Manual First Gear. Cadillac Concours 1996

For 1990-2009 cars

For a view of the oil flow diagram, refer to the 1996 TURM Manual.

When the gear selector lever is moved to the Manual First (1) gear range, the manual valve moves and allows line pressure to enter the Lo fluid passage. If the vehicle is operating below 56 km/h (35 mph), the transmission will shift immediately into first gear. the transmission is prevented from upshifting. During the shift into Manual First gear, the following changes occur within the transmission:

### LO & REVERSE BAND APPLIES

#### Manual Valve

Line pressure at the manual valve enters the Lo fluid circuit. Line pressure is then routed to checkball #8.

### #8 Checkball (Lo)

Lo fluid pressure unseats the #8 checkball, which is located in the valve body. This pressure then routes Lo fluid to the 2-3 shift valve.

### 2-3 Shift Valve

Spring force hold the 2-3 shift valve in the downshifted position. Lo fluid passes through the valve and Lo fluid enters the Lo feed circuit. Lo feed passes through orifice #4, and Lo feed enters the orificed Lo feed circuit. Lo feed is then routed to the 1-2 shift valve.

### 1-2 Shift Solenoid Valve

When the PCM energizes (turns ON) the 1-2 shift solenoid valve, high fluid pressure from the 1-2 shift solenoid valve builds at the end of the 1-2 shift valve. This causes the valve to downshift against spring force.

### 1-2 Shift Valve

Fluid pressure from the 1-2 shift solenoid valve holds the 1-2 shift valve in the downshifted position. The valve allows orificed Lo feed to pass through the valve and enter the Lo & Reverse band reduce circuit. Lo & Reverse band reduce is then routed to checkball #6 and to the spring side of the Lo & Reverse servo piston.

### #6 Checkball (Lo Reverse Band Apply and Reduce)

The #6 checkball is located in the valve body. The checkball is unseated by Lo & Reverse reduce fluid. This allows fluid to enter the Lo & Reverse band apply circuit. Lo & Reverse band apply fluid is then routed to the Lo & Reverse servo piston where the fluid actuates the piston and applies the Lo & Reverse band assembly.

### FOURTH BAND RELEASES

#### 1-2 Shift Valve

High fluid pressure from the 1-2 shift solenoid valve holds the 1-2 shift valve in the downshifted position. The valve allows fourth band fluid from the fourth servo and from the 3-4 accumulator piston to pass through the valve. Fourth band fluid then enters an exhaust passage where the fluid is routed through orifice #2 before exiting the circuit.

### SECOND CLUTCH RELEASES

#### 1-2 Shift Valve

High solenoid a fluid pressure holds the 1-2 shift valve in the downshifted position. The valve allows second clutch fluid from the second clutch piston and from the 1-2 accumulator piston to pass through the valve and to exhaust.