Description & Operation: Notes

The module communications network provides the ability for a module-to-module communication by sharing inputs and outputs instead of each component having an input and output wired directly to each module. A BUS which consists of a pair of twisted wires is used to transfer information between each module. The BUS consists of a (+) circuit No. 914 and a (-) circuit No. 915. The BUS is routed throughout the vehicle to Powertrain Control Module (PCM), Electronic Automatic Temperature Control (EATC) module, and Natural Gas Vehicle (NGV) module (if equipped). See Fig 1. Terminal No. 7 (Light Blue/White wire) on DLC is routed through vehicle to Lighting Control Module (LCM), Anti-Lock Brake System (ABS) Module, Air Bag Diagnostic Monitor, and Driver's Door Module (DDM). This wire is referred to as the ISO 9141 communication link circuit No. 70 and provides a means for the scan tester to communicate with these modules using the DLC. For module locations, see COMPONENT LOCATIONS TABLE. In the event that a system failure exists, a Diagnostic Trouble Code (DTC) will be stored in the module. A New Generation Star (NGS) scan tester and Data Link Connector (DLC) may be used for retrieving and clearing DTCs from the module. DTC may be used for system diagnosis.

Fig 1: Locating Module Communication Network Components

Courtesy of FORD MOTOR CO.