5TH Gear Failsafe

Transaxle Operation
Transaxle Operation Overview Transaxle Operation Overview
Park Position
Reverse Position
Neutral Position
1st Gear Above 6 km/h (4 mph)
2nd Gear
3rd Gear
4th Gear
5th Gear
6th Gear Torque Converter Clutch (TCC) Applied
5th Gear Failsafe (below)

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 and LPC solenoids. The uncontrolled solenoids default to their normal states. SSB, SSD and the LPC 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 (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 solenoid through the VBS LINE circuit. In 5th gear failsafe, full solenoid pressure is supplied by the LPC 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 control valve through the CONV FD hydraulic circuit.
- When the TCC is released, CONV FD pressure is directed to the TCC RELEASE circuit by the TCC control valve. Pressure from the TCC RELEASE circuit releases the TCC.
- Fluid from the TCC RELEASE circuit returns to the TCC control valve through the TCC APPLY circuit.

Cooler and lubrication hydraulic circuits:

- The TCC control valve directs fluid from the TCC APPLY circuit (return circuit from the torque converter when the TCC 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 solenoid applies maximum solenoid output pressure to the main pressure regulator valve through the VBS LINE hydraulic circuit. The LPC solenoid defaults to maximum output to provide maximum line pressure.
- SSD applies maximum solenoid pressure to the low reverse/456 clutch regulator and latch valves to apply the O/D (4, 5, 6) clutch.
- SSB 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 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 (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 regulator valve, DRIVE 2 circuit, DRIVE 2/C35R FD shuttle ball and DRIVE 2/C35R FD circuit. SSB 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