Fluid pressure, from the automatic transmission secondary fluid pump assembly, unseats the ball check valve to
allow fluid flow to the manual valve, where it is directed to the overrun clutch hydraulic circuit. The check
valve prevents fluid, from the main transmission oil pump, from flowing into the secondary fluid pump.
Torque Converter Clutch
TCC Solenoid Valve
Under normal operating conditions, in Overdrive Range-Third Gear, the PCM keeps the normally open TCC
solenoid valve de-energized. Converter feed fluid exhausts through the open solenoid, and spring force keeps
the converter clutch apply valve in the release position. However, at speeds above approximately 121 km/h (75
mph), with the transmission still in third gear, the PCM will command TCC apply in third gear. Refer to
Overdrive Range, Fourth Gear - Torque Converter Clutch (TCC) Applied for more information on TCC
apply.
2004 Hummer H2
2004 TRANSMISSION/TRANSAXLE Automatic Transmission - Overhaul - 4L60-E/4L65-E