FAQ

Which cars and ECUs does FastECU support?

Subaru ECUs and TCUs from Denso, Hitachi, Mitsubishi and Unisia Jecs. The current list is under Supported models on the home page, and Vehicle & protocols explains how protocols are chosen. How much of each has been verified on a real ECU is stated on each connection page.

Is FastECU free?

There are two products. The original FastECU (Qt/C++) is open source and free. The newer desktop application that these pages describe needs a subscription for ECU access. Plans are not ready yet; see Account, plans & license key.

What can I do without a subscription?

Everything that works on files on your computer: opening ROMs, definitions, editing tables, the Hex editor, comparing ROMs and viewing saved datalogs. A license is needed for connecting to an ECU or TCU and for the AI assistant.

Do I need internet?

Only for the license check, updates and Remote control. A license that cannot be checked is tolerated for up to 7 days after the last successful check.

Which definition formats can I use?

RomRaider and EcuFlash XML definitions. See Definitions & loading ROMs. You can add your own as Custom definitions.

Where are my files?

FastECU keeps its calibration files, datalogs, system logs and Disassembler projects in folders you can change in Settings › Files. By default they are under the application data folder, %LOCALAPPDATA% on Windows and ~/.config on Linux.

Are my edits saved automatically?

No. Edits are made in memory. Use Save ROM As to write a file, and keep your original ROM untouched. Undo, the history and snapshots are described in Changes, history & tune files.

What if a write goes wrong?

That is why the documentation insists on a backup and on Test write. Read Reading & writing ROMs before your first write, and see Troubleshooting.

Can someone tune my car remotely?

Yes: see Remote control. You plug the adapter in and confirm each operation, and your tuner does the rest.

Can the AI assistant change my ROM or flash my car?

No. It can only propose changes that you approve, and ask to clear trouble codes with your approval. See What the assistant can do.

Does it work on Windows 7?

There is a separate Windows 7 / 8 build that has everything except the AI assistant and the Disassembler.

I cannot find the definition for my ROM

Try the ROM Database, and see Finding & defining tables.

Where do I ask questions?

On the support forum, or by email to info@fastecu.fi.