Test Y: Seat Track Position Sensor Open (DTC C1946): Description
WARNING: This page is about a different car, the 2004 Mercury Monterey and 2004 Ford Freestar. However, it is still accessible from the selected car via links, so may be relevant.
Restraints Control Module (RCM) monitors seat track position switch circuits for faults. If RCM detects an open circuit, it will store Diagnostic Trouble Code (DTC) C1946 in memory and flash Code 4-9 on AIR BAG warning light.