Catera V6-3.0L VIN R (1997)
Information Bus: Description and Operation
Serial Data
The Catera uses International Standards Organization (ISO) serial data and communicates with the scan tool on Data Link Connector (DLC) pin-7. Most
other GM OBD II vehicles use Class 2 serial data on DLC pin-2. Both the Engine Control Module (ECM) and the Traction Control Module (TCM)
communicate with the scan tool by using the ISO serial data circuit.