Circuit Description
WARNING: This page is about a different car, the 2004 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
The Controller Area Network (CAN) serial data line is a high speed serial data bus used to communicate information between the engine control module (ECM) and the transmission control module (TCM). Typical data-transmission speeds must be high enough to ensure that the required real-time response is maintained.
The CAN serial data line does not communicate with the scan tool via the DLC. CAN serial data information is interpreted by the ECM and transmitted to the serial data line by the ECM.