Shift Control Mechanism
WARNING: This page is about a different car, the 2011 Acura TL, 2010 Acura TL, and 2009 Acura TL. However, it is still accessible from the selected car via links, so may be relevant.
To shift gears, the PCM controls shift solenoid valves A, B, C and D, and automatic transmission (A/T) clutch pressure control solenoid valves A, B, and C The shift solenoid valves change the positions of the shift valves in the valve body which open and close ports to send hydraulic pressure to the appropriate clutch A/T clutch pressure control solenoid valves A, B, and C change the position of CPC valves A and B, and the reverse CPC valve, to control hydraulic pressure going to the clutches, which allows smooth shifts between gears