Celica Forums General Discussion Exterior reflashin computer ?

frd of mine said i need to reflash my car's computer after mods ?

Some people will very adamently say that this doesn't do anything, and it's all pyschological. Other people will say it's a must.

But you know what? One things for sure, it doesn't hurt- so who cares which of them is right? Just reflash it.

reflash?? what the heck does that mean??
What kind of mods are you doing that you need to "reflash" ur car?? if they're talking about resetting ur ECU(car computer, brain, etc.) then all you need to do is unhook the negative wire from the battery for 5-10mins then hook it back up..that's all..u should do that if u're installing Intake..dunno about exhaust or header, i'd do it anyway..

i have no idea wat reflash is ... but it's just wat you said ... then i can do it everyday (not tat i will) ...

well then ... 'reflash' after each mod or ... after all is installed ... (if i have all of them ready at once) ~

Because of the type of memory that is used in the ECU, reflash is actually much more of a correct term that reset; I just didn't bother correcting him *shrug*

You can also just remove the ECU fuse, thats even easier.

ok..got it..man just call it reseting ur ecu..most of peep on ecelica.com call it that way..

Resettin your ECU after changes does make a difference. good luck

What difference does reseting really make

^^^it suppose to work with ur new mods...kinda like adaptation sorta..that way you won't get CEL pop-up..

Basically, the idea is this... the ECU dynamically changes your settings based on what input it's getting from the sensors- but it's not "allowed" to change your settings too far away from it's factory defaults- where it started.

Numerically, lets say that your factory ECU came out of the factory at "5" and can only change +-2 (to 3, or 7, MAX). Lets say you do a lot of shit to your car, and the ECU WANTS to goto 1.5, but is stuck at 3- the lowest it can go. Resetting your ECU causes the ECU to set the factory default at 1.5; and then go +-2 from that point (0 or 3.5).

Like I said, personally I dont know if it's true, if the ECUs work like that. But it cant HURT

another MYTH ... i call it myth cause it's told by a frd of mine but ... to be honest i'd get the MYTH clear b4 i would trust him well here it is ...

he saids tat ... well reflash or reset ... i think we're talkin about reset here which requires simple replace of the ecu chip ... he 'claims' tat i need to MAIL the ECU chip to like some PLACE to alter it with WATEVER to fit my mod ... if not ... i would have to get those EXPANSIVE COMPUTER things to monitor my mods such as CAI for air flow ... or it will damage my engine ... ?

clarification plz ~

The real term "Reflash" the ECU is actually reprograming/remapping the ECU...

Just to let everyone know.. Celica ECU is "NOT" reflashable nor reprogramable...

Thats not entirely true, the celica ECU is remappable, like every ECU on the market it has to allow for variables such as air pressure, engine temp etc etc. Thats what all the sensors are for.

You can go in there and force new maps in it however, so that much is correct.

But you can try and get it to "discover" those maps.

there is nobody that reflashes our ecus. we do not have hondas there is no hondata type flashes which is what it sounds like your friend is talkin about.

now the power fc on the oher hand is an awesome tool. (refer to my sig) it allows you the ablity to change your ecus programming for maximum Performance and gains from all your mods.

he WAS into rsx so ... i guess ur rite tat he learned the reflash things from honda ecu ... altho he's gonna get WRX now ~

so the power fc thing make noticeable difference ?

an engine management tool, like the power fc, is godly on whatever car you have.

Our ECU's are reflashable, unfortunately Toyota hasn't been very forthcoming with the details of the flashROM in the ECU, or the methods used to program them in the first place.

I know there are people out there who will contradict what I say in this post, they'll say stuff like "I know a toyota tech, and so-and-so says the ECU is not reflashable." This is totally untrue.

There are two types of ECU's nowadays:

1) the kind with either a multi-pin connection to connect a programmer, or those which can be reprogrammed through the ODB2 connector. This is typical of Fords mostly, which can accept a programmer or an aftermarket program on a chip straight from the factory

2) those ECU's with a removable FlashROM chip which must be removed from the ECU itself, and re-flashed trhough an external reprogrammer.

Our cars use the 2nd method, BTW.

All ODB2 computers will utilize a flashrom in their construction, this way, if there was a major screw up in the factory progam, and technicians catch it in the future, a fix is as simple as reflashing the rom with an updated program (this is also used in PC motherboards, modems, videocards... You name it, it's a standard nowadays when it comes to software upgrade paths)

It is entirely feasible to reprogram the factory ECU, only problem is Toyota isn't forthcoming with specs on the ECU or how it's programmed.

The flashrom is there to retain the "learned" information about your driving habits, changes to the engine, Intake, exhaust A/F ratios, etc. This is why many piggybacks don't work well, since the ecu maps around them, and stores such changes in it's flashROM. Since there are certain aspects of the ECU that cannot be changed by default, a person with a flash programmer could theoretically change the ECU programming, and the ECU won't rewrite it, since it doesn't have the capacity to overwrite what it believes to be the stock parameters in the first place (even though you just overwrote them with a custom map)

Many companies, like Hypermotive, neuspeed and Diablosport have used this method before, but without knowing specifics about the ECU, it would be difficult for the inexperienced to reprogam it easily (hence why the PowerFC is so popular these days; it's ready to program from the get-go)

I have experience working with flashROM, I use it with old console systems to load a disk-based game ROM to specialized, rewritable cartridges to run software on the actual hardware for beta testing. Aside from that, I reprogrammed the ECU on my old Escort before, It was ODB1 (meaning, no actual Flashable rom, just a plain old flash-once ROM chip (not reprogrammable) So I needed to use an external, reprogramable plug-in ROM (which is sweet!)

Our ecu would need to be opened up (whic voids the warranty) the FlashROM chip removed from it's socket, plugged in to a PC-based reprogrammer (which you also need software for). You need to know the specifics of the sourcecode used on our ECU's to program them, and write a compatible ROM program, which is flashed onto the chip, which is then reinstalled in tthe socket on the ECU's board, and the enclosure is reassembled around the board and reinstalled. If the ROM is soldered onto the board (like on many VW's) you will need to de-solder the ROM and solder it back on after programming (which can be a pain if it's pad-soldered on there)

Most ECU's will use a chip socket, though, in case the ROM goes bad, it's easier to replace a chip than the entire ECU, makes it easier to rebuilt them too.

So, can it be done? the answer is yes.
Has it been done? the answer is yes.
Is it easily done by the home installer? the answer is possibly, it depends on if the installer has the needed hardware, software and know-how to pull it off.

If this sounds involved, don't be shocked, because it really is. Your best bet is to either go with a nice piggyback module like the Unichip, or with a new ECU like the PowerFC or the Brash Boy units. they are easier to reprogram, less involved labor-wise, and will probably cost less than buying a programmer box, all the software, and the computer to run it all. Plus, you need to be able to know how to decompile the factory ROM program and backwards-engineer it to write your own software for it.

Possibly worth the investment if you want to start a buisness reflashing ECU's, but not so much if you are a tuner looking just to readjust your maps yourself.


Brash Boy uses this method to reprogram the ECU, it's a factory ECU, with a different program on it's flashROM.

Damn... Big post

Yea.

I wish I had a Spare ECU, I'd love to tinker with it. I bet anything the flashROM is made by Yamaha. There stuff is proprietary, and costly. A new crossfader for my DJX-IIb cost me about $56, direct ordered from japan, and they are the only type it can use (no others compatible), it's quite a racket

You would just need a generic rom programmer, once you identify the chip used, and the code used (and how it translate into an actual map) the rest is easy.

It's definitely a challenge.

Any eggheads out there like myself have any info on the current celica ECU's? (Brand and size of the flashrom chip/type of processor/cpu speed, used, etc...)

If it's z80 based, I may be able to do something with it

It's got me very curious... I may start ECU hunting

Hell, even if I can't reprogram the factory ECU, if I learn enough, I could hunt around for emulated processors (many chipsets are already coded and available as open source) and plug the code int my own software: in essence creating a 2ZZGE ECU Emulator, which could be run on a PC or laptop, and interfaced through a paralell port to replace the ECU entirely. This can be done easily by backwards-engineering the ECU. code could be native PC code, only the output and input needs to be interpreted correctly.

You could definitely tune that in every imaginable way, a standalone pc does not have the limitations of the factory ECU.

wow ... damn ... the car things are gettin more and more complicated lol =P big educational post ... should pin or save a copy myself =P

What the hell is reflash? Does it involve a flashlight and you just shine it on the car or soemthing? I prefer the term reset because to me it means factory defaults or restoring to previous condition. Then again, i'm still just a n00b.

Just disconnect the ground terminal on the battery BEFORE you dissassemble and reinstall. You won't set off the CEI, so at least i'm told. Then reconnect and you're off. If you still get problems, probably because your hoses are crossed or something went wrong. CAIs are fussy sometimes.

uh read the posts above cause re-flashing was explained very well. lol

so i guess in conclusion ... i DUN NEED TO SEND MY ecu chip somewhere for mod ... i just do something with the wire and chip ... take it out and put it back ... ? ~

sending your ECU off will cause it to be reprogramed or whatever, which is better than reflashing/resetting.

Rave669...I just replaced the ecu on my Celi. Put in an ecu from a 2001 celi. So,I have an extra ECU that I'm selling.
This is a fully functional ECU from my 2002 Toyota Celica GTS 6 Speed. Engine: 2ZZ-GE. ($199.00)
These ECUs are definitely not this cheap from Toyota

Why did you replace your ECU?

California emissions laws cause the ECUs to be programed to be more restrictive and result in worse Performance.

?

Haulin_A_Doo the celica '02 ECU has a lower rev limiter as compared to other years

Interesting offer, unfortunately my car's a sportshift GTS. I'd take you up on the offer, but with any experimentation that I do, I would want to benifit my car in the long run. If it was from a sportshift, I'd definitely be down for it. Without a manual GTS at my disposal, it would be tough to try to back-engineer the ROM.

If anyone is selling a 2000 ECU from an Auto GTS, I would be very interested. That way, I could do the 2K ECU swap, and use my original ECU to see if I could pull the ROM and backwards-engineer it.

BTW guys, if you're looking for an EPROM programmer, here's a great source (be sure you read my earlier posts before you dive in to purchasing one of these though, it takes some know-how afterall...) the company is called DataI/O, and they make programmers for just about every type of FlashROM, EPROM, and any other type of programmable ROM out there:

http://www.dataio.com/

Well, Actually, I'd reccommend you send it in to a reputable tuning shop to do it. It's very involved and requires some specialized know-how, unless you are going with a piggyback computer or a stand-alone like the Power FC, you definitely want to get an expert to do the work on your ECU.

Make sure you ask the company that will work on your ECU if they can program a new ROM for your perticular application. As of yet, only BrashBoy seems to know how to do this, and they can be expensive.

Hopefully I can remedy this, so any reputable tuner (that can reprogram ECU ROMs) can do the job. The only thing holding us back is the lack of info on our ECU.

I will be sure to post more info as soon as I make some progress in my research.

i never did this reflahing stuff and i drove someone else's GT with just an Intake (same as me) and my car had more balls and no CEL so it depends if you believe it helps do it but i perfer to do it when a mod decreases Performance meaning my ECU needs to adjust...just my opinion

Uhm reflashing an ecu won't lower Performance. Your cars were probably the exact same; you were just more used to your own

^^^never said it decreases Performance

"I never did the reflashing stuff, and then I drove a car that was the exact same [that has done it] and my car was faster"

sic