AutoXray EX-SCAN 5000, User Manual

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CAN is a high-speed data link that runs fifty times faster than the pro-
tocols currently implemented in today's vehicles. This speed, com-
bined with the new parameters defined for CAN, will give technicians
the ability to see data faster and gain a more accurate diagnosis.
In the past, protocols used by the car companies were proprietary.
This ended in 1996 with the advent of OBD-II, which forced the man-
ufacturers to select between 4 different types of communications:
J1850-PWM, J1850-VPW, ISO-9141 and ISO-14230. Allowing four
different protocols has created many complications in repair, inspec-
tion and maintenance.
CAN was first established by Bosch as an industrial control network,
but car companies soon found it was a very robust protocol for in-
vehicle use. As early as 1992, Mercedes and others placed intricate
CAN networks in their vehicles to handle communications between
controllers.
The CAN protocol has been integrated into the OBD-II spec by the
International Standards Organization (ISO) committee and has been
accepted as the standard diagnostic protocol by manufacturers. In
addition, the California Air Resources Board (CARB) has embraced
CAN and made it mandatory for all vehicles. Manufacturers can
begin implementing CAN in 2003 and must be CAN compliant by
2008 model year. The CAN standard is also a mandatory part of
each new state emissions inspection and maintenance program and
will be retrofitted into the established programs.
AutoXray's newest tool is CAN-ready and all AutoXray EZ-Link tools
are software upgradeable to support CAN.
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T
ECHNICAL
D
ESCRIPTION OF
OBD-I, OBD-II
AND
CAN