2002-2005 Subaru WRXs require the use of an Initialization Connector when using an Accessport to flash a map on the ECU. The connector will be used during Install, Uninstall, and any full reflash of the ECU. This white connector is specific to the 2003-2005 WRX.
The 03-05 Subaru WRX requires the use of this particular Initialization ("init") Connector in order to get the car into Test Mode, which is when there is open communication with the ECU and a Reflash is possible.
Subaru 03-05 WRX Init Connector
Works on 2003-2005 WRX
Needed to Relash ECU
Test Mode Connector
*Pictures used for marketing purposes only, actual products may vary