Low and Reverse Band Applies

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.

Manual Valve

The gear selector lever mechanically controls the manual valve, which is in Park (P) position. The manual valve directs line pressure into the PRND4 and the PRN fluid circuits.

Automatic Transmission Fluid Pressure Manual Valve Position Switch (TFP Val. Position Sw.) Assembly

PRND4 fluid is routed to the PRND4 fluid pressure switch in the TFP Val. Position Sw. Assembly, which signals the PCM that the transmission is in the Park (P) position. Line pressure is routed to the A/T Fluid Temperature Sensor in the TFP Val. Position Sw. Assembly.

1-2 Shift Solenoid Valve

Energized by the PCM, the normally open 1-2 shift solenoid valve is On and blocks the 1-2 signal fluid from exhausting. The 1-2 signal fluid pressure acts on the 1-2 and the 3-4 shift valves.

1-2 Shift Valve

The 1-2 signal fluid pressure holds the valve in the downshifted position against a spring force. Low/PRN fluid is routed through the 1-2 shift valve and into the Low band fluid circuit.

Low and Reverse Servo

Low band fluid is routed to the inner area of the servo piston. Low band fluid pressure moves the servo piston and pin assembly against a spring force in order to apply the low/reverse band. The low band fluid is routed to the 3-4 shift valve. The pressure moves the valve against 1-2 signal fluid.

2-3 Shift Solenoid Valve

The normally open 2-3 shift solenoid is Off and the 2-3 signal fluid is exhausted through the solenoid.

2-3 Shift Valve

A spring force holds the 2-3 shift valve in the downshifted position.

3-4 Shift Valve

The 1-2 signal fluid pressure holds the 3-4 shift valve against a spring force in the First and the Fourth gear positions.

Lube 2

The lube 2 fluid circuit is fed by line pressure at the pressure regulator valve. Lube 2 fluid is routed through the oil feed pipes and into the forward clutch support. Lube 2 fluid provides lubrication in the rear of the transmission.