Part 4
Transaxle Operation
Transaxle Operation Overview
Torque converter circuits:
- When the torque converter is applied, line pressure from the manual valve is directed to the TCC (Torque Converter Clutch) regulator valve by the clutch control bypass valve through the DRIVE 2 circuit. The TCC (Torque Converter Clutch) solenoid supplies varying solenoid pressure to the TCC (Torque Converter Clutch) regulator valve and the TCC (Torque Converter Clutch) control valve to position the valves to apply the TCC (Torque Converter Clutch).
- As the TCC (Torque Converter Clutch) regulator valve moves, it supplies the TCC (Torque Converter Clutch) control valve with regulated line pressure through the REG APPLY circuit. The TCC (Torque Converter Clutch) control valve directs the REG APPLY circuit to the TCC APPLY circuit to apply the TCC (Torque Converter Clutch).
- Pressure from the torque converter returns to the TCC (Torque Converter Clutch) control valve through the TCC RELEASE circuit.
Cooler and lubrication hydraulic circuits:
- Regulated line pressure from the main pressure regulator valve is directed to the TCC (Torque Converter Clutch) control valve through the CONV FD hydraulic circuit. When the TCC (Torque Converter Clutch) is applied, CONV FD pressure supplies the COOLER FD circuit which circulates through the transmission fluid cooler or the thermal bypass valve.
- In the COOLER FD circuit, transmission fluid flows through the transmission fluid cooler or the thermal bypass valve to the LUBE circuit in the input shaft to supply lubrication to the transaxle.
Solenoid hydraulic circuits:
- The LPC (Line Pressure Control) solenoid applies varying pressure to the main pressure regulator valve through the VBS LINE hydraulic circuit. The LPC (Line Pressure Control) solenoid regulates line pressure by controlling the position of the main pressure regulator valve.
- SSD (Shift Solenoid D) applies pressure to the low reverse/456 regulator and latch valves to apply the O/D (Overdrive) (4, 5, 6) clutch.
- SSB (Shift Solenoid B) releases pressure to the 35R regulator and latch valves to release the direct (3, 5, R) clutch.
- SSC (Shift Solenoid C) applies pressure to the 26 regulator and latch valves to apply the direct (2, 6) clutch.
- The TCC (Torque Converter Clutch) solenoid applies pressure to the TCC (Torque Converter Clutch) control valve and the TCC (Torque Converter Clutch) regulator valve to apply the TCC (Torque Converter Clutch).
Clutch hydraulic circuits:
- Line pressure from the pump is supplied to the low reverse/456 regulator valve. SSD (Shift Solenoid D) supplies varying solenoid pressure to the low reverse/456 regulator and latch valves. As the regulator valve moves, it supplies the clutch control bypass valve and low reverse/456 latch valve with regulated line pressure through the CBR1/C456 circuit. The low reverse/456 latch valve directs the regulated line pressure to the opposite side of the low reverse/456 regulator valve through the CBR1/C456 FDBK circuit for gradual clutch engagement.
- Regulated line pressure at the clutch control bypass valve in the CBR1/C456 circuit is directed to the O/D (Overdrive) (4, 5, 6) clutch through the C456 circuit to apply the clutch.
- Regulated line pressure in the C456 circuit also supplies the latch pressure for the clutch control bypass valve.
- Solenoid pressure from SSB (Shift Solenoid B) is removed from the 35R regulator and latch valves which positions the valves to block line pressure and release the direct (3, 5, R) clutch.
- Line pressure is supplied to the 26 regulator valve by the manual valve in the DRIVE and LOW positions. To apply the intermediate (2, 6) clutch, SSC (Shift Solenoid C) supplies varying solenoid pressure to the 26 regulator and latch valves. As the regulator valve moves, it supplies the intermediate (2, 6) clutch and 26 latch valve with regulated line pressure through the CB26 circuit. The 26 latch valve directs the regulated line pressure to the opposite side of the regulator valve through the CB26 FDBK circuit for gradual intermediate (2, 6) clutch engagement.
For additional hydraulic circuit and information, refer to Hydraulic Circuits Hydraulic Circuits.
Electrical Operation
Solenoid operation:
6th Gear TCC (Torque Converter Clutch) Applied Solenoid Operation Chart
NC = Normally closed
NH = Normally high
NL = Normally low
Manual LOW Position and 1st Gear Below 8 km/h (5 mph) Solenoid Operation Chart
NOTE: The transaxle operates differently in first gear above and below 8 km/h (5 mph). For transaxle operation above 8 km/h (5 mph), refer to 1st Gear Above 8 km/h (5 mph).
Mechanical Operation
Apply components:
- Forward (1, 2, 3, 4) clutch
- Low/reverse clutch
- Low OWC (One-Way Clutch)
Planetary Gearset Operation
Front planetary gearset driven components:
- Ring gear
- Planetary carrier
Center planetary gearset driven components:
- Sun gear
- Planetary carrier
Rear planetary gearset driven components:
- None
Front planetary gearset held components:
- Sun gear
Center planetary gearset held components:
- Ring gear
Rear planetary gearset held components:
- Rear planetary carrier (does not contribute to power flow)
Manual LOW Position and 1st Gear Below 8 km/h (5 mph) Clutch Application Chart
For component information, refer to Mechanical Components and Functions Mechanical Components and Functions.
Power Flow
Hydraulic Operation
Line pressure hydraulic circuits:
- Line pressure from the pump is supplied to the main pressure regulator valve, low reverse/456 regulator valve, manual valve, solenoid regulator valve and control pressure regulator.
- Line pressure is controlled by the position of the main pressure regulator valve.
- The position of the main pressure regulator valve is controlled by varying pressure from the LPC (Line Pressure Control) solenoid through the VBS LINE circuit.
Torque converter circuits:
- Regulated line pressure from the main pressure regulator valve is directed to the TCC (Torque Converter Clutch) control valve through the CONV FD hydraulic circuit.
- When the TCC (Torque Converter Clutch) is released, CONV FD pressure is directed to the TCC RELEASE circuit by the TCC (Torque Converter Clutch) control valve. Pressure from the TCC RELEASE circuit releases the TCC (Torque Converter Clutch).
- Fluid from the TCC RELEASE returns to the TCC (Torque Converter Clutch) control valve through the TCC APPLY circuit.
Cooler and lubrication hydraulic circuits:
- The TCC (Torque Converter Clutch) control valve directs fluid from the TCC APPLY circuit (return circuit from the torque converter when the TCC (Torque Converter Clutch) is released) to the COOLER FD circuit.
- In the COOLER FD circuit, transmission fluid flows through the transmission fluid cooler or the thermal bypass valve to the LUBE circuit in the input shaft to supply lubrication to the transaxle.
Solenoid hydraulic circuits:
- The LPC (Line Pressure Control) solenoid applies varying pressure to the main pressure regulator valve through the VBS LINE hydraulic circuit. The LPC (Line Pressure Control) solenoid regulates line pressure by controlling the position of the main pressure regulator valve.
- SSA (Shift Solenoid A) applies pressure to the 1234 regulator and latch valves to apply the forward (1, 2, 3, 4) clutch.
- SSD (Shift Solenoid D) applies pressure to the low reverse/456 regulator and latch valves to apply the low/reverse clutch.
- SSE (Shift Solenoid E) applies pressure to the clutch control bypass valve to position the valve to direct regulated line pressure in the CBR1/C456 circuit to the low/reverse clutch.
Clutch hydraulic circuits:
- Line pressure is supplied to the 1234 regulator valve by the manual valve in the DRIVE and LOW position. To apply the forward (1, 2, 3, 4) clutch, SSA (Shift Solenoid A) supplies varying solenoid pressure to the 1234 regulator and latch valves. As the 1234 regulator valve moves, it supplies the forward (1, 2, 3, 4) clutch and 1234 latch valve with regulated line pressure through the C1234 circuit. The latch valve directs the regulated line pressure to the opposite side of the regulator valve through the C1234 FDBK circuit for gradual forward (1, 2, 3, 4) clutch engagement.
- Line pressure from the pump is supplied to the low reverse/456 regulator valve. To apply the low/reverse clutch, SSD (Shift Solenoid D) supplies varying solenoid pressure to the low reverse/456 regulator and latch valves. As the regulator valve moves, it supplies the clutch control bypass valve and low reverse/456 latch valve with regulated line pressure through the CBR1/C456 circuit. The low reverse/456 latch valve directs the regulated line pressure to the opposite side of the low reverse/456 regulator valve through the CBR1/C456 FDBK circuit for gradual low/reverse clutch engagement.
- Regulated line pressure at the clutch control bypass valve in the CBR1/C456 circuit is directed to the low/reverse clutch through the CBR1 circuit to apply the clutch.
For additional hydraulic circuit and information, refer to Hydraulic Circuits Hydraulic Circuits.
Electrical Operation
Solenoid operation:
Manual LOW Position and 1st Gear Below 8 km/h (5 mph) Solenoid Operation Chart
NC = Normally closed
NH = Normally high
NL = Normally low
5th Gear Failsafe
5th Gear Failsafe Description
When the transaxle has an electrical, hydraulic or mechanical failure, the PCM removes ground (control) from the shift, TCC (Torque Converter Clutch) and LPC (Line Pressure Control) solenoids. The uncontrolled solenoids default to their normal states. SSB (Shift Solenoid B) , SSD (Shift Solenoid D) and the LPC (Line Pressure Control) solenoid are normally high solenoids which means in their normal state, they provide high pressure to the valves they control. This provides only 5th gear with maximum line pressure.
Mechanical Operation
Apply components:
- O/D (Overdrive) (4, 5, 6) clutch
- Direct (3, 5, R) clutch
Planetary Gearset Operation
Front planetary gearset driven components:
- Planetary carrier
Center planetary gearset driven components:
- Sun gear (does not contribute to power flow)
Rear planetary gearset driven components:
- Sun gear
- Planetary carrier
Front planetary gearset held components:
- None
Center planetary gearset held components:
- None
Rear planetary gearset held components:
- None
5th Gear Failsafe Clutch Application Chart
For component information, refer to Mechanical Components and Functions Mechanical Components and Functions.
Power Flow
Hydraulic Operation
Line pressure hydraulic circuits:
- Line pressure from the pump is supplied to the main pressure regulator valve, low reverse/456 regulator valve, manual valve, solenoid regulator valve and control pressure regulator.
- Line pressure is controlled by the position of the main pressure regulator valve.
- The position of the main pressure regulator valve is controlled by varying pressure from the LPC (Line Pressure Control) solenoid through the VBS LINE circuit. In 5th gear failsafe, full solenoid pressure is supplied by the LPC (Line Pressure Control) solenoid to the main pressure regulator valve for maximum line pressure.
Torque converter circuits:
- Pressure from the main pressure regulator valve is directed to the TCC (Torque Converter Clutch) control valve through the CONV FD hydraulic circuit.
- When the TCC (Torque Converter Clutch) is released, CONV FD pressure is directed to the TCC RELEASE circuit by the TCC (Torque Converter Clutch) control valve. Pressure from the TCC RELEASE circuit releases the TCC (Torque Converter Clutch).
- Fluid from the TCC RELEASE circuit returns to the TCC (Torque Converter Clutch) control valve through the TCC APPLY circuit.
Cooler and lubrication hydraulic circuits:
- The TCC (Torque Converter Clutch) control valve directs fluid from the TCC APPLY circuit (return circuit from the torque converter when the TCC (Torque Converter Clutch) is released) to the COOLER FD circuit.
- In the COOLER FD circuit, transmission fluid flows through the transmission fluid cooler or the thermal bypass valve to the LUBE circuit in the input shaft to supply lubrication to the transaxle.
Solenoid hydraulic circuits:
- The LPC (Line Pressure Control) solenoid applies maximum solenoid output pressure to the main pressure regulator valve through the VBS LINE hydraulic circuit. The LPC (Line Pressure Control) solenoid defaults to maximum output to provide maximum line pressure.
- SSD (Shift Solenoid D) applies maximum solenoid pressure to the low reverse/456 clutch regulator and latch valves to apply the O/D (Overdrive) (4, 5, 6) clutch.
- SSB (Shift Solenoid B) applies maximum solenoid pressure to the 35R clutch regulator and latch valves to apply the direct (3, 5, R) clutch.
Clutch hydraulic circuits:
- Line pressure from the pump is supplied to the low reverse/456 regulator valve. SSD (Shift Solenoid D) supplies maximum solenoid pressure to the low reverse/456 regulator and latch valves to provide full line pressure in the CBR1/C456 circuit.
- Maximum line pressure at the clutch control bypass valve in the CBR1/C456 circuit is directed to the O/D (Overdrive) (4, 5, 6) clutch through the C456 circuit to apply the clutch.
- Pressure in the C456 also supplies the latch pressure for the clutch control bypass valve.
- Line pressure from the pump is directed to the clutch control bypass valve by the manual valve through the DRIVE hydraulic circuit. The clutch control bypass valve directs the pressure to the 35R regulator valve through the TCC (Torque Converter Clutch) regulator valve, DRIVE 2 circuit, DRIVE 2/C35R FD shuttle ball and DRIVE 2/C35R FD circuit. SSB (Shift Solenoid B) applies maximum solenoid pressure to the 35R regulator and latch valves to provide full line pressure to the direct (3, 5, R) clutch.
For additional hydraulic circuit and information, refer to Hydraulic Circuits Hydraulic Circuits.
Electrical Operation
Solenoid operation:
5th Gear Failsafe Solenoid Operation Chart
NC = Normally closed
NH = Normally high
NL = Normally low
