Select Monitor Adapter
Subaru Diagnostic Ports
How to build a PC adapter

Engine Control Unit (ECU)
Reading Error Codes
Reverse Engineering
ROM images

Transmission Control Unit (TCU)
Reading Error Codes
Reverse Engineering
Power Mode
ROM images

Other Control Units
Air Conditioning Unit
4WS Control Unit
Cruise Control Unit

OBD2 Information
Select Monitor Cartridge

Links to other sites

Custom TCU Development

Diagnostics and Datalogging Software

Select Monitor Software (Windows)
NEW 2023! Noriyasu Mori's superb Select Monitor Software is available in English and Japanese and can be downloaded from

VWRX Select Monitor Software (Windows)
Kevin Frank's Select Monitor Software can be downloaded from


Alcyone Software (Linux)
This is a collection of open-source software that I have written while working on this project. There are logging utilities for the ECU and TCU, and a program for downloading and manipulating ROM images. This is an updated version to fix problems experienced with recent Linux 2.6 versions. Download the latest copy here.


Evoscan (Windows)
Evoscan is a powerful and full-featured scantool, originally designed for Mitsubishi vehicles. The latest version works on Subaru vehicles including the SVX. This is definitely best software available at this time. See for more information.


Hex Com Tool (Windows)
The RS232 Hex Comm Tool from is very useful for troubleshooting your Select Monitor Adapter. It allows you to manually send hex command bytes to the ECU and view the response.


Rom Raider (Java)
Rom Raider, formerly known as Enginuity is an open-source tool that you can use to edit the tuning maps in the ECU. You can download it from

Polaris RXL Select Monitor (Windows)
This software is designed for use with Polaris Snowmobiles that use the Subaru Select Monitor Protocol. It can be used to download the ECU ROM to a file. Download it from

FreeSSM (Windows and Linux)
This software is an open source Select Monitor. OBD2 support is complete, ODB1 is under development. Download it from

JECScan (Windows)
This is a superb utility written by Tony Wilk. It can query ECU and TCU parameters, log to file, download ECU and TCU ROMs, read and write RAM and many other useful features. Full source code is included (visual C++). Download here.