Inspection Procedure A-6: Power liftgate automatic operation does not work normally by the operation of power liftgate close switch (only the close of automatic operation): Notes
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.
CAUTION:
Before replacing the ECU, ensure that the input and output signal circuits are normal.