When you make configuration changes in the ECU Config area of V3 ECMLink and click Save to ECU or Copy to ECU, the settings are stored only in volatile memory until the ignition switch is turned off.

When the ECU sees the ignition switch turn off, but before power to the ECU shuts off, the ECMLink firmware transfers these settings to flash memory so that they can be reloaded the next time the ignition is turned on and the ECU powers up.

If your car is not retaining settings with V3, it's because the ECU is not shutting down normally by remaining on for 6 to 10 seconds before the MFI relay clicks off. The cause could be that the car's wiring was changed so that power for the ECU does not come from the stock MFI relay being controlled by the ECU, or battery voltage dropped low enough for the ECU to reset before the MFI relay shut off.

Later versions of the ECMLink ECU firmware are more tolerant of low battery voltage situations. v3.18.205 of the ECMLink ECU firmware introduced a check of battery voltage to avoid initiating a save of changed settings to the ECU unless the battery voltage is sufficiently high. In this case, the unsaved changes are lost without reverting everything to defaults.

Direct Access changes are not initially stored in volatile memory. They are stored to flash memory immediately upon clicking Save to ECU or Copy to ECU.