When the selector lever is moved from Neutral (N) to Drive (D), the transmission shifts from neutral to first range operation. Shift solenoid 1 (SS1), SS2, and SS3 remain energized. Pressure control solenoid 1 (PCS1) and the torque converter clutch (TCC) solenoid remain de-energized.

Shift valve 1, shift valve 2, and shift valve 3 stay in the stroked position. With normally closed PCS1 de-energized, pressure control valve 1 continues to supply full control pressure through shift valve 2 to the low and reverse clutch, keeping the clutch applied. During the shift, PCS2 energizes, blocking the exhaust of the PCS2 signal pressure, causing the pressure to rise. The PCS2 signal pressure strokes pressure control valve 2, opening the pressure control valve 2 pressure port to main pressure. PCS2 pressure is directed through shift valve 1, shift valve 3, and the manual selector valve to the 1-2-3-4 clutch, applying the 1-2-3-4 clutch. The transmission control module (TCM ) provides current to PCS2, which controls the rate of pressure buildup of the 1-2-3-4 clutch, assuring a smooth transition to first range. The combination of the 1-2-3-4 clutch and the low and reverse clutch application produces first range operation.

After the shift to first range is complete, SS3 is de-energized followed closely by SS1 (timed to prevent SS3 from becoming "latched" down), allowing both valves to de-stroke. PCS2 is also de-energized, exhausting PCS2 signal pressure, allowing the pressure control valve 2 to de-stroke which exhausts PCS2 pressure. In the de-stroked position, shift valve 3 routes main pressure to the manual selector valve which directs the main pressure to the 1-2-3-4 clutch, keeping the 1-2-3-4 clutch applied. With the 1-2-3-4 clutch and the low and reverse clutch applied, the transmission stays in first range.

Control main pressure exhaust for pressure switch 2 is blocked by shift valve 2, keeping the switch turned on and providing feedback to the TCM that shift valve 2 is stroked. With shift valve 1 in the de-stroked position, the pressure feed to pressure switch 1 is eliminated and with the pressure exhausted, the pressure switch turns off, providing feedback that shift valve 1 is in the de-stroked position. With shift valve 3 de-stroked, the control main pressure to pressure switch 3 is exhausted and pressure switch 3 turns off, providing feedback that shift valve 3 is in the de-stroked position.

If electrical power is interrupted while the transmission is in first range, SS2 is de-energized. Normally closed PCS1 continues to block the exhaust of PCS1 signal pressure (signal pressure remains control main) which results in maximum PCS1 pressure being maintained. PCS1 pressure continues to be directed to shift valve 2, which stays stroked due to the "latching" effect of pressure on two different diameter lands and fluid continues to be directed to the low and reverse clutch, keeping the low and reverse clutch applied. Main pressure continues to be directed through shift valve 3 and the manual selector valve to the 1-2-3-4 clutch, keeping the 1-2-3-4 clutch applied. The combination of the 1-2-3-4 clutch and the low and reverse clutch application allows the transmission to stay in first range for limp home capability.

If electrical power is interrupted while the transmission is in first range, moving the manual selector valve to Neutral (N) will cut off main pressure to the 1-2-3-4 clutch and the clutch will be exhausted. The low and reverse clutch remains applied. Because only one clutch is applied, the transmission goes to neutral.

If electrical power is interrupted while the transmission is in first range, moving the manual selector valve to Reverse (R) cuts off main pressure to the 1-2-3-4 clutch, exhausting the 1-2-3-4 clutch. The manual selector valve directs main pressure through the TCC valve to the bottom of shift valve 2, de-stroking the valve and opening the path for main pressure to feed the low and reverse clutch, keeping the clutch applied. PCS1 control pressure is then directed to the 3rd, 5th, and reverse clutch, applying the clutch. The combination of the 3rd, 5th, and reverse clutch and the low and reverse clutch application produces Reverse (R) range operation, for limp home capability.

Important:  If the manual selector valve is put back in a forward range after reverse has been attained, the selector valve will direct fluid to the 1-2-3-4 clutch and shift valve 2 will stay de-stroked, directing fluid to the 3rd, 5th, and reverse clutch, resulting in third range operation.

If electrical power is interrupted while the transmission is in first range, resulting in only first, neutral, and reverse operation, the engine may be shut down and restarted to attain neutral, third, and reverse operation.