SD Card¶
Many rusEFI units have on-board microSD card slot. Most boards access SD cards via SPI. Technically some tiny percentage of SD cards do not support this any more, but it's really a tiny number. See this issue.
Validation Without Vehicle Power¶
- Windows 10 or Windows 11 is required, Windows 8 and older do not support the rusEFI Mass Storage Device.
- Ignition must be OFF or the ECU not even hooked to vehicle.
- Give it 15 seconds while connected only to PC via USB.
- A USB Drive is expected to apper. It culd be another letter like D:\ or F:\, but it should be in the list of drives.

- In TunerStudio, two green icons are expected:
