It sounds like your interface required for FW download is also not present, based on that Secondary error code: 5. To simplify the update process, you can force the device to stay in Bootloader upon reset by flipping the dip switch SW401, position 7, to the ON position. That switch is tied to the Service Pin (SVC_PIN) on WP. When you power cycle or reset in that configuration, the console should include a message like:
B - 2516067 - SVC PIN detected
And the console logs should stop before loading the kernel. In Windows you should see a DM Port serial interface, (from the CF3 USB interface, not the console), and the Windows One-click tool should now be able to use that for the update.
Note that the switch means it will always boot to Bootloader, so you need to flip it back either after the download starts, or after the download is complete, to boot the system back up and validate the download. The switch isn’t polled or tied to an interrupt, so if you toggle it after the download is complete, you’ll need to power cycle to reboot into normal operating mode. If you switch it during the download, the reboot cycle following the flash procedure will sense the change and automatically boot to normal operating mode. Just be careful not to power cycle during the download.
Hope that helps. Once you have updated from Release 4/4.1 to Release 8 I think your ECM problem should be resolved too.