Circuit/System Description
WARNING: This page is about a different car, the 2007 Suzuki XL7. However, it is still accessible from the selected car via links, so may be relevant.
The transmission control module (TCM) controls the torque converter clutch (TCC) lock up pressure control solenoid valve. The solenoid directs the hydraulic fluid for TCC apply and release. When the TCC is released, the engine is coupled by fluid to the transmission.