Can J1939 be enabled or disabled on a CM870

[Hamish]

I am trying to be proactive and save a backup of my ECM lest I should have trouble with my international 9900 cm870 which was demandated 12 years ago before I bought it (and still running fine). I can connect using Insite and it show J1939 multiplexing is disabled. Is this why I can only connect using J1708? Actually I can only connect through the dash 6 pin, and not the three pin on the engine, which seems odd to me. Saving a complete calibration using the appropriate software is estimated to take almost two hours, but always crashes around 30% in. Apparently the connection is too slow or unstable to be useful as is. Using 762 and 3.17 with inline 6 through usb on windows 7

[Rawze]

Are you using the 'Upload' option or are you trying to 'export' it?

The de-mandate file could also be corrupt, causing it to fail when copying it as well.

Do you know what your esn# is?.. and what program it is reporting it has in the ecm?.

Also, the most important thing to backup is the truck settings themselves. This can be done simply by making a work order, an ecm backup, and ecm template in Insite.

Just an FYI: On a CM870, copying the program out of the ecm to have it reviewed or to use it as a reference for certian settings is ok, but any backup of the ecm with Calterm on a CM780 cannot be re-used into another ecm, or copied back in without it corrupting the ecm. Newer engines (CM871 and newer) do not have this issue.

Last but certainly not least .. just because your truck has lasted for 12 years on a de-mandate file.. does not mean that file is decent at all. Even the worst de-mandates out there that are horrible for the engine all the way thru, there is always a few people here and there who get lucky, and their engine did not seem to fail prematurely. Put even the worst big-box horrible engine killing de-mandate programing into 100 engines, and 80% of them will fail with big problems prematurely, but about 20% of them will slip thru thru the cracks and 'seem' to run without as many issues due to the differences in how the truck is driven and a lot of other factors.

[Hamish]

The trouble I have is with the 'upload' option. Work order and template creation seem to work. The actual and reported ESN match, 79193393. Also the factory software version on the engine plate and reported from the created template match, AB10352.23. I do know that the ECM is not original, and was changed before I bought the truck.

Bummer that I can not 'upload' or copy back without corrupting the ecm as this was my plan for reverting back to the currently working setup quickly and easily. I may be able to purchase a used ECM with the same S/N and CPL. Could whatever improvements be made to a second ECM and keep the current ECM as a working spare that could be reinstalled in the field?

My goal is to become self sufficient with ECM related monitoring, troubleshooting and repair as I already am with all other repairs and maintenance. I have many spare parts and tools in the truck and have never needed to call a service truck. Big thanks for your overhead set and injector removal videos by the way.

In lieu of being able to compare an upload to the original calibration I would like to monitor the current setup for a while. Not sure if my connection speed will allow for that... I need to develop a sense of how much longevity has been consumed on the current rebuild (450,000 km on it now). At full power boost tops at 32psi and the pyro at 1000 DegF (not a very precise gauge). Oil seems to darken gradually over the 250 hr interval. Oil temp is about 230 DegF and may reach 250 DegF at full 565 hp for a half hour steady at 30 km/hr pulling a load up a mountain logging road in the summer. (still runs cooler than an average C15 of the same era.) By the way I hate lugging any ISX, so I think we are on the same page there.

[tree98]

Messing around with 870 ecm's is Playing with fire. They are notorious for Bricking while flashing in the file.

[Rawze]

(06-23-2022 )Hamish Wrote:  ...
Oil temp is about 230 DegF and may reach 250 DegF at full 565 hp for a half hour steady at 30 km/hr pulling a load up a mountain logging road in the summer.
...

That is a red flag for sure. Too much internal friction going on the create those high of oil temps. Should be cresting 230~ish max.. not 250+F.

As far as backing up the ecm.. that is fine .. sure you cannot put the file back into it but that is ok, it can still be referenced and reviewed. - What you need to restore the ecm is a clean factory file (known as an incal file) that has been done up properly (before putting it into the ecm) so that it can be flashed with whatever settings needed instead.

The CM870's in particular are the bas#tard child of the ISX world because of this flaw in the ecm. All newer model ISX's (CM871 and newer) do not have these issues with flashing them. They are also the only ecm where several ram memory settings have to be set even after they are flashed to get them right.