Inspection Procedure 13: The rain sensitive AUTO wiper function does not work at all < Vehicles with LDW camera (rain sensor) >: Operation
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.
The raindrops sensitive wiper function automatically adjusts the wiping speed of windscreen wiper by detecting the rainfall through LDW-ECU (rain sensor) when the ignition switch is in the ON position and the column switch is in the AUTO position.