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Re: Accessing ECU Data via J1939

Did someone achieve to read data from the J1939 Can network (Engine Hours, Odometer) using a third party equipment?

New member

Re: Accessing ECU Data via J1939

[ Edited ]

I'm looking to add a thrid-party telemetry device to CAT excavating equipment.  These devices required J1939 - if the equipment has the J1939 pins (pins F & G), will I be able to read the engine messages (RPM, hours, oil temp, etc.)?  Is this information available on the bus or do I need to request messages?

Super Contributor

Re: Accessing ECU Data via J1939

There is no "list" that goes across the board, not public anyway. Also application plays large into what is allowed to get on the J1939. And increasing emissions regulation limits what manufacturers give access to. On some engines the primary J1939 allows no "outside" access at all, but some applications, like industrial engines, allow a large number of PGN's to be read and written to.

 

A good general reference is LEBH0005, this is an A&I Guide for Industrial engines that has probably one of the better descriptions of CAT J1939 networks and parameters.

 

Another resource that has VERY helpful tech support  and good inforamtion is Axiomatic,   http://www.axiomatic.com/

 

Hope that helps,

New member

Re: Accessing ECU Data via J1939

MikeL,

 

Thank you for the thorough reply, very helpful.

Is there a list of CAT "open" J1939 parameters? I also have all of the CAT service tools as well.


Thank you

Super Contributor

Re: Accessing ECU Data via J1939

Start by going to someplace like J1939.org and get familar with the protocol.

 

Next, you will need some form of a protocol convertor, something like this,

 

http://www.esd-electronics-usa.com/sae-j1939-starter-kit-with-USB-interface

 

Now you have to interface with the J1939 network, make sure you are wired per industry guidelines and that network termination resistors are in the proper place in the network, if you do something wrong here the whole thing comes to a stop.

 

Then you will need to know the PGN and SPN of the parameter you want to read, and how it is scaled to parse it into a number that means something.

 

Then it has to be a parameter CAT makes available to an "open" J1939 connection, not all data on the J1939 is readily available unless you have the proper access, like a CAT service tool.

 

Hope that helps, MikeL.

New member

Accessing ECU Data via J1939

Hello,

 

I am looking into ways to tap into the data (lets say just the engine hours) of a machine through the J1939 pins, without using the Comm Adapter.

I do not want to go down the Monico/premade systems side, I want to do this from scratch.
I am thinking of first tying into the cable, or using a CAT to J1939 adapter.

 

What would be my next step from there?

 

Thank you