>> A << Seatback Frame Assembly Installation
WARNING: This page is about a different car, the 2014 Mitsubishi Outlander. However, it is still accessible from the selected car via links, so may be relevant.
To route the side airbag module wiring harness under the seat cushion, guide it through the fastener on the rear end of the seat cushion cover.
When the side airbag module is fitted in the seatback frame assembly, wrap reinforcement fabric of the seatback cover around the side airbag module and hook the assembly to the seatback frame assembly as shown in the figure, and then tighten the tapping screw securely.