Manual First - First Gear

Manual First - First Gear (From Manual Second - Second Gear):

MANUAL FIRST - FIRST GEAR

A manual 2-1 downshift is initiated by moving the gear selector lever to the Manual First (1) position. However, the transaxle will not downshift into First gear until vehicle speed is below approximately 60 km/h (37 mph). At higher vehicle speeds the PCM will keep 1-2 shift solenoid de-energized (OFF) and the transaxle will operate in Manual First - Second Gear. In Manual First the transaxle is electronically prevented from upshifting into Third or Fourth gears under any conditions. Also, the coast clutch remains applied, as in Manual Third and Manual Second, and provides engine compression braking in First and Second gears.

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

Pressure Switch Assembly: LO fluid pressure is routed to the Pressure Switch Assembly (PSA) and the PSA signals the PCM that the manual valve is in the Manual First position.

#1 Checkball (LO/PRN): LO fluid pressure seats the #1 checkball against the PRN fluid circuit and fills the LO/PRN fluid circuit. LO/PRN fluid is routed to the 1-2 shift valve.

1-2 Shift Solenoid: 1-2 Shift solenoid is energized by the PCM when vehicle speed is below approximately 30 to 35 mph. 1-2 Signal fluid is blocked from exhausting through the solenoid.

1-2 Shift Valve: 1-2 Signal fluid pressure shifts the valve into the downshifted position against spring force and the following changes occur:

^ The 2-3 drive fluid circuit is open to an exhaust past the valve.
^ Intermediate band fluid is exhausted past the valve.
^ LO/PRN fluid is routed into the lo band fluid circuit.

SECOND CLUTCH RELEASES

Second Clutch: 2nd clutch fluid exhausts from the clutch piston and through the 2-3 drive fluid circuit. This releases the 2nd clutch and the transaxle operates in First gear.

1-2 Accumulator: 2nd clutch feed fluid exhausts from the 1-2 accumulator, exhausts past the #2 checkball and through the 2-3 drive fluid circuit. 1-2 accumulator feed fluid fills the 1-2 accumulator as 2nd clutch fluid exhausts.

1-2/3-4 Accumulator Valve: The accumulator valve regulates line pressure into the 1-2/3-4 accumulator fluid circuit to fill the 1-2 accumulator. This regulation is basically controlled by torque signal fluid pressure. Accumulator fluid pressure is regulated to a higher pressure with greater torque signal fluid pressure.

TCC Control Solenoid: Filtered 2-3 drive fluid exhausts from the solenoid and through the 2-3 drive fluid circuit.


INTERMEDIATE BAND RELEASES

Intermediate/4th Servo: Intermediate Band fluid exhausts from the servo piston, spring force moves the piston and apply pin and the intermediate/4th band releases. However, the intermediate/4th band remains applied in Manual First - Second Gear to achieve engine compression braking.


LO/REVERSE BAND APPLIES

Lo/Reverse Servo: Lo/band fluid pressure is routed to the inner area of the lo/reverse servo to apply the lo/reverse band. The Lo/Reverse band provides engine compression braking when the throttle is released in Manual First - First Gear.

Note: Manual First - Third Gear is also possible at high speeds as a safety feature.