WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Seat Slide Sensor Circuit Diagram
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
CAUTION:
If DTC B1B8D is set in the occupant classification-ECU, always diagnose the CAN main bus lines.