J1939 Communication Fault

[TGA]

Has anyone experienced a "J1939 Communication Fault"? We experienced a warning (light and shrill sound) after pulling into our site. There were no issues during the drive, but the warning sound continued even after we removed the key from the ignition. We started the RV again, put it in gear and put back in gear, etc. but the warning sound continued.

[ua40j]

A little more information is needed. What kind of RV, engine, chassis, transmission, year?

What light is showing? How did you get a J1939 error displayed? Do you have a Road Relay or some other kind of engine monitor?

J1939 is the data link protocol that allows the engine, transmission, and other electronic devices on your coach communicate. If you're getting this error, it's possible you have a disconnected cable somewhere around the engine control module, fuel pump, transmission controller, engine computer monitor, etc.

From what you said, it sounds like the engine still starts and runs.

Are the jacks down when you start your engine? ( I hate that noise)

[TGA]

We have a 2008 42ft. phaeton with diesel Cumings 360 HP, Spartan chassis, Allison transmission. The warning message and sound appeared after we pulled into our site after an 8 -9 hour drive. The sound continued even after shutting off the engine and removing the key. The levels were down. After almost an hour, the noise finally stopped. We called Spartan and the technician asked if we had driven through any rain during the day. He said that most likely that was the cause for the message and alarm and that is is nothing to worry about.

[ua40j]

His answer seems logical, but it also means you have a cable or connector that is exposed to water. You'll probably experience this again.

You might want to have someone crawl under the engine compartment and just take a look at your ECM connections and cables.

Hope you find the cause and don't have this happen anymore.