I'm working on an ECU from a car engine. When powering the ECU I get a J1939 NAME message. I was wondering do I have to do the same by sending an address claim with my nodes NAME or not?

The reason I'm asking this, the ECU won't send any other message via CANbus. I read on the internet that it should not be required if there are only 2 nodes and you know both addresses.

Other question I have, should an ECU send messages when the ignition is on or only when the engine is running?

EDIT: I tried sending the NAME of my nodes, but still the ECU won't send data on the CANbus.

  • Welcome to Motor Vehicle Maintenance & Repair! Are you sure the ECU you have is any good? Could be it's not sending you codes back because it's not functioning correctly. Nov 17, 2023 at 11:44
  • @Pᴀᴜʟsᴛᴇʀ2 Well the ECU is brand-new so I think that should not be the case. However if that's the case how can I confirm that the ECU is bad without opening it?
    – Smdeitz
    Nov 17, 2023 at 13:31
  • If the ECU is brand new, has it been programmed? Without programming, it won't be sending you any information, either. My suggestion is to get an ECU from the junkyard, or even use one on a vehicle so you can try what you're try to do to check functionality of your actions on a known good ECU which is programmed. Nov 17, 2023 at 13:38
  • @Pᴀᴜʟsᴛᴇʀ2. the ECU I'm dealing with isn't from a car. It's actually from a Kohler engine, one of their latest models. This engine relies on an ECU to manage its operations. I've gathered comprehensive information about the J1939 PGN messages it employs by reading the documentation I have. However, despite having this data, the ECU isn't currently transmitting messages over the CANbus.
    – Smdeitz
    Nov 17, 2023 at 14:46
  • Thanks for updating my understanding of what you're using. What you've stated sill leads me to believe the ECU you have may not be programmed. This can happen because the model of ECU may be used for different equipment, which would require a different program. They send them out blank so the end user can program then as needed. It is definitely something to consider. Nov 17, 2023 at 18:09


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