F 350 4WD Super Duty V10-6.8L VIN Z Bi-Fuel (2001)
Information Bus: Description and Operation
Principles and Operation - Module Communications Network
The vehicle has two module communication networks: the Standard Corporate Protocol (SCP), which is an unshielded twisted pair cable (data bus plus,
circuit 914 [TN/OG]) and data bus minus, (circuit 915 (PK/LB)); and the International Standards Organization (ISO) 9141 network, which is a single
wire network (circuit 70 (LB/WH)). The diagnostic tool can connect to both networks through the Data Link Connector (DLC). This makes diagnosis
and testing of these systems easier by allowing one smart tester to be able to diagnose and control any module on the two networks from one connector.
The DLC can be found under the instrument panel between the steering column and the radio.
The SCP communications network will remain operational even with the severing of one of the bus wires. Communications will also continue if one of
the bus wires is shorted to ground or voltage, or if some, but not all, termination resistors are lost.
The ISO 9141 communications network does not permit inter-module communication. When the diagnostic tool communicates to modules on the ISO
9141 communication network, the diagnostic tool must ask for all information; the modules cannot initiate communication.
The ISO 9141 communications network will not function if the wire is shorted to ground or battery voltage. Also, if one of the modules on the ISO 9141
communications network loses power or shorts internally, communications to that module will fail.
The four-wheel (standard for Excursion, optional for pickup) and rear wheel Anti-lock Brake System (ABS) module (optional on pickups only) is on the
ISO 9141 communication network. The module controls brake pressure to the wheels to keep the vehicle under control while braking.
The Electronic Crash Sensor (ECS) module is on early-build vehicles before 10/2/2000. The Restraint Control Module (RCM) is on late-build vehicles
after 10/2/2000. The ECS/RCM control the deployment of the air bags based on sensor input. The ECS/RCM are on the ISO 9141 network.
The Overhead Trip Computer (OTC) is connected to the ISO 9141 communication network. The OTC computes and displays in metric or English:
average fuel economy, distance to empty, and compass heading. Refer to Instrument Panel, Gauges and Warning Indicators.
The Generic Electronic Module (GEM) is on the ISO 9141 network. The GEM can control such systems as warning chimes, interior and exterior lamps,
keyless entry, wipers, power windows, and four wheel shift on the fly.
The parking aid module (if equipped) is connected to the ISO 9141 communication network. The module controls the sensors in the rear bumper that
detect close objects when the vehicle is in REVERSE.
The Powertrain Control Module (PCM) is on the SCP communication network. The PCM controls the engine for better fuel economy, emissions
control, and failure mode detection and storage.
The Auxiliary Powertrain Control Module (APCM) is on diesel engine equipped vehicles. The APCM is connected to the SCP communication network.
The APCM provides an operator interface to the drive-by-wire powertrain control system to effect charge protection, rpm control, and manual throttle
control between 1,300 and 2,500 rpm.
The Passive Anti-theft System (PATS) module is connected on the SCP communication network. The PATS module enables or disables the PCM to
deter drive-away theft.
