Description & Operation

WARNING: This page is about a different car, the 2001 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.

Powertrain Control Module (PCM), instrument cluster and Natural Gas Vehicle Module (NGVM) are connected to multiplex communications network through a pair of twisted wires or bus. Bus network is also referred to as Standard Corporate Protocol (SCP). Bus consists of a (+) circuit and a (-) circuit. Generic Electronic Module (GEM)/Central Timer Module (CTM), Remote Anti-Theft Personality (RAP) module/Central Security Module (CSM), Restraint Control Module (RCM) and 4-Wheel Anti-Lock Brake System (4WABS) module are connected to the International Standards Organization (ISO) diagnostic communications network through a single wire. This article is used to diagnose bus and ISO communications network circuit faults. For module locations, see COMPONENT LOCATIONS .