Hydraulic Control System

HYDRAULIC SYSTEM CONTROLS
- Manual Shift Lever Select Function
- Main Line Pressure Regulation
- Torque Converter Flow Control
- Cooler Flow Control

Flow to the friction elements is controlled directly by four solenoid valves.

TORQUE CONVERTER CLUTCH CONTROL VALVE
The hydraulics also include a unique logic-controlled "solenoid torque converter clutch control valve". This valve 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.

REGAINING ACCESS TO 1ST GEAR
To regain access to 1st gear, a special sequence of solenoid commands must be used to unlock and move the solenoid torque converter clutch control valve.

- This precludes any application of the first gear reaction element with other elements applied.

- It also allows one solenoid to control two friction elements.

HIGH-RATE ACCUMULATORS
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.