Crown Victoria V8-4.6L Flex Fuel (2008)
while the HS-CAN and SCP network allow multiple modules to communicate (transfer data) with each other on a common network.
HS-CAN Operation
The HS-CAN uses an unshielded twisted pair cable, data bus (+) and data bus (-) circuits. In addition to scan tool communication, this network allows
sharing of information between all modules on the network.
The HS-CAN is a high speed communication network used for the following modules:
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ABS module
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Vehicle dynamics module (VDM)
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Fire suppression module (police only, if equipped)
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Instrument cluster
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PCM
ISO Network Operation
The ISO communication network is a single wire network, used for diagnostic purposes only.
The ISO communication network is used for the following modules:
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Fire suppression module (police only, if equipped)
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Restraints control module (RCM)
Standard Corporate Protocol (SCP) Communication Network
The SCP network has an unshielded twisted pair cable, data bus (+) and data bus (-) circuits. In addition to scan tool communication, this network
allows sharing of information between all modules on the network.
The SCP communication network is used for the following modules:
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Driver door module (DDM) (if equipped)
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Electronic automatic temperature control (EATC) module (if equipped)
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Instrument cluster (gateway module)
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Lighting control module (LCM)
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Overhead console module (OHC) (if equipped)
Network Termination
The HS-CAN uses a network termination circuit to improve communication reliability. The network termination of the HS-CAN bus takes place inside
the termination modules by termination resistors. Termination modules are located at either end of the bus network. As network messages are
broadcast, in the form of voltage signals, the network voltage signals are stabilized by the termination resistors. Each termination module has a 120
ohm resistor across the positive and negative bus connection in the termination module. With 2 termination modules on each network, and the 120
ohm resistors located in a parallel circuit configuration, the total network impedance (resistance) is 60 ohms.
Network termination improves bus message reliability by:
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stabilizing bus voltage.
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eliminating electrical interference.
Gateway Module
The instrument cluster is the gateway module, translating HS-CAN to SCP and vice versa. This information allows a message to be distributed
throughout both networks. The instrument cluster is the only module on this vehicle that has this ability.