Vauxhall Corsa Owner's Manual page 29

If the diesel particle filter needs cleaning
and recent driving situations did not allow
the function to automatically operate, then
control indicator ! will flash. If this occurs,
then you may continue to drive the vehicle
normally. The vehicle will not be damaged
and does not require service.
The self-cleaning function will
automatically operate while driving after
the engine has reached its normal
operating temperature. Control
indicator ! will continue to flash until the
self-cleaning operation is complete. This
may take up to 20 minutes of driving. The
time will be shorter at higher vehicle
speeds.
6 Diesel particle filter – see page 164.
In brief 25