Building a J1939 engine-ECU replacement for an electric conversion — anyone done this?

[galstaf]

I’m looking at converting an industrial telehandler (forklift) to a full electric drive after the Tier-4 diesel seized. The forklift controller expects a J1939 diesel engine ECU on the network, so without one it derates or disables functions.

I’m looking for advice from anyone who has:

built a custom J1939 node

emulated an engine ECU

or integrated EV drive systems with industrial CAN/J1939 controllers

Goal: create a “replacement ECU” that publishes engine-related PGNs and responds to torque/speed requests so the machine controller continues to operate normally.

Has anyone here tried something like this, or can point me toward recommended hardware, software stacks, or example projects?

Thanks all!

[galstaf]

More details for anyone interested:
Machine: forklift with Cummins Tier-4 originally
New powertrain: electric motor and as much hardware as possible from crashed EV with non OEM inverter (preferably OpenInverter:)
)
Need to emulate:

• PGN 61444 (engine speed/torque)
  
  PGN 65262 (coolant temp)
  
  PGN 65263 (oil pressure)
  
  address claim, ACK behavior, correct timing, etc.

Looking for experience with:

• low-cost J1939 node hardware (Teensy 4, STM32, ESP32+SN65HVD230)
  
  open-source J1939 stacks (maybe? TruckHacking J1939: https://github.com/TruckHacking/j1939)
  
  CAN sniffing tools (SavvyCAN: https://github.com/collin80/SavvyCAN)
  
  PCAN-USB (https://www.peak-system.com/PCAN-USB.199.0.html)
  
  GVRET firmware for CAN reverse engineering (https://github.com/collin80/gvret)

Primary tasks:

• Publish the expected engine PGNs at proper frequencies
  
  Parse machine controller’s torque request messages
  
  Drive inverter based on torque requests
  
  Provide correct ACK and error-frame behavior so the machine doesn’t derate or lock out

If anyone has worked on:

• J1939 ECU replacement
  
  EV swaps on industrial machinery
  
  CAN spoofing for non-emissions reasons

I’d appreciate guidance or examples.

Thanks again.