Overdrive (4, 5, 6) Clutch Hydraulic Circuits (Released)
When the overdrive (4, 5, 6) clutch is released in 1st gear above 8 km/h (5 mph), 2nd and 3rd gears, solenoid pressure from SSD is removed from the low reverse/456 regulator and latch valves which positions the valves to block line pressure and release the overdrive (4, 5, 6) clutch.
When the overdrive (4, 5, 6) clutch is released in 1st gear above 8 km/h (5 mph), 2nd and 3rd gears, exhaust backfill supplied to the low reverse/456 clutch regulator valve and the clutch control bypass valve by the manual valve through the EXH BF circuit is directed to the low reverses latch valve, low/reverse clutch and overdrive (4, 5, 6) clutch to fill the unused circuits with unpressurized transmission fluid.
When the overdrive (4, 5, 6) clutch is released in PARK, REVERSE, NEUTRAL and 1st gear below 8 km/h (5 mph), the low reverse/456 regulator valve supplies regulated pressure to the clutch control bypass valve through the CBR1/C456 circuit. With ON/OFF SSE in the ON position, the regulated pressure is directed to the low/reverse clutch.
For details on valve body hydraulic circuits and solenoid operation. For additional information, refer to: Transmission Description - System Operation and Component Description .