Circuit Description
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
Engine torque information is sent to the transmission control module (TCM) by the engine control module (ECM) through the controller area network (CAN). A two-wire circuit is used to communicate data between the ECM and TCM, CAN H and CAN L. A fault in the CAN will not cause DTC P2637 to set by itself. If a communication fault occurs, other DTCs will set before P2637.
When the ECM sends the TCM an invalid engine torque, DTC P2637 sets. DTC P2637 is a type A DTC.