Would make life a whole lot simpler if all markets used the same
propocol - if what you say is true Subaru has to make a minimum of 3
different versions of every computer - and possibly different
harnesses as well?
All 3 standards are implemented in almost identical methodology,
using the same SAE J1962 pinout and connector. Only the actual
"regulation" has any appreciable difference. Within the OBD2 standard
there are 5 different "protocols" used.
Each protocol uyses a different pulse train - with different
frequencies and coding.
SAE J1850 PWM (pulse-width modulation - 41.6 kbit/s,) is the standard
of the Ford Motor Company.
SAE J1850 VPW (variable pulse width 10.4 kbit/s) is the standard of
ISO 9141-2 .(This protocol has an asynchronous serial data rate of
10.4 kbit/s. It is somewhat similar to RS-232; however, the signal
levels are different, and communications happens on a single,
bidirectional line without additional handshake signals.)
ISO 9141-2 is primarily used in Chrysler, European, and Asian
ISO 14230 KWP2000 (Keyword Protocol 2000)
I'm not sure how this one works or who, if anybody, currently
ISO 15765 CAN (250 kbit/s or 500 kbit/s). The CAN protocol was
developed by Bosch for automotive and industrial controllers. Unlike
other OBD protocols, variants are widely used outside of the
automotive industry. While it did not meet the OBD-II requirements for
U.S. vehicles prior to 2003, as of 2008 all vehicles sold in the US
are required to implement CAN as one of their signaling protocols. It
is used in conjunction with one or the other of the standard prorocols
on most current vehicles.
Your scanner can tell which protocol to use by a combination of which
pins are used and the frequency and/or voltage on the pins..
On top of the mandated OBD2 standard, many manufacturers supply a lot
of other data from other systems on the car through the OBD port using
a "standard" or "protocol" called EOBD2 - which is not "European" but
Some EOBD2 codes can be read by some basic OBD2 scanners, with
better/later scanners also able to read CAN bus codes , and the higher
end units capable of reading the EOBD2 codes of MOST manufacturers. No
manufacturer is "required" to make their codes available on generic
code readers and some may choose to require specific diagnostic
equipment to access these codes.
My only suggestions involves where I would start my research. I'd
probably try to email the guys at www.troublecodes.net with my
question. Hoping that they knew of a way to force a 'blink code' or
maybe one of their 'link partners' that deal with reading systems
other than OBDII.
I would also post the question at NASIOC and at www.ultimatesubaru.org
Maybe the Australians get the same vehicles you are getting? Search
for folks building sandrails - some Aussies build them with soob
yeah, definitely try contacting some folks at these links;
On Mon, 05 Jul 2010 23:36:19 +0600, Yousuf Khan wrote:
Turmoil? Nah, no turmoil. We just have so little to discuss about Toyotas
that we tend to "wander" a little! ;)
As far as OBDII, I thought the port was universal. My '95 Tercel had one,
although it was required until 1997.
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