pressure warning light on the instrument
panel goes out only when the tire pressure has
been corrected.
Instruments, On-Board Computer, Warnings
153