Description & Operation
Vehicle has 2 module communications networks. The Powertrain Control Module (PCM) is connected to the Standard Corporate Protocol (SCP) multiplex communications network through a pair of twisted wires or BUS. The BUS consists of a positive (+) circuit and negative (-) circuit (circuits No. 914 and 915).
The air bag diagnostic monitor and all other optional modules, the Generic Electronic Module (GEM), Central Security Module (CSM) and 4-Wheel Anti-Lock Brake System (4WABS) module, are connected to the International Standards Organization (ISO) 9141 diagnostic communications network through a single wire (circuit No. 70). Both networks are connected to the Data Link Connector (DLC). See Fig 1.