TRD Link: Description
WARNING: This page is about a different car, the 2005 Dodge Stratus and 2005 Chrysler Sebring. However, it is still accessible from the selected car via links, so may be relevant.
The Torque Reduction Link (TRD) is a wire between the PCM and TCM that is used by the TCM to request torque management. Torque management controls or reduces torque output of the engine during certain shift sequences, reducing torque applied to the transaxle clutches.