Circuit description
WARNING: This page is about a different car, the 2018 Subaru BRZ. However, it is still accessible from the selected car via links, so may be relevant.
When the clutch pedal is released, ECM receives positive (+) battery voltage through IG2 fuse. While the clutch pedal is depressed, the clutch switch sends signals to ECM terminal CLT. When terminal CLT receives the signal, ECM cancels the cruise control driving.