Description & Operation
WARNING: This page is about a different car, the 1998 Lincoln Mark VIII. However, it is still accessible from the selected car via links, so may be relevant.
The module communications network provides the ability for 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 network is also referred to as Standard Corporate Protocol (SCP). The BUS consists of a (+) circuit No. 914 and a (-) circuit No. 915. The BUS is routed throughout the vehicle to each module except the Passenger's Seat Module (PSM). The PSM does not use the BUS to communicate with other modules. The PSM is connected to the International Standards Organization (ISO) 9141 diagnostic communications network through a single wire (circuit No. 70). This wire provides a means for the scan tester to communicate with the PSM by using the DLC. Both ISO and BUS 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 table.
COMPONENT LOCATIONS
| Component |
Location |
| Anti-Lock Brake System ABS) Module |
Left Front Corner Of Engine Compartment |
| Cellular Phone Module (CPM) |
In Trunk, On Panel Below Rear Window |
| Data Link Connector (DLC) |
Below Driver's Side Of Instrument Panel, To Right Of Steering Column |
| Driver's Door Module (DDM) |
Inside Driver's Door |
| Driver's Seat Module (DSM) |
Under Driver's Seat |
| Electronic Automatic Temperature Control (EATC) Module |
Behind Center Of Instrument Panel, Below Radio |
| Hybrid Electronic Cluster (HEC) |
Center Of Driver's Side Instrument Panel |
| Message Center Module (MCM) |
Center Of Instrument Panel, Above Radio |
| Passenger's Seat Module (PSM) |
Under Passenger's Side Front Seat |
| Powertrain Control Module (PCM) |
Below Driver's Side Of Instrument Panel, To Left Of Steering Column |
| Steering Column/Ignition/Lighting SCIL) Module |
Behind Right Side Of Instrument Panel, Right Of Glove Box |
| Variable Load Control Module (VLCM) |
Behind Right Front Fender In Front Of Wheel Opening |