ECM....yes again!

[Diesel Freak]

I have been trying to read the messages

being transmitted out of the CANBus plug on a 2000 Dodge. I have a

prototype board consisting of a Microchip PIC, a MCP2510, and a PCA

82C251. I believe that I have set all of the parameters correctly

for the 2510, but when I set it to listen for all messages I receive

only one message repeatedly with an ID that is NOT defined in the

1939 standard (HS-1939). Is this port really using 1939? Has anyone

successfully received valid J1939 messages from this port? I only

want to read some basic parameters that should be broadcast

periodically from the ECM (throttle position, engine RPM, etc. ) so I

do not believe that I need to transmit to the bus (but I could be

wrong). Any help would be greatly appreciated.

 

[Shooter]

What did he say

 

[mongoose]

i understood the "2000 Dodge" part if that helps. :-laf

 

[Big-D]

No reason that shouldn't work... but then again I have '99. Oo.

 

[Batman]

Uh,,,,,,,,gee Beavis... ... ... ... ... . Uh, where's the hooch he's smokin?

 

[15w40]

Diesel Freak, I assume you are knowledgeable of the CANBUS protocols. You must send a Remote Data Request. By sending a REMOTE FRAME to a node requiring data and may request another node to send the corresponding DATA FRAME. The DATA FRAME and the corresponding REMOTE FRAME are named by the IDENTIFIER.



Several years ago I got a copy of the CANBUS specifications with the idea that I could reprogram the ECM. The problem is identifying the nodes used by Cummins and understanding their coding. That info is proprietary and is not found anywhere.

 

[Mark_Kendrick]

DF,

I think youre right. the bus should be live with data all the time.



If you're just listening you should be able to basically put a sniffer on the bus to monitor the traffic.



Try reaching Marco. He might be able to shed some light here.



I would bet you are hearing what you want to hear... all the parameter you are trying to watch have to be transmitted periodicallly they would appear to be a repeating pattern with very minor deviation.



You'd have to be missing something.



I'm glad to see you got this far. I know a lot about software but I wouldn't know where to start on hardware.



Gimme a yell maybe we'll both learn something.



Later,

Mark

 

[w-cummins]

Originally posted by Diesel Freak

I have been trying to read the messages

being transmitted out of the CANBus plug on a 2000 Dodge. I have a prototype board consisting of a Microchip PIC, a MCP2510, and a PCA 82C251.

Did you get this to talk to the bus? I"m looking to build a module that will sit on the CCD bus and respond to queries from the PCM directed to the ABS, and the AirBag controllers, that would respond with the "I'm Here/OK response" the PCM wants to see... . ( I removed them from the circuit on a conversion I'm installing) and I know that the PCM is going to throw codes every time it tries to poll them!

I believe that I have set all of the parameters correctly

for the 2510, but when I set it to listen for all messages I receive

only one message repeatedly with an ID that is NOT defined in the 1939 standard (HS-1939). Is this port really using 1939? Has anyone

successfully received valid J1939 messages from this port? I only

want to read some basic parameters that should be broadcast

periodically from the ECM (throttle position, engine RPM, etc. ) so I

do not believe that I need to transmit to the bus (but I could be

wrong). Any help would be greatly appreciated.

Do you by chance know the address's of the ABS and ABM modual's



Thanks



William.....