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 related sites

Custom TCU Development

Diagnostics and Datalogging for Subaru SVX

NEW 2023! Noriyasu Mori has created a fanstastic new SSM software specifically for the SVX and other Subarus of that era.
He has also created an M37700 reverse-engineering tool (in Japanese) and done some analysis of the SVX ECU ROM.
Hitoshi Kashima originally reverse engineered the Select Monitor Protocol. He also designed the original Select Monitor Interface and ECU Memory Adapter circuits.
Andrew J Carr researched and designed a hardware monitor for the UK Impreza Turbo that connects to the Select Monitor port and allows monitoring and logging of the ECU data.
Vikash Ravi Goel has designed and built a Select Monitor interface, a "Juice-Box" based hardware monitor and open-source software for accessing Subaru Legacy ECU. See also Legacy Central for more info.
Kevin Frank has written a superb Select Monitor Utility for Windows that works on several Subaru models including the SVX (now that I have located the parameter addresses).
This site belongs to a Japanese owner who has undertaken a similar project on his 1995 Legacy. It hasn't been updated for a while. It looks like he wrote some windows software but it's no longer available to download.
David Wallis sells an ECU memory adapter board that allows the 27C1028 EPROM to be replaced by two 27C512 chips.
ECUtune is a company that specialises in ECU tuning for the Subaru SVX.
Calum Johnson is a specialist Nissan ECU tuner who has been extremely helpful with this project.
The SVX World Network is the SVX enthusiasts forum. Be sure to read the "Memory Dump of ECU" thread in the "Technical" section.
RomRaider is a site for Open Source ECU Tuning. It was formerly known as Enginuity.
ECU Explorer is open source software that works with a newer version of the Subaru Select Monitor Protocol. For cars produced after 1999.
Enduring Solutions produce a real time board for the JECS ECU. This allows maps to be changed in real time while the engine is running.
A select monitor program that runs on a PocketPC.
Evoscan software for Mitsubishi and Subaru vehicles. Works on the SVX.
Select Monitor Software for Polaris Snowmobiles (Their engines are built by FHI and their ECU uses Subaru Select Monitor Protocol). This utility can download the ECU ROM from Subaru cars.

.NET SSM This appears to be a code library and a number of logging utilities. It uses the later SSM protocol for cars produced after 1999. JDash is an ECU logging utility for ODB2 Subaru cars. Support for OBD1 is planned. Subaru Management And Research Tool. A new ECU reverse-engineering project from the guys at See this thread for more information. Nissan ECU Reverse Engineering site. Lots of useful resources and some of the smartest ECU hackers on the net. WinSSM datalogger that overlays parameters on a video feed. Very cool. Also some kind of hardware datalogger. FreeSSM. A very nice open source Select Monitor program. Windows and Linux versions. Currently only works with OBD2 but OBD1 is under development. EcuTek are the leading experts in reverse-engineering Subaru ECUs. They produce a range of tuning and diagnostic software specifically for professional tuners. Ready built cables, free datalogging software and performance chips for some vehicles. Ralph Watson, Special Engineer