Description & Operation
Vehicle has 2 module communications networks. Standard Corporate Protocol (SCP) network communicates over a data bus, a pair of unshielded twisted wires (Tan/Orange wire and Pink/Black wire). SCP bus links the Powertrain Control Module (PCM) and Passive Anti-Theft System (PATS), and Data Link Connector (DLC). International Standards Organization (ISO) 9141 network communicates over a single wire (Light Blue/White wire) connecting Restraints Control Module (RCM), Generic Electronic Module (GEM), 4-Wheel Anti-Lock Brake System (4WABS) module, 4-Wheel Drive (4WD) control module, Central Security Module (CSM) and DLC.
SCP network is tolerant of electromagnetic interference. SCP network has ability to continue to function with one of its wires open, shorted to power, or shorted to ground. ISO 9141 network is unable to function if an open or short occurs in its wire. ISO 9141 network does not allow intermodule communication. Scan tool must initiate communication with modules on ISO 9141 network. Both networks can be accessed with scan tool at Data Link Connector (DLC). This article is used to diagnose SCP and ISO 9141 communications network circuit faults. For module locations, see Fig 1 and/or COMPONENT LOCATIONS .