Link G4X MR2Link V1 TST185X ECU

The Link G4X MR2Link V1 TST185X ECU is a direct-fit engine management system designed for early Toyota turbocharged 3S-GTE platforms. It installs into the factory ECU enclosure and connects directly to the OEM wiring loom on supported vehicles.

This ECU is intended for manual transmission vehicles only and supports most factory systems while providing advanced tuning capability through the G4X platform.

Important: Manual transmission only. Designed for 3S-GTE engines. A Link intake air temperature (IAT) sensor is highly recommended. E-throttle requires modification before use. Please confirm your ECU connector matches the header shown in the product images before purchase.

Engine Control Capability

• Designed for early 3S-GTE 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

• Toyota MR2 SW20 (1989–1992)
• Toyota Celica ST185
• Manual transmission only

Exclusions: Not compatible with Celica GT-Four RC or Carlos Sainz Special Edition models. These require the MR2Link V3 TST205X Plug-In ECU.

G4X Plug-In Key Features

• Up to 6D fuel and ignition mapping
• Sequential fuel delivery
• OEM idle control 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

The following expansion connector inputs and outputs are provided:

• GND – Sensor ground
• +5V Out – Low current +5V supply
• DI5 – Digital input
• DI6 – Digital input
• DI4 – Digital input
• Analogue Voltage 4 (0–5V)
• Analogue Voltage 5 (0–5V)
• Analogue Voltage 6 (0–5V)

Ignition expansion: An optional ignition expansion module allows conversion to direct spark ignition or use as auxiliary outputs. This module is not included and must be purchased separately.

Ignition Expansion Pinout

• Ignition 1
• Ignition 2
• Ignition 4
• Ignition 3

Downloads and Resources

• Installation Manual (PDF)

View all Link ECU Resources