Porsche 911 GT3 Owner's Manual page 61

Readiness for operation
PSM is switched on automatically every time you
start the engine.
PSM should always be switched on during
"normal" driving.
However, it may make sense to switch off PSM
temporarily in exceptional situations, for example:
– On a loose surface or in deep snow,
– when "rocking the vehicle free" and
– when using snow chains.
Switching off PSM
PSM can be switched off in 2 stages:
– Stage 1 SC OFF:
Switch off Stability Control (SC).
– Stage 2 SC+TC OFF:
Also switch off Traction Control (TC).
60
Operation, Safety
Danger!
There is a risk of accident due to loss of
control of the vehicle. There is no stabilizing
brake control in either switch-off stages
(even when the brakes are used).
f PSM should always be switched on during
"normal" driving. This particularly applies in
wet conditions.
Switching off Stability Control (SC)
Precondition:
The light-emitting diode in the SC+TC OFF button
must be off.
f Press SC OFF button.
Stability Control is switched off after a short
delay.
The light-emitting diode in the button is lit up.
When the system is switched off, the multi-
functional PSM light on the instrument panel
is lit and the message "SC OFF" appears
continuously on the on-board computer.
An acoustic signal also sounds.
– When Stability Control is switched off, sportier
Traction Control is activated.
– Brake control is deactivated.
– The ABS remains active.
Switching Stability Control (SC) back on
f Press SC OFF button.
Stability Control is switched on after a short
delay.
The light-emitting diode in the button and the
multi-functional PSM light on the instrument
panel go out.
The on-board computer shows a message.