DTC P1571: Traction Control Torque Request Circuit: Description
WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
Traction control is simultaneously controlled by the Electronic Brake and Traction Control Module (EBTCM) and the Engine Control Module (ECM). The ECM sends engine torque data via serial data communications to the EBTCM. The EBTCM and ECM use this message to determine traction control operation.