1989-1992 Toyota MR2 Link Ecu G4X
Link ECU G4X Toyota MR2 & Celica 3S-GTE PlugIn ECU — TST185X
Upgrade your Toyota MR2 or Celica GT-Four with the Link ECU G4X TST185X 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 and advanced motorsport functions.
Designed for compatible early Toyota 3S-GTE applications, the TST185X delivers modern engine-management capabilities without requiring a complete standalone wiring harness.
FREE Link ECU USB Tuning Cable — $70 Value
Every TST185X purchased from Kugan Tuning includes a compatible Link ECU USB tuning cable at no additional cost. Connect your laptop directly to the ECU for configuration, diagnostics, data logging and professional tuning.
Why Choose the Link G4X TST185X?
- Designed for compatible Toyota 3S-GTE applications
- Installs inside the factory OEM ECU enclosure
- Connects to the original engine wiring loom
- No complete standalone wiring harness required
- Advanced fuel, ignition and boost control
- Launch control, anti-lag and flat-shift capability
- Expandable inputs and outputs
- Optional direct-spark ignition expansion
- 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
Suitable Applications
- 1989–1992 Toyota MR2 SW20 with a compatible 3S-GTE engine
- Toyota Celica ST185 GT-Four
Important Model Exclusion
The TST185X is not compatible with the following ST185 special-edition models:
- Toyota Celica GT-Four RC
- Toyota Celica Carlos Sainz Special Edition
- Toyota Celica Group A Rallye
These vehicles require the Link ECU TST205X PlugIn ECU.
Important Compatibility Information
- Compatible with manual-transmission vehicles only
- Compare your factory ECU connector and pinout with the product photos before ordering
- Compatibility depends on the factory ECU connector and pinout—not only the vehicle’s model year or engine
- A Link ECU intake-air-temperature sensor is highly recommended
- Electronic-throttle operation requires an ECU modification before it can be used
- Most factory vehicle functions are supported, but availability can vary by model and configuration
- Engine-swapped vehicles may require additional wiring, sensors and configuration
- Professional installation and calibration are strongly recommended
G4X Engine-Management Features
- Up to 6D fuel and ignition mapping
- Sequential fuel injection
- Precision closed-loop camshaft control where applicable
- Digital triggering with support for OEM trigger patterns
- OEM idle-control hardware support
- 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
I/O Expansion Options
The expansion connector provides the following inputs and outputs:
- Sensor ground
- Low-current 5V sensor supply
- Digital input 5
- Digital input 6
- Digital input 4
- Analog voltage input 4
- Analog voltage input 5
- Analog voltage input 6
Optional Ignition Expansion
An optional ignition-expansion connector allows the engine to be converted to a direct-spark ignition system. These outputs may also be configured to control compatible auxiliary devices.
The ignition-expansion pinout is:
- Pin 1: Ignition output 1
- Pin 2: Ignition output 2
- Pin 3: Ignition output 4
- Pin 4: Ignition output 3
The ignition-expansion cable is not included and must be purchased separately.
What’s Included
- Link ECU G4X Toyota TST185X PlugIn ECU
- FREE Link ECU USB tuning cable—a $70 value
- FREE Kugan Tuning remote setup support—a $297 value
The optional ignition-expansion cable and intake-air-temperature sensor are not included unless selected separately.
FREE Remote Setup Support — $297 Value
Purchase your Link ECU from Kugan Tuning and receive complimentary remote setup support to help prepare the ECU and vehicle for startup and professional tuning.
Remote setup support includes:
- Remote ECU connection and setup 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 compatibility, installation, wiring, mechanical condition and ECU calibration.