Backup and Recovery

Before you modify the CMU on a car you own, lease, or are authorized to service, set up a recovery path first. This page covers what to record beforehand and the recovery hierarchy — from the least disruptive option to a full factory reinstall.

Before You Modify Anything

Record your current state

Write these down (a phone photo is enough) so you know what “stock” looked like for your specific car:

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

The CMU must hold power throughout any update or modification. A power interruption mid-write can corrupt the filesystem and turn a routine change into a recovery job. Either:

Keep the engine running, or
Connect a battery tender if you’re working with the vehicle off.

Recovery Hierarchy

When something goes wrong, or you simply want to return to a clean state, work through these in order — least disruptive first.

There are two distinct mechanisms in this hierarchy. A revert (step 1) restores the exact files ScreenTune backed up before it modified them — it’s file-level, it’s our own tooling, and it needs the unit to still boot. A full firmware reflash (step 3) overwrites the whole root filesystem with an owner-obtained Mazda firmware image. They are not interchangeable.

1. Miatafy app — Uninstall (revert)

Best for: a supported ScreenTune install on the configuration it was validated against.

Open the Miatafy app and select Uninstall. This reverses supported ScreenTune changes in a single operation:

Removes all ScreenTune-installed tweaks and apps
Restores the backed-up configuration files to the state ScreenTune first captured
Returns the system to a clean state without a full firmware reflash
Keeps your current firmware version (it does not downgrade)

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

Best for: partial installs, a failed Uninstall, or an unusual system state.

If Uninstall doesn’t resolve the issue, or the install never completed cleanly, email support. Support can read the system state and tell you which step below applies before you reach for a full reinstall.

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 entire 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 — obtained through dealer/service channels, Mazda’s own update channels, your own prior backup, or otherwise lawfully obtained. We provide the procedure and tooling; the firmware binary itself is not ours to distribute. This is the same mechanism a dealer uses.

Requirements:

USB drive formatted FAT32, MBR partition scheme
4 GB minimum capacity
The correct-region firmware .up file for your unit, obtained as above — see firmware region codes
See USB drive requirements for formatting specifics

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

Best for: a hardware-level brick that never reaches the USB update path, or anything the steps above didn’t resolve.

If Uninstall 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

Symptom	Recommended recovery
Single tweak not working as expected	Miatafy app → Uninstall
Multiple issues after a recent install	Miatafy app → Uninstall
Uninstall 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

A firmware reinstall does not reset FORScan module changes — those live in separate ECUs, not the CMU filesystem.
A firmware reinstall updates the failsafe partition as part of its standard procedure.
A factory reset from the Settings menu is not the same as a firmware reinstall — see factory reset vs. firmware reinstall.
Always use region-correct firmware for a reflash.
A USB reflash only works while the unit’s auto-update path is intact. It is not unbrickable — a failsafe-level hardware fault needs SPI-flash service (step 4), not a USB drive.
Prepare a recovery path before you make any changes, not after.