Use the Manual 3-2 downshift in order to provide increased
engine braking over Manual Third. Move the shift selector from the Manual
Third position to the Manual Second position. You can select Manual Second
at any vehicle speed or from any gear range in order to downshift the transmission
into second gear.
Manual Valve: In the Manual Second range, line pressure from the pressure regulator
valve is directed as D321, D21 and Drive fluid pressures. The D321 fluid pressure
is directed to the overrun clutch. The D21 fluid pressure is directed to
the 2-3 shift valve. The Drive fluid is directed to the automatic
transmission fluid pressure (TFP) manual valve position switch assembly,
the forward clutch, the 1-2 shift valve, and the accumulator valve.
The manual valve shuts off PRND4 fluid pressure to the TFP manual valve
position switch. The manual valve also shuts off PRND43 fluid pressure
in order to assist the manual 2-1 band servo spring. This allows
the manual 2-1 band to apply.
Automatic Transmission Fluid Pressure (TFP) Manual Valve Position Switch
Assembly: The PRND43 fluid exhausts at the manual valve. The TFP manual valve
position switch signals the PCM that the transmission is in Manual Second.
1-2 Shift Solenoid (1-2 SS) Valve: When the 1-2 SS valve is de-energized, 1-2 signal
pressure exhausts through the solenoid. This allows spring force to move the
1-2 shift valve to the extreme right.
2-3 Shift Solenoid (2-3 SS) Valve: When the 2-3 SS valve is de-energized, 2-3 signal
pressure exhausts through the solenoid. This forces the 2-3 shift valve
to the extreme right by spring force and by D21 fluid pressure from the
manual valve.
1-2 Shift Valve: Spring force holds the 1-2 shift valve to the extreme right.
Drive fluid pressure from the manual valve is changed into the 2-3 drive
fluid pressure at the 1-2 shift valve. This pressure is directed
to the 2-3 shift valve, the TCC PWM solenoid valve, and the
intermediate (second) clutch.
2-3 Shift Valve: Spring force and the D21 fluid pressure from the manual valve hold
the 2-3 shift valve to the extreme right. The 2-3 drive pressure
from the 1-2 shift valve changes into Front Band Apply (FBA) and
is directed to the manual 2-1 band servo.
3-4 Shift Valve: Spring force holds the 3-4 shift valve to the extreme right.
Manual 2-1 Band Servo: Front Band Apply (FBA) fluid pressure from the 2-3 shift
valve seats the #3 checkball. This causes the fluid to flow through
an orifice and into the manual 2-1 band servo piston housing,
which applies the manual 2-1 band servo and band.
Forward Clutch: Drive fluid pressure from the manual valve, applies the forward
clutch.
Intermediate (Second) Clutch: The Intermediate (Second) Clutch is applied by second fluid pressure
from the 1-2 shift valve. The 2-3 drive fluid pressure from
the 1-2 shift valve seats the #4 checkball in the case, causing
the fluid to flow through two orifices. The 2-3 drive fluid pressure
changes to Second apply fluid pressure at the orifices. The Second apply
fluid flows into the center support, which applies the intermediate (second)
clutch.
Overrun Clutch: The D321 fluid pressure from the manual valve seats the #1 checkball
in the case. This causes the fluid to flow through an orifice, where the D321
fluid pressure changes into overrun fluid pressure. The overrun fluid pressure
flows through the case and the pump housing, and into the overrun clutch
housing, which applies the overrun clutch. The overdrive roller clutch becomes
ineffective and provides vehicle engine compression braking.
Manual Second Gear