The following steps outline the installation procedure for Subaru Plug-In ECUs:

1.Remove the factory ECU from the vehicle: Ensure the key is in the OFF position. The factory ECU is located under a steel cover on the passengers side floor (below the passengers feet). Lift the carpet, remove the cover panel. Unplug the wiring harness from the factory ECU. Remove the 6mm bolts (10mm socket) that retain the ECU and remove the ECU from the vehicle. DO NOT touch the exposed pins in the factory ECU connector.

2.Remove the factory ECUs circuit board from its enclosure: Ensure you are following the given anti-static guidelines and ARE WEARING A CONDUCTIVE WRIST STRAP connected to a conductive working surface. Remove the top and cover from the ECU enclosure by removing the side retaining screws. Remove the circuit board by removing the retaining screws. Hold it only by the plastic header and place it aside.

3.Fit the Link Plug-In ECU: Remove the ECU from its packaging and place it immediately in the factory enclosure. Place the factory ECU in the packaging your Link ECU came in for its protection.

Note: The G4X WRXLink (04) Plug-in ECU can fit two case sizes. If the ECU PCB is too large for the case, carefully snap the PCB extensions off at the lines shown in the image below.

 

4.If the ECUs USB tuning cable is to be left permanently connected, a slot will need to be cut in the top cover. The best place to do this is usually beside the factory header.

5.Reassemble the enclosure and fit the ECU back to the vehicle.

6.Connect the ECU to the factory wiring loom.

7.Do NOT attempt to start the vehicle. Proceed to read through the remaining sections of this manual first.