3rd Clutch Oil Pressure Switch
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The 3rd clutch pressure switch is located in the hydraulic passage to the 3rd clutch. When oil pressure is supplied to the 3rd clutch, the switch is grounded. When oil pressure is not supplied, the switch is open. The PCM receives the signal from the 3rd clutch pressure switch to detect the fluid pressure status, in order to reduce the shift shock upon shifting to 3rd gear, 2nd to 3rd, or 4th to 3rd.