Manual Valve

WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

Line pressure is routed into the Low fluid circuit when the selector lever is moved into the Manual First (1) position. Line pressure continues to feed the Drive, the D321, and the D21 fluid circuits as in Manual Second.

A/T Fluid Pressure Manual Valve Position Switch (TFP Val. Position Sw.) Assembly

Low fluid pressure is routed to the TFP Val. Position Sw. Assembly, which signals to the PCM that the manual valve is in the Manual First position.

#1 Checkball (Low/PRN)

Low fluid pressure seats the #1 checkball against the PRN fluid circuit and this pressure fills the Low/PRN fluid circuit. Low/PRN fluid is routed to the 1-2 shift valve.

1-2 Shift Solenoid Valve

The PCM energizes the 1-2 shift solenoid valve when vehicle speed is below approximately 48-56 km/h (30-35 mph). The 1-2 signal fluid is blocked from exhausting through the solenoid valve.

1-2 Shift Valve

The 1-2 signal fluid pressure shifts the valve into the downshifted position against a spring force, and the following changes occur:

The 2-3 drive fluid circuit is open to an exhaust past the valve
The intermediate band fluid is exhausted past the valve
the Lo/PRN fluid is routed into the low band fluid circuit