3-2 Downshift (Valves In Second Gear Position)
3-2 Downshift (Valves In Second Gear Position):
3-2 DOWNSHIFT (VALVES IN SECOND GEAR)
To obtain the 3-2 downshift, the Powertrain Control Module (PCM) receives an input signal from the Throttle Position Sensor (TPS) at increased throttle openings which causes it to de-energize solenoid "B".
- Solenoid "A": De-energized, spring force holds 1-2 shift valve to extreme right.
- Solenoid "B": De-energized, signal "B" pressure exhausts at the solenoid which allows spring force to move the 2-3 shift valve to the extreme right.
- 2-3 Shift Valve: The third clutch feed pressure from the 2-3 shift valve is shut off and an exhaust port is opened at the 2-3 shift valve to exhaust third clutch fluid leaving the third clutch accumulator. This causes the direct clutch to release which shifts the transmission into second gear.
- Direct Clutch: Exhausting third clutch fluid unseats the #8 checkball which allows for a rapid exhausting of the third clutch apply fluid at the 2-3 shift valve.
- Third Clutch Accumulator: Exhausting third clutch accumulator fluid also exhausts through the unseated #8 check valve and exhausts at the 2-3 shift valve.