Hydraulic Control System

The hydraulics of the transaxle provide:
- Manual shift lever select function
- Main line pressure regulation
- Torque converter flow control
- Transaxle oil cooler flow control

Oil flow to the friction elements is controlled directly by four solenoid valves. The hydraulics also include a logic-controlled solenoid switch valve. It locks out the 1st gear reaction element with the application of 2nd, direct, or overdrive gear elements. It also redirects the 1st gear solenoid output so that it can control torque converter clutch operation. To regain access to 1st gear, a special sequence of solenoid commands must be used to unlock and move the solenoid switch valve. This precludes any application of the 1st gear reaction element with other elements applied. It also allows one solenoid to control two friction elements.

Small, high-rate accumulators are provided in each controlled friction element circuit. These serve to absorb the pressure responses, and allow the controls to read and respond to changes that are occurring.