Lumina V6-3.8L VIN K (1998)
Shift Solenoid: Description and Operation
4T60-E Automatic Transaxle
SHIFT CONTROLS
The Hydra-matic 4T60-E uses two ON/OFF shift solenoid valves with a 2-port design that provides for all forward gear ranges. These shift solenoid
valves work together in a combination of ON or OFF sequences to direct fluid pressures to the various shift valves and apply components. The
following table shows the solenoid state for each gear range:
1-2 SHIFT SOLENOID VALVE
The PCM controls the ground for the 1-2 Shift Solenoid (1-2 SS) valve, thereby commanding the solenoid ON or OFF according to transmission and
vehicle operation. When the solenoid is OFF, filtered line pressure that is fed to the solenoid will cease. When energized (ON), the exhaust port is
blocked, stopping the exhaust of line pressure through the solenoid. Pressure on the end of the 1-2 shift solenoid valve moves the valve against a
spring force, sending line pressure into the 1-2 shift solenoid fluid passage to the 3-4 shift valve.
2-3 SHIFT SOLENOID VALVE
The 2-3 Shift Solenoid (2-3 SS) valve functions identically to the 1-2 Shift Solenoid valve in that the PCM controls the ground to the solenoid,
commanding it ON or OFF. When the solenoid is OFF, filtered line pressure feeding the solenoid will cease. When energized (ON), the exhaust port is
blocked, stopping the exhaust of line pressure and directing it into the 2-3 shift solenoid fluid passage. The 2-3 shift solenoid fluid pressure then feeds
to the 4-3 manual downshift valve and the 3-2 manual downshift valve.
