Automatic Transaxle Diagnosis - 4T80-E: Operation: Notes

Each solenoid either holds hydraulic pressure (solenoid on) or releases hydraulic pressure (solenoid off). This action controls shift valves inside valve body. By switching one or both solenoids on or off, different combinations of clutches, sprags and bands are operated. See CLUTCH & BAND APPLICATION CHART (4T80-E)  under ELECTRONIC TESTING.