Just in case anyone is looking at creating an OBDII/CAN diagnostic system for the Z, one of the challenges has always been getting a OBD plug at a reasonable price.

JAYCAR now have this plug as a stock item P/N PP0720 at $30.00

No hood is supplied but the bits you need are there. ELM Electronics ( Canada ) sell a PIC microcontroller that handles all the interface tasks to a PC serial port. ( make sure you buy the right standard as there are a number of options.....

If anyone gets motivated to build - drop a line, I can help.

 

I have been Hunting for a while now and cannot find anyone that makes a kit or info on reading OBDII codes from a CAN fitted car. If you have info please shoot me a PM.

Heaps of info out there for non CAN fitted cars though.

 

OBDII and CAN are different animals - although on the Z they share the same plug ( as is permitted in the OBD spec ).
OBDII is a standard emission diagnostic system that has very definate uses and limits in its publically defined version. There are manufacturer extensions to OBDII but once again they do not have to be publically listed like basic OBDII.

CAN is the actual bus system that the Z uses to communicate between all the electronic subsystems.

OBDII only responds when asked ( although its monitor programs run more or less continuously ) whereas CAN has a high speed continuous data stream. The problem here is that whilst OBDII ( core )is fully specified in hardware and software, CAN is not. The CAN hardware and communication protocols are tied down, but the meaning of the data is not. A CAN code on one system could and usually is completely different from the next - whereas OBD is always OBD. The job of analysing the CAN bus is basically one of reverse engineering, information is just NOT availalbe easily.

So even if you tap the CAN bus - and there is hardware out there ranging from moderately priced to #$%^& that can do it, working out what the data means is another story.

I am working on this "challenge" through some contacts but its not going to be an easy or quick task. OBDII is easy and could help with tuning ( the data is limited but sometimes usefull ) but as for actual "deep" diagnostics its use is limited.

Lets keep at it - its a CHALLENGE but the rewards for working it out are great.

 

WHAT THE?????!!!!!

I have NO idea what all this means but sounds interesting.

Hey REDZED, I'm tryin' to keep up but .... well, is there an easy explaination like for a 6 year old?

 

I will try and source some information in "English" for you, but in summary....

OBDII is On Board Diagnostics Ver 2, its a US standard that applies to all modern cars and gives fundamental information in a standard format from a standard plug about the engine and emission system. Commonly doccumented, easy to interface with, but quite limited.

CAN is Controller Area Network and is the computer "network" used in the Z ( and many other cars ) that allows data to be communicated between all the black boxes. There is heaps of information available but it is not doccumented. A VERY powerfull source of information on just about every box but very hard to track down. If you have the capability to decode all the CAN data you can monitor just about everything electronic.

CAN runs the cars electronics OBDII is a simple diagnostic.

Hope this clears things up a little......

 

Whew!!! My brain hurts......

I'm just glad there are smart people in the world who know this stuff so I don't have to. I'm still tryin' though.

Thanks for the explaination REDZED.