I’ve run into that before — Service Advisor sometimes doesn’t retain settings if the language pack or registry entries aren’t updated correctly. A couple of things you can try:
Run the program as Administrator, otherwise the config changes won’t save.
Go to the config.ini file or registry entries and check if the language really switches to “EN.” If not, edit it manually.
If the problem persists, reinstall and make sure the English language pack is selected during setup — some builds default back to Spanish if only one pack is active.
That usually fixes the issue and keeps it in English after restart.
By the way, I’ve been using John Deere Service Advisor 5.4 for a while now, and it’s been a huge step up compared to older versions. It works fully offline, supports both EDL adapters and Nexiq USB Link 3, and includes diagnostics, troubleshooting, calibrations, and full technical manuals. Basically the same tools Deere dealers use, but you can run it yourself without being tied to their service.
For anyone interested, you can check it out here:
John Deere Service Advisor 5.4 Agriculture