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I managed to get my hands on this chipped ECU from Blitz (yes, I have a JDM S5 Turbo like what it's meant for). I can assume it changes the fuel map, makes timing more aggressive, and eliminates fuel cut. Does anyone else have any other information on it? I've so far only found one post. It's from 2001 and doesn't even have a *picture* of the ECU, let alone much info. Anything helps
Might be worth cracking it open, taking some pictures and copying the rom. I've got some pictures somewhere of the inside of an rtek, but I'd be curious to see how hard it would be to recreate these mods
Might be worth cracking it open, taking some pictures and copying the rom. I've got some pictures somewhere of the inside of an rtek, but I'd be curious to see how hard it would be to recreate these mods
Appears to be a Hitachi HN27C256GJ-20 chip they've reprogrammed and soldered in. I can't see if there's any more info on top of the chip itself, because the "sticker" they put on it appears to actually be a tiny metal plate that's glued on. At least it feels like it, and I can't peel up the corner to pull it off. I have a picture of the inside of my regular stock JDM S5 ECU I have, but it's slightly too blurry to see what's written on the chip it replaces. It does not appear to just be a different version of the same chip. Not 100% sure though
you probably ran into most of this already, but the stock Mazda chip is not reprogrammable. so to change the ECU program you need to change the chip. the new chip is probably flashable.
the JDM tuners also had the ECU fully cracked, so the program on the chip could be almost anything.
usually they do a basic tune, which is remove the limiters (boost, speed and rpm), and then redo the fuel map for whatever they thing a typical boost up setting is
but, since its fully tunable, they could have built a car, and dyno turned that, and that ECU would be specific
comparing the BIN file to like an R-Tek or another ECU would be interesting to do. also a lot of these shops can still do these things. i don't know about Blitz, but Knighsports will reflash their ECU's still
Don't peel off that sticker! It blocks the UV window on the rom chip. Old rom chips that were rewritable had a window so you could wipe the chip using UV light. You must leave the sticker on or you could wipe the rom off the chip. The important ID numbers are visible, 27c256. It is a 256 kilobit rom chip, same as the N370 TII ecu for the US. As far as what the rom is, it would have to be desoldered and read to a pc.
Thanks for the pictures. I'm going to compare these to my pictures of my N370 ECU and see how close, if not identical, the two boards are. Any chance you could go one step further and get pictures of the backsides of the circuit boards so we can see the traces? If the boards are identical, that means that rom swapping is possible to make the ECU function for a different model. I would expect the pcbs to be the same, but a quick check wouldn't hurt. The pictures I have of mine seem to match the inside of your pics, with just the rom chip different.
If you're interested in sharing the rom, it's pretty easy to read to pc. I pulled mine using a hakko desoldering gun and read it with one of the cheapy cheapo amazon chip programmers. You don't want to expose the chip any more heat than necessary, and the desoldering gun does great for that. Then I just soldered the rom back in and its back the way it was. If you are new to that type of work, it would be worth practicing on some junk chips first so you don't ruin a nice ECU. I can also give you more info on how to do that. If you aren't careful, you can tear off some of the old circuit vias with the desoldering gun.
Other than the rom chip itself, this looks pretty much like the US S5 TII ecu. I got some pictures of a RTEK ecu and they had some jumper wires and removed components to make a different sized rom chip work. It wasn't just an rom swap. Blitz seems to have kept it clean with just a rom swap.
Cool find, thanks for the pictures, keep us updated.
comparing the BIN file to like an R-Tek or another ECU would be interesting to do. also a lot of these shops can still do these things. i don't know about Blitz, but Knighsports will reflash their ECU's still
If you think anyone might be interested in the BIN file, I can try to copy it from the chip and upload it to GitHub or something. Any idea what specific equipment I'd need for that? I'm more used to things like Arduinos (though I haven't used one in years), so I'm not sure what device I'd need to buy to connect it to my PC
Don't peel off that sticker! It blocks the UV window on the rom chip. Old rom chips that were rewritable had a window so you could wipe the chip using UV light. You must leave the sticker on or you could wipe the rom off the chip. The important ID numbers are visible, 27c256. It is a 256 kilobit rom chip, same as the N370 TII ecu for the US. As far as what the rom is, it would have to be desoldered and read to a pc.
Thanks for the pictures. I'm going to compare these to my pictures of my N370 ECU and see how close, if not identical, the two boards are. Any chance you could go one step further and get pictures of the backsides of the circuit boards so we can see the traces? If the boards are identical, that means that rom swapping is possible to make the ECU function for a different model. I would expect the pcbs to be the same, but a quick check wouldn't hurt. The pictures I have of mine seem to match the inside of your pics, with just the rom chip different.
If you're interested in sharing the rom, it's pretty easy to read to pc. I pulled mine using a hakko desoldering gun and read it with one of the cheapy cheapo amazon chip programmers. You don't want to expose the chip any more heat than necessary, and the desoldering gun does great for that. Then I just soldered the rom back in and its back the way it was. If you are new to that type of work, it would be worth practicing on some junk chips first so you don't ruin a nice ECU. I can also give you more info on how to do that. If you aren't careful, you can tear off some of the old circuit vias with the desoldering gun.
Other than the rom chip itself, this looks pretty much like the US S5 TII ecu. I got some pictures of a RTEK ecu and they had some jumper wires and removed components to make a different sized rom chip work. It wasn't just an rom swap. Blitz seems to have kept it clean with just a rom swap.
Cool find, thanks for the pictures, keep us updated.
I probably should've read this message before my previous reply lmao. I'll see if I can get one of those programmers, and will take a picture of the back of the board as soon as I'm home
Btw, any recommendations for a specific chip programmer on Amazon? One of the only ones I saw would be $72, which I don't want to spend just to rip some code
Last edited by gavinhogberg; Dec 30, 2025 at 10:23 AM.
About any flavor of TL866II would do it. That's what I use. Amazon's got a ton of them. I use it for reprogramming my Super Famicom games so they have English translations. I got mine for about $70 with a lot of adapters, but I'm seeing some cheaper ones on AliExpress. The only differences I'm seeing are number of adapters, which you wouldn't need. Just the basic unit and a USB cord would do it. I'd offer to do it, but shipping would probably be a wash with just getting a programmer.
Did you find someone to do your recap? If not, things have slown down for the winter and could take a look at it. I could also do the body cpu as well. That one is the one I have seen fail the most
