Is there a protocol definition document for GM vehicles available of use in creating diagnostic VI's

[O_Proulx]

Hi Nike_.

The automotive diagnostic toolkit implements the KWP2000 protocol and UDS protocol.  This should help you use the OBD2 port of your car to get some data.

What data are you trying to acquire exactly?

[Nike_]

Dear All,

Please what I am trying to do?

Let You all know (forum participants) what is  my purpose and this maybe could help for better advices.

 A try for Building for a workshop car repair (small one car repair workshop) an electronic interface for enabling communication between Personal Computer and On Board Car Computer. ( a try for by-passing diagnostic equipments which   requires frequently updates for new car brands names, and are dedicated for only a small range of car brands  names)

1. As NI offers  software “NI Automotive Diagnostic Command Set” and hardware interface(s) for communicating with “inside car  network”, (of course communication based on the same spoken language between Personal Computer and Car On Board Computer) could be possible buy from NI necessary hardware and software for realizing this communication for Car(s)  Diagnostic Purposes (reading trouble codes, erasing errors, resetting program(s) into EPROM of Electronic Control Module of car(s), etc. or whatever command that  is included in the set, NI ADCS,   ) ( realizes this set this one?, or it server for a different purpose? )

( giving possibility to man who works on workshop for reading, and erasing, the car(s) electronic data available situation)

2. Does “NI Automotive Diagnostic Command Set” software and compatible NI _ hardware compatible with this software to have access into lately “Car(s) On Board Computer” for diagnostic purposes?

3. Is there possible to build this communication (Personal computer – car(s) On Board Computer )  for those purposes (repair purposes) with this “Set hardware and software” offered by NI?

4. To realize this communication for repair purposes there  “Must” be Information form car(s) manufactures?  

5. I am referring to the protocol that manufacturer(s) use to extract self diagnostic trouble codes from vehicles, there is the same (for most of the car(s) manufactured nowadays)  protocol that is used from mentioned NI command – set?

Best Rerds

Nike_

[Raj_V]

Nike_

I'm not sure if I understand you correctly but the basic idea of the automotive diagnostic command set is to be able to communicate with a car's ECU. I'm not sure if this is what you mean when you say "inside car network".

A list of functions supported by the command set can be found in the user manual at the link below.

http://www.ni.com/pdf/manuals/372139d.pdf

It can definitely be used for diagnostic purposes if you use compatible NI Hardware with the command set. I'm not sure if the protocol that manufacturers use is the same but as long as they use KWP2000 or UDS, then yes, it is the same protocol as the one in the NI Command Set.

[richardsonsf]

Hummer1,

What would I need to have access to low level CAN communications on GM vehicle?

Specifically, a 1999 Chevy 1500 work van.  I have many years experience with software development, from Macro accembler, to high level lanquages.

I would like to be able to see and filter CAN messages and log them.

If there is a document available to define say port numbers for Instrument Panel,

Body Control, module, ECM, etc, I would definitely like accress to that.

Sam Richardson

Wilmington, N.C.

[Frankay]

Hi richarsonsf,

Your message/question would be better suited for a new thread on this forum to increase the traffic and likelihood of getting responses from the community. I'm not sure how you might all of the CAN messages your ECU is sending/receiving, but this thread is describing using the Automotive Diagnostic Command Set to obtain the diagnostic signals from the car.

If you are looking for a community response to your question you should definitely create a new thread!

-----

Aaron F.

National Instruments