Guide / Flash Unlock
Flash Unlock
The Flash Unlock prepares the ECU for flashing through simos.app.
Allow at least 30 minutes for the complete process, including the unlock and the first file flash.
Contents
Before You Start
Connect a battery charger
A stable battery voltage is important during the unlock and flashing process.
If the voltage becomes too low, the ECU may interrupt communication and the process can fail. Connect a suitable battery charger before starting whenever possible.
Install the correct dongle firmware
Your dongle must be running the current simos.app firmware.
This is especially important if the dongle was previously used with SimosTools.
Install the firmware here: simos.app/dongle/firmware
Prepare a matching ECU file
You must have a compatible stock or tuned file ready before starting.
After the Flash Unlock, the ECU may not contain a runnable software state. The vehicle will not start until a valid file has been flashed.
Use the ECU information shown for your vehicle in simos.app to select the correct file:
• ECU boxcode
• Boxcode version
• Boxcode version
The file must match both values.
Starting the Flash Unlock
1. Connect a battery charger.
2. Plug the dongle into the vehicle.
3. Switch the ignition on.
4. Keep the engine off.
5. Connect to the dongle using the simos.app application.
6. Select Flash Unlock.
7. Start the process.
2. Plug the dongle into the vehicle.
3. Switch the ignition on.
4. Keep the engine off.
5. Connect to the dongle using the simos.app application.
6. Select Flash Unlock.
7. Start the process.
No further input should normally be required during the unlock.
Do not unplug the dongle or switch off the ignition unless the application instructs you to do so.
If the Unlock Is Interrupted
The Flash Unlock can be restarted from the beginning.
If the ECU no longer contains runnable software, simos.app may not be able to detect the ECU type automatically. In this case, manually select the correct platform:
SCG — Simos 18.10
SC8 — Simos 18.1 / 18.6
Then start the unlock again.
If the Unlock Cannot Be Completed
The Flash Unlock can normally be restarted from the beginning at any time.
If the ECU no longer contains runnable software, simos.app may not be able to detect the ECU type automatically. In this case, manually select the correct platform:
SCG — Simos 18.10
SC8 — Simos 18.1 / 18.6
If the unlock cannot be completed for any reason, you can always use Flash Stock to write the matching original stock BIN. This restores a runnable stock software state and re-locks the ECU.
Make sure the stock file matches the ECU boxcode and version shown for the vehicle in simos.app.
After the Unlock
After the Flash Unlock has completed, immediately flash the matching stock or tuned file.
The vehicle will not start until a valid software file has been written to the ECU.