Fifth bow up
WARNING: This page is about a different car, the 2001 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
The STC control module sends VR-bus message "Hydraulic valve 3 ON" and when hydraulic valve 3 is activated, pressure from the pump to pressure to the cylinders and the pistons are pressed, and the fifth bow is raised (opens).