Description & Operation

Vehicle has 2 module communications networks. The Powertrain Control Module (PCM), Anti-Lock Brake System (ABS) control module, and Alternative Fuel Control Module (AFCM) are connected to the multiplex communications network through a pair of twisted wires or bus. The bus network is also referred to as Standard Corporate Protocol (SCP). The bus consists of (+) circuit and a (-) circuit. The ABS control module is also connected to the ISO 9141 diagnostic communications network through a single wire along with the air bag control module. Both networks are connected to the Data Link Connector (DLC). This article is used to diagnose bus and ISO communications network circuit faults. For module locations, see COMPONENT LOCATIONS  .