KWP2000 packet addresses...

Links to datasheets, websites, etc. relevant to the project

Moderator: Freon

Postby JonnyM » Sat Aug 12, 2006 4:33 am

MDTURBO wrote: as of right now everything I send out is getting echo'ed back to me. :/

No, it's not echoed.
You are using a single line for both transmission and reception, your transmitter and receiver are tied together.
Your receiver will therefore see everything you transmit, so you have to
do a dummy read for each byte you transmit in order to clear your receive data register.
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Postby MDTURBO » Mon Aug 14, 2006 8:07 am

arg, I read that thread and missed that info completely. I'll give that 360 baud trick a try.
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Postby MDTURBO » Fri Aug 18, 2006 12:27 pm

well still no luck.

I just ordered a ELM327 and will be spending my time programming for it. Let this stuff other stuff sit on the back burner.
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Postby Jon [in CT] » Fri Aug 18, 2006 2:28 pm

Ah, man! Don't give up! Have you taken a look at the Andy Whittaker software and hints at
Jon [in CT]
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Postby MDTURBO » Fri Aug 18, 2006 9:40 pm

Im having all kinds of issues. My tactrix cable is f-ed up, something inside it is loose and if it wiggles it gets disconnected. Do you all think that all the openEcu tools would work with the VAG-COM cable? Seems similar.
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Tactrix cable schematic

Postby ecudev » Sat Jul 14, 2007 11:59 am

Is this available somewhere?
Does it use both K and L lines? (i.e. pins 7 and 15) ?
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Postby wech » Tue Feb 19, 2008 1:18 am

you need both the k line and the l line. the l line is used only in initialization, during the communication it must be kept at high level
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Postby Justin 05 STi » Sat Nov 15, 2008 2:24 pm

I found some good KWP info here:

Everyone wants to know what the K-line interface looks like... well, it can take many shapes, depending on the complexity that you would like to add, but essentially it is a bidirectional communication bus (K-line) with an optional initialization line (L-line - optional, and if used, then only to output the 5 bps address byte). The interface described below, can be used for ISO:9141:1989, ISO:9141-2, KeyWord82, KeyWor1281, KeyWord2000 and other K-line protocols.

and here is some of the protocol to get you all going....

The Baud rates are generally between 1k and 10,4k bit/s. Common today are 4800, 9600 and 10400 (for most OBD-II equipped ECUs), however they could be any non-standard baudrate, with an interbyte time of approximately 10ms.
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