2004-2007 Subaru WRX
Link ECU G4X Subaru WRX PlugIn ECU — WRX107X (225-4000)
Upgrade your 2006–2007 Subaru WRX with the Link ECU G4X WRX107X PlugIn ECU. This advanced standalone engine-management system installs inside the factory ECU enclosure and connects to the original wiring loom, giving you complete control over fuel, ignition, boost, electronic throttle and advanced motorsport functions.
No complete standalone wiring harness is required for supported vehicles.
Important: Check Pins A1–A3 Before Ordering
Subaru used two different ECU configurations during these model years. The fastest and most reliable way to select the correct ECU is to inspect pins A1–A3 on your factory ECU connector:
- Wires installed in pins A1–A3: You need the Link ECU WRX104X
- Pins A1–A3 are empty: You need the WRX107X, part number 225-4000—this listing
Some late-production 2006 vehicles require the WRX107X. Do not order based on the model year alone.
Suitable Applications
- Subaru WRX V10 with EJ25 2.5L turbocharged engine
- Primarily 2007 models and certain late-production 2006 models
- GD and GG chassis with factory electronic throttle
- Manual-transmission vehicles only
Not Compatible With
- Vehicles with wires installed in connector positions A1–A3
- Automatic-transmission models
- GR, GH, GE or GV chassis
- Third-generation WRX models
Compare your factory ECU connector with the product photos and verify pins A1–A3 before purchasing.
FREE Link ECU USB Tuning Cable — $70 Value
Every WRX107X purchased from Kugan Tuning includes a compatible Link ECU USB tuning cable at no additional cost. Use it to connect your laptop for ECU configuration, diagnostics, data logging and professional tuning.
Why Choose the Link G4X WRX107X?
- Installs inside the factory OEM ECU enclosure
- Connects to the original engine wiring loom
- No complete standalone harness required
- Supports factory electronic throttle
- Advanced fuel, ignition, boost and camshaft control
- Launch control, anti-lag and flat-shift capability
- Expandable inputs and outputs
- CAN communication
- 512 MB of onboard data-logging memory
- FREE Link ECU USB tuning cable included—a $70 value
- FREE Kugan Tuning remote setup support included—a $297 value
Model Breakdown
- WRX104X: Primarily used in 2004–2006 vehicles with wires installed in pins A1–A3
- WRX107X: Primarily used in 2007 and certain late-production 2006 vehicles with pins A1–A3 empty
Connector inspection is the most reliable way to identify the correct ECU.
G4X Engine-Management Features
- Up to 6D fuel and ignition mapping
- Sequential fuel injection
- Precision closed-loop camshaft control
- Digital triggering with support for OEM trigger patterns
- OEM idle-control hardware support
- Electronic throttle control
- 5D boost control with three switchable tables
- Boost control based on gear, vehicle speed or throttle position
- Launch control
- Anti-lag
- Flat-shift control
- QuickTune automated fuel tuning
- Individual-cylinder correction
- Gear-based fuel, ignition and boost compensation
- Real-time selectable fuel, ignition and boost maps
- Continuous onboard barometric correction
- Staged injection
- Knock control with configurable knock windows
- Hall-effect, variable-reluctance and optical trigger-sensor support
- CAN communication
- Onboard statistics recording
- 512 MB of onboard data-logging memory
Expansion Connector Options
Expansion connections differ between the 2004–2006 and 2006–2007 ECU versions.
2004–2006 ECU Expansion Connector
- Analog voltage input 11
- Temperature input 4
- Analog voltage input 12
- Low-current 5V sensor supply
- Sensor ground
- Three unused positions
2006–2007 ECU Expansion Connector
The 2006–2007 V10 ECU includes an eight-pin expansion connector with:
- Auxiliary output 11
- Temperature input 4
- Auxiliary output 12
- Analog voltage input 11
- Auxiliary output 13
- Digital input 11
- Low-current 5V sensor supply
- Sensor ground
What’s Included
- Link ECU G4X WRX107X PlugIn ECU
- FREE Link ECU USB tuning cable—a $70 value
- FREE Kugan Tuning remote setup support—a $297 value
FREE Remote Setup Support — $297 Value
Purchase your Link ECU from Kugan Tuning and receive complimentary remote setup support to help prepare the vehicle and ECU for startup and professional tuning.
Remote setup support includes:
- Remote ECU connection assistance
- Basemap selection guidance
- Initial ECU configuration assistance
- Startup configuration review
- Sensor and input verification
- Guidance preparing the vehicle for professional tuning
This support helps identify configuration and sensor problems early, reducing unnecessary troubleshooting and wasted dyno time.
Custom remote tuning and dyno tuning are not included unless separately purchased. Successful startup and vehicle operation depend on correct installation, wiring, mechanical condition and ECU calibration.