4C Clutch
WARNING: This page is about a different car, the 2005 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
The 4C clutch is hydraulically applied in second prime and fourth gear by pressurized fluid against the 4C clutch piston. When the 4C clutch is applied, the reaction annulus gear is held or grounded to the transmission case.