Link G4X WRXLink (V3–V4) WRX4X ECU

The Link G4X WRXLink (V3–V4) WRX4X ECU is a direct-fit engine management system designed for early Subaru Impreza WRX platforms using the EJ20 engine. It installs into the factory ECU enclosure and connects directly to the OEM wiring loom with no modification required.

This ECU is intended for manual transmission vehicles only and provides full G4X tuning capability while retaining core factory functionality.

Important: Please confirm your ECU connector matches the header shown in the product images before purchase. An air temperature sensor is highly recommended. This ECU requires modification before electronic throttle can be used.

Engine Control Capability

• Designed for EJ20 turbo engines
• Sequential fuel injection
• Digital triggering using OEM patterns
• Precision closed loop cam control
• Staged injection support
• Knock control with windowing

Hardware and Platform

• Direct plug-in installation using factory ECU enclosure
• Continuous onboard barometric correction
• USB tuning connection
• CAN communication support
• 512 MB onboard data logging

Vehicle Compatibility

• Subaru Impreza WRX and STI EJ20 (1996–1998)
• GC8D and GC8E chassis
• Manual transmission only

G4X Plug-In Key Features

• Up to 6D fuel and ignition mapping
• OEM idle hardware supported
• 5D boost control with three switchable tables
• Launch control, anti lag, and flat shift
• Individual cylinder fuel and ignition correction
• Gear-based fuel, ignition, and boost compensation
• QuickTune automated fuel tuning
• Selectable dual fuel, ignition, and boost maps
• CAN communication support

I/O Expansion

Expansion Connector 1

• GND – Sensor ground
• +5V – Low current +5V supply
• DI5 – Digital input
• DI6 – Digital input
• Analogue Voltage 5 (0–5V)
• Analogue Voltage 6 (0–5V)
• Analogue Temperature 4
• Analogue Temperature 3

Expansion Connector 2

• GND – Sensor ground
• +5V – Low current +5V supply
• DI9 – Digital input
• DI10 – Digital input
• Analogue Voltage 8 (0–5V)
• Analogue Voltage 9 (0–5V)
• IGN7 – Auxiliary ignition output
• IGN8 – Auxiliary ignition output

Downloads and Resources

• Installation Manual (PDF)

View all Link ECU Resources