Flashing 04 STi ROM onto 04 F-XT ECU

[Porter]

Flashing an '04 STi ROM file (A2ZJ500J) onto an '04 F-XT ECU (A2ZJ500I) Has anyone done it? Is there even a way to do it?

The ECU hardware is essentially identical as far as I know. I'm in the process of a factory-perfect STi conversion and I'd like to avoid buying an ECU in the process if I can avoid it.

Any insight would be greatly appreciated!


Thanks,

Porter

[Freon]

Uncharted territory. I wouldn't recommend trying unless you can stand bricking the ECU.

[Porter]

Uncharted territory. I wouldn't recommend trying unless you can stand bricking the ECU.

Hmm... well, I guess I may be the first to try it!

If it works, that could be an interesting upgrade option for other F-XT folks who are running full STi conversions (including stock headers).

This is a few weeks out, still... hopefully someone else will chime in in the meantime if they know positively one way or the other.

[Freon]

Before you just go try, I would at least make sure they are pin compatible.

And remember, you brick it that could be all she wrote for that ECU. Paperweight.

[Porter]

Before you just go try, I would at least make sure they are pin compatible.

And remember, you brick it that could be all she wrote for that ECU. Paperweight.

They are pin compatible, 100%. Swapping it out is a common upgrade for the FXT folks.

Also, the engine is the same as an EJ257, down to every last part number.... with the exception of ONLY the turbo system (incl. intercooler), the exhaust manifold, and the fact that the intake manifold isn't powdercoated red.

I'm interested to see whether anyone else has ever tried this.

[twg]

pin compatible... but the map structure is way different. the STI has a lot more maps...

whether or not the actual hardware is the same, it might be better if you had someone with both the STI ECU and the FXT ecu open it up and compare...

i don't think anyone is willing to brick an ECU...

btw: can't you just copy the std STI maps over to the FXT ecu rom file and call it a day ?

[speedytang]

what is "brick" ?
Your uploading software to memory and should be able to convert it back without damaging micro circuits. I myself will try this next week and see if the car starts and do some driving logs. My/Our XT are really the same as the STI and have only found the exhaust , turbo, intercooler and bov being the only different parts. I don't see anything special since you can just swap the STI computer for ours. Sure will save $300 for another computer. I don't see anything being different but the fuel timing maps because of the STI weighing more and them having a 6 speed which both the above makes our XT faster with the same parts installed.

[twg]

Let us know how it goes.

I don't know why you'd risk it though when you can easily copy the appropriate maps over though with enginiuty...

[Freon]

"Brick" as into make your ECU into a brick by corrupting it so it can't be flashed and does not operate. Also see "paperweight."

If they are pin compatible, and they actually work just by swapping the whole unit, that bodes well for your chances. It doesn't necessarily mean all the pins on the CPU are used the exact same way, though it is certainly likely if the ECU part itself is pin compatible.

As suggested above, why not just copy the maps and/or effective tune? This would be far less risky. The other side of the coin with a pin compatible ECU is that once tuned with equal rigor, both should run just as well. Pin compatible and software compatible is also implying a lot about the power of the ECU being equal.

[speedytang]

I am trying to figure out why if you load a bad data set you just can't ground the clear pin on the memory chips to set them back to zero data points. I have been doing this for years on other makes so I just purchased another XT computer from the yard for $25 and will play around with it and see what all the mystery is about. I found the memory clear pin and erased the data clean or at least the scope said I did, but that will be verified tomorrow when I hook it up. I have a '04 STI map and will try to load it tomorrow. Nothing to lose but a lot for us XT guys to gain. While typing this I found the picture of a STI computer and to the eye everything looks the same as the 'XT computer but will blow up the pictures and get a better look.

[Freon]

I am trying to figure out why if you load a bad data set you just can't ground the clear pin on the memory chips to set them back to zero data points.

You can download the 7055 and 7058 microchip data sheets from the Renesas website for technical information.

The flash procedure Ecuflash uses requires existing microcode in the ROM before you start. If it is corrupted to the point where either the CPU faults and cannot run this existing microcode, you will be unable flash the ECU with Ecuflash. Ecuflash is triggering a branch in code in a preexisting "test mode" routine to that copies the boot loader from ROM to RAM, then programs the chip from code in RAM and data sent over the Tactrix cable.

There is a back door "boot mode" program method that can be used to flash it via a TTL line, but there is no existing hardware or software support to do this. Colby has some information posted about "shbootmode" on the main www.openecu.org wiki you can look at, but shbootmode is not actually in Ecuflash. I think he intended for it to be there and he'll get it back in some time, but for now it isn't supported.

[speedytang]

Now that makes sense
I need to figure out what software information is different between the XT and STI since the hardware seems to be the same. I am taking pictures tomorrow of the XT motherboard and load them into Auto-Cad and then find high-res pictures of a STI board and load it and find differences from overlaying the photos. The pin in and outs are the same and I really think the difference will be the fuel and spark tables and the max limits on RPM tables. The XT runs perfect with the STI computer. I will load the STI data this weekend and see what the XT computer does.
Question. What happens when people load STI tables to the WRX computer. A lot of differences between the 2.0 and the 2.5 just wondered what has happen or if the tune just fails since those computers would be totally different in design.

[Porter]

I'm running the STi tables (copied over) on my FXT, with the exception of the boost tables since I'm still running the TD04. Everything else powertrain is STi... headers, exhaust, intercooler etc. It runs great.

It's just the tables though, not the whole ROM file.