Subaru 2003 Impreza - Manual (Page 87)

IMPREZA(NA) A1850BE-A (ENGLISH)
Seat, seatbelt and SRS airbags
1-62
There are many types of collisions which might not
necessarily require SRS side airbag deployment. In
the event of accidents like those illustrated, the SRS
side airbag may not deploy depending on the level
of accident forces involved. n When will the SRS side airbag not deploy?
1) The vehicle is involved in a frontal collision with
another vehicle (moving or stationary).
2) The vehicle is struck from behind.