OBD2 Information

SVXes sold in the USA from 1996 onwards were fitted with a different type of ECU and TCU in order to support the OBD2 standard. Late model SVXes are rare and we have not had much opportunity to research these units. The hardware is the same as that used in some Impreza and Legacy models of the same year.

There are plenty of OBD2 compliant scantools available which should work on the OBD2 SVX. There is also a fair amount of information available on the internet about communicating with and modifying OBD2 Imprezas. Much of that information will probably apply to the SVX. It just needs somebody with an OBD2 SVX and computer/electronics skills to investigate it. If anybody undertakes such a project then I would be interested to hear about it.

Tim Smith recently sent me a memory dump of his 1998 impreza that uses this type of ECU. From looking at the file, it appears that the CPU is related to the M377xx family used by the older OBD1 cars. I think it has 60K of ROM (address 0x1000 to 0xFFFF) and 4K of RAM (address 0x0000 to 0x1000). Please do not regard this information as definitive because I have not yet studied it extensively.

Thanks to John Spiro-Colwell for sending me the pinout for this ECU. OBD2 ECU Pinout.