Unless I'm extremely confused, your solution uses both GM and subaru ECUs correct?

Or are you removing the subaru ECU?

I'm not a vendor here so I can't talk much about the project itself. By the end of it, the car won't know it doesn't have a FA20. :)

I want one so hurry up!

In order to keep the factory ecu in place you would have to send it specific signals to make it do its job. It would be much easier to just put the info onto the can bus via one of there products and have the gm ecu send data to it.

Really hoping you guys get everything worked out by the time I'm ready for and ls swap. if you need a car guinea pig vehicle let me know, My BRZ isn't my daily, i can afford to part with it for a while ;)

Not if you intercept and modify all the messages the ECU broadcasts on the network and supplant it with the values you want from GM :thumbup:

I still feel leaving a factory ecu in place (fa20), when you are able to output what you want through your own box (one of the mrs electronics products) is a waist of time. As well its (the fa20 ecu) broadcast output is limited with zero engine speed. Why work around that when you can ditch the factory ecu and just use a gm. The gm can output the majority of the info the system (factory can bus) is looking for, just have your own box recode it for the chassis to be happy. I will just stick with an ems system for total control.

Why remove one of the most central modules in the vehicle's system when all we need to do is supplant the data coming out of the module with all of the data from GM? This works on three different platforms so far.

It's not working around, its working with. Eventually if I learn the entirety of the network traffic from the ECU and what it means. People know this, I don't. I just haven't spent the time to RE the whole message structure from the ECU, I just know what I need to know for the rest of the car to not complain. This would bring the packaging of the solution down to a module the size of a larger automotive relay...

Cause when the ecu does not see the engine running the info that is output is minimal. For the amount of supplemental data it is only a little more to just replace the ecu. Good luck with your project.

You must live in one of the dozen or so states that doesn't require the obd2 emissions readiness test annually for an inspection sticker. Must be nice. For the rest of the country though. Keeping the factory ecu happy is a monumental step forward in keeping your LS swap road legal.

If it's a race car? Absolutely. Who cares. Replace the ecu. But keeping the stock ecu functioning somewhat. Is essential for the obd readiness test.

CAN messages are broadcast regardless of engine status as long as the ECU is powered on, next.

EDIT: Also, for immobilizer push button start cars it could be an issue to remove the OE ECU.

^This. We've had more requests for emissions compatible swaps and it is becoming a big issue in the aftermarket. A standalone will probably never implement catalyst controls or be able to certify their controllers as emissions ready. Using the OEM ECU/PCM is the solution for those who need emissions.

Unless you know someone who wants to disassemble every possible OS and reprogram the GM PCM to spit out the appropriate messages and data, this is the way.

Back of the line bud! :D.......once again I'm the guniea pig working with MRS Electronics and have been pushing Collin to share on this forum, dont think he likes too, but I know some of you are on the cusp of doing the swap and need the info......Can-bus and related is what this man and this company do for a living and in most cases on a much larger and complex scale, just check out their web site.....if anybody can figure this crap out they can.......we are in good hands for a simple cost effective solution, its just going to take a little research and ground work, a product I'm sure will be available soon.

@MRS-Colin can I just run the OEM GM ECU and your product for my swap or do I have to keep the FR-S ECU as well. I need to know so I know if I can sell the FR-S ECU. If you need a ECU from a FR-S to work with to help you develop your product further let me know where to ship it. The car is down and will be until March.

Contact me through other channels and we can talk.