Internal Components
WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Several components of the 1000 Series electrical control system are located within the transmission as part of the main control valve body. These components include 3 types of solenoids for controlling the hydraulic action of the valves. They include the PSM and an internal wiring harness that links the internal components with the TCM.