Backup and Recovery
Before modifying the CMU, record its current state and know which recovery path applies.
Before you modify anything
Section titled “Before you modify anything”Record your current state
Section titled “Record your current state”Record these items with a phone photo:
- Firmware version, region, and failsafe version, from Settings → System → About
- Which apps appear in the Applications menu
- Whether CarPlay / Android Auto is currently working
Ensure stable power
Section titled “Ensure stable power”The CMU must hold power throughout an update. Either:
- Keep the engine running, or
- Connect a battery tender if you’re working with the vehicle off.
Recovery hierarchy
Section titled “Recovery hierarchy”When something goes wrong, or you simply want to return to a clean state, work through these in order, least disruptive first.
A revert restores ScreenTune’s first-install backups and requires the unit to boot. A full firmware reflash overwrites the root filesystem with an owner-obtained Mazda firmware image.
1. ScreenTune USB: REMOVE
Section titled “1. ScreenTune USB: REMOVE”Best for: a supported ScreenTune install on the configuration it was validated against.
Insert the matching ScreenTune USB and select REMOVE. This removes active ScreenTune files, restores the first-install backups, and leaves the firmware version unchanged.
A revert returns the unit to what ScreenTune first captured, not guaranteed factory-stock. If the car was already modified before our first install, that prior-modified state is the baseline restored. Only a true firmware reflash (step 3) guarantees factory.
2. Support-assisted recovery
Section titled “2. Support-assisted recovery”Best for: partial installs, a failed REMOVE action, or an unusual system state.
If REMOVE does not resolve the issue, or the install never completed cleanly, email support. Include the screentune.log file from the USB so support can identify which step applies before you reach for a full reinstall.
3. Full firmware reflash (USB)
Section titled “3. Full firmware reflash (USB)”Best for: unknown prior modifications, a missing backup, dealer prep, a unit that won’t boot, or establishing a known-clean factory baseline.
A full reflash writes a correct-region Mazda firmware .up package over the operating system:
- Overwrites the entire root filesystem and returns the unit to factory state
- Removes all modifications (ScreenTune, legacy AIO, manual edits)
- Clears Bluetooth pairings and audio presets
- Updates the failsafe partition
- Takes 20–40 minutes
Miatafy does not ship the firmware. You supply the .up image through dealer or Mazda update channels, your own backup, or another lawful source. See firmware recovery for requirements and procedure.
A reflash needs the unit’s USB auto-update path still intact. It is not universal: a boot- or failsafe-level hardware brick can leave the unit unable to read the USB drive at all, which no firmware file fixes. After a successful reflash the CMU boots in factory state. CarPlay still works if the USB hub hardware is present.
4. Mail-in / in-person recovery service
Section titled “4. Mail-in / in-person recovery service”Best for: a hardware-level brick that never reaches the USB update path, or anything the steps above didn’t resolve.
If REMOVE and a USB reflash both came up short (or the unit won’t read a USB drive at all), the failure is below the USB update layer. For that case, recovery is available as a paid mail-in or in-person service: a repair act at the SPI-flash level, which no USB drive can perform. Email support rather than guessing which path applies.
Recovery decision tree
Section titled “Recovery decision tree”| Symptom | Recommended recovery |
|---|---|
| Single ScreenTune change not working as expected | ScreenTune USB → REMOVE |
| Multiple issues after a recent install | ScreenTune USB → REMOVE |
| REMOVE did not resolve the issue | Contact support for assisted recovery |
| Unknown modification history (used car, previous owner) | Full firmware reflash (USB) |
| Preparing for a dealer visit | Full firmware reflash (USB) |
| Boot loop (unit restarts repeatedly) | Wait for failsafe, then full firmware reflash (USB) |
| Unit won’t read the USB drive at all (hardware brick) | Mail-in / in-person recovery service |
| Want to return completely to factory stock | Full firmware reflash (USB) |
Important notes
Section titled “Important notes”- A firmware reinstall does not reset FORScan changes because they live in other control modules.
- A factory reset is not a firmware reinstall; see factory reset vs. firmware reinstall.
- A reflash requires region-correct firmware and a working USB update path.