E 250 V8-5.4L (2008)
ISO 9141 Communications Network
The ISO 9141 communications network is a single wire network. The ISO 9141 communications network does not permit intermodule
communication. The ISO 9141 is for diagnostic use only. When the scan tool communicates to the parking aid module (PAM), the scan tool must
request all information, the module cannot initiate communications.
The following module is on the ISO 9141 network:
-
PAM (if equipped)
The following fault chart describes the specific ISO 9141 network failures and their resulting symptom:
ISO 9141 Network Communication Fault Chart
MS-CAN
The MS-CAN uses an unshielded twisted pair cable of data (+) and data (-) circuits. The data (+) and the data (-) circuits are each regulated to
approximately 2.5 volts during neutral or rested network traffic. As bus messages are sent on the data (+) circuit, voltage is increased by
approximately 1.0 volt. Inversely, the data (-) circuit is reduced by approximately 1.0 volt when a bus message is sent. Multiple bus messages can be
sent over the network CAN circuits allowing multiple modules to communicate with each other and designed for general information transfer. The
MS-CAN will not communicate while certain faults are present, but will operate with diminished performance with other faults present. The MS-CAN
bus may remain operational when 1 of the 2 termination resistors are not present.
The MS-CAN operates at a maximum data transfer speed of 125 Kbps for bus messages and designed for general information transfer.
The following modules are on the MS-CAN:
-
Instrument cluster (IC)
-
Vehicle security module (VSM)
The following fault chart describes the specific MS-CAN failures and their resulting symptom:
