91crxsi posted 01-10-2001 02:27 CT (US)
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Hi, All,
Listen up - I just installed a JRSC in my '91 CRX Si and it's great, but it got me thinking about an ECU upgrade for better performance. Well, all the aftermarket ECU makers (Zdyne, etc.) want to charge an arm and a leg for one of these boxes, and their whole business is based on the fact that we don't know enough about the ECU to do it ourselves. That doesn't seem fair, does it?
Being the curious type, I cracked open my stock ECU and did a little investigation. What do you think I found? Did Honda design their ECU around a proprietary chip? Not at all!! It's an 8051-compatible processor, and the 8051 is practically the single most popular microprocessor on the planet! At least it was - it's been around since 1980. Not exactly cutting edge technology here. And if you think about it, why wouldn't they use a widely available part when they're trying to mass-produce economy cars? The idea that Honda uses some highly sophisticated, indecipherable custom chip is just propaganda foisted on us by people wanting to make a buck on custom ECU chips.
Anyway, I happen to have access to an industrial desoldering station, an EPROM reader and an 8051 assembly language development system. Stay tuned as I expose all the juicy details...
91crxsi
PS - note: the information I'm divulging applies only to the '91 CRX Si ECU, as far as I know.
Spindle posted 01-10-2001 17:45 CT (US)
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So in other words, your gonna program an ECU for me? Or, write a computer program, and make a patch cable so we don't have to spend, oh, $900 bucks for it?
-Spindle
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88_SC_CRX_Si posted 01-10-2001 18:15 CT (US)
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Yes, keep us informed!!! I would like to get it on that.
"Noth'in like Induction...";)
-Ryan-
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91crxsi posted 01-10-2001 20:24 CT (US)
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The plan is - remove the stock PROM intact (not as easy as it sounds), read the program off it and try to make sense of it. I think this will take me a couple of months.
As for programming your ECU, let's just say that I'm not planning on making a business out of this. I'll be happy to share any info I can, but for the time being I'm not planning on doing this for a living.
91crxsi
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91crxsi posted 01-10-2001 20:36 CT (US)
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Hi, All,
Today's juicy tidbit:
The stock PROM is a 32 kilobyte ROM. The ENTIRE program to control EVERYTHING the ECU does fits within this chip. To give you an idea of how little this is, freecell, that cheesy solitaire game that comes with Windows, takes up 37K. A 32K mp3 file would play for less than 2 seconds. Over 40 different ROM images would fit on a floppy disk. More if you compressed them.
What's my point? Only that, while there are still thousands of lines of code to pore over, it's not millions. And it shouldn't take all that long to go through it. Expect weekly updates as soon as I get the PROM removed and read.
91 crxsi
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91SiNYC posted 01-10-2001 20:40 CT (US)
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you dont need to remove the processor...hondata.com makes a rom stacker that need to be soldered on top of the evisting ROM, and then you can hook it up to a desktop computer and read all the codes and fuel/ignition maps.....and change it all how you see fit....basically you program your own chip...ZDYNE bites ass! dont ever buy from them
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91crxsi posted 01-10-2001 20:45 CT (US)
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91SiNYC:
Why does ZDYNE "bite ass?" Also, do you have a Hondata ECU? I'd love to get a look at Hondata's or ZDYNE's ROM images some time, but first things first - gotta see what the stock program looks like.
91crxsi
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Steve Jones posted 01-10-2001 21:47 CT (US)
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I did a quick query for 8051 development at
http://www.topclick.com , and I found more sites than I can list here.
8051 development can be fun!
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davens posted 01-11-2001 01:23 CT (US)
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91SiNYC---have you tried a zdyne unit, or even a hondata unit for that matter? I'm just wondering because it seems you have some pretty strong preference for the hondata.
I'm sure you would base such a strong opinion on first hand experience.
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88_SC_CRX_Si posted 01-11-2001 08:54 CT (US)
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What's up with ZDYNE bitting?
Planning to get SECU this spring.
"Noth'in like Induction...";)
-Ryan-
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91crxsi posted 01-11-2001 17:07 CT (US)
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I agree that the ZDYNE SECU sounds sweet. If I had a spare $1,000 I'd run right out and buy one, too...
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91crxsi posted 01-11-2001 22:11 CT (US)
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TODAY'S UPDATE: "WHAT WAS I THINKING?"
Well, I just decided to go for it today. I was all set to a professional job of non-destructively removing the PROM from the ECU but after about an hour and a half of very careful desoldering, it was becoming clear that I wasn't going to get the thing out that way.
Desperate, I decided on more extreme measures - I found a pair of wire clippers and clipped the leads. WHAT WAS I THINKING? How am I going to get around without an ECU???
Anyway, I now have a loose PROM with trimmed leads, which I'm planning to solder onto a socket, so I can plug it into my EPROM reader. Will this madness work?? Did I already fry the PROM? Stay tuned and find out next time...
91crxsi
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davens posted 01-12-2001 12:20 CT (US)
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uh, you started hacking around with your ecu without having a spare and you need the crx for transportation? 1d10t...
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91crxsi posted 01-12-2001 22:16 CT (US)
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davens:
I have another car (otherwise, yes, that would be dumb).
Today's update: "Mission successful!"
Well, I removed the PROM yesterday and read it - seemed like everything was normal, until, upon closer inspection, every single byte was an odd value. That's odd.
I figured that the D7 pin of the EPROM wasn't getting good contact when I read the chip last night, so I re-read it again this morning and voila! I now have a copy of the stock PROM. Anyone who wants proof can leave me their email and maybe I'll send you a copy.
Cool. This still left me with an ECU missing a chip, though. So I cleaned up the empty spot on the PCB where the ROM used to be, soldered in a chip socket, went and bought a new EPROM for $3 at the local electronics store, burned the image of the stock PROM into it, and plugged it in. Checked all my contacts with a digital multimeter and everything was good to go.
The real test will be plugging the thing back into my car and turning the ignition!
Anyway, like I said if interested in a copy of the ROM, let me know. I haven't had time to really go through it to figure out what's going on, but I did check the fuel and ignition maps and they look clean (i.e., the data wasn't corrupted). I won't know for SURE until I get home and fire up the car.
The saga continues...
91crxsi
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91crxsi posted 01-13-2001 12:18 CT (US)
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Update: The car's running fine.
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SlowC posted 01-13-2001 16:22 CT (US)
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holy underware.. I wish i had the ability to do that! You plan on changing the codes?
Is that your next project?
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KSR posted 01-14-2001 18:06 CT (US)
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Hm... what a minute... If you can remove the ship and copy the original data back into a blank chip... can you erase and re-write another set of data onto that chip? Like a re-writeable CD? Hm.....
How much does it cost for this EPROM reader and writer? This sounds VERY interesting.... It's all a matter of trial and error to get a better fuel map, right? Or am I just dreaming?
Perhaps you can re-write the MAP sensor data to accept positive boost pressure. Wow.. the possibilities are endless....
PLEASE... let me know more... I'm very interested.. If you don't mind, please send me a copy of the EPROM data... I would love to see what it looks like.
Thanks
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simplecrx posted 01-14-2001 20:17 CT (US)
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This is exciting. I hope someone finds out how to reprogram the chips because I am totally down to pay for the reprogram at the fraction of the cost. Shoot . . . 92CRXsi, you could just go buy a ton of these chips and reprogram them. That way you don't have to worry about people coming back to you telling them that their ecu is screwed. I wonder if someone is willing to donate a zdyne or other reprogrammed chip so you can read the code and copy it. Hee hee . . .then we can all get copies. I guess I'm too business minded . . . all about profit. It just seems like a possibility to just copy the code from one that's already been done becuase zdyne has not copy righted their code.
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Mr Kwicko posted 01-14-2001 21:38 CT (US)
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If you're *NOT* thinking of making a business out of this, then maybe you should! It sounds like you're onto something, and I'll bet ZDYNE, et al, wouldn't be too happy about it. Just think: you could essentially reprogram or "rechip" ECUs for others at under $300 a copy, and you'd be making some serious jack in your spare time. At the same time, you'd be providing a very valuable alternative to the ZDYNE and similar chips.
As long as you've invested the time and the curiosity, you might as well get PAID for it, right?
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Dave_Darling posted 01-14-2001 21:56 CT (US)
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Keep in mind that copying the code from a Zdyne PROM is rather illegal. If you sell it for anything at all, they can sue the socks off of you. In fact, if you just give it away, they can also sue the socks off of you.
Come to think of it, even copying the Honda PROM may be illegal. I suppose you can claim "fair use" for one personal copy for a backup, but that would probably be pushing things.
If you want to reverse-engineer the PROM and figure out a program that's better, the more power to you! Don't expect it to be trivial, though. You'll have to figure out what part of it is code, and what is data. Then figure out how the data is used. Then re-map the data, and test the results. To really tune the ECU properly, a dyno would be the best bet. Lots and lots of dyno time, if you are making very many changes.
There are reasons that well-done aftermarket ECUs cost so much. They take a good bit of work to do properly.
--DD
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simplecrx posted 01-15-2001 12:25 CT (US)
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I asked my brother about EPROM chips and he was telling me that certain ones have security features that basically have a password encoded. Maybe zdyne does that. He was also telling me that where his lab(student for Mech E phd)there's things that read it. So I was thinking if anyone has a zdyne chip who wants to check out the code for "personal" use. I don't want to break any laws, but reading code and posting it on the web can't be illegal since it's only for personal use. Take for example, movies that you buy at home you can make copies if only you keep it at home. Along with taping football games, if you use for personal use, it's not illegal. So ideally posting the code is like posting the words to a song on the web as long as you're not making money or selling anything. It's considered free information right? If I buy a CD and take all the words out and post it, I'm not breaking any copyright laws.
Tell me if that sounds right? Like I said, this is interesting. I have an extra 88-89 teg ecu which I was gonna sell, but may contemplate about testing some stuff out.
Dave makes really good points, but then if zdyne is able to change honda codes, then it must be somewhat legal unless they have a contract with honda itself.
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7PSI CRX posted 01-15-2001 00:00 CT (US)
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Code is just code.
It's basically just a chart of injector pulse / ignition timing under variable conditions. (RPM, water temp, throttle position, altitude, O2 content, and such)
No one has a patent on a car running 18 degrees advance and an injector pulse of 170ms with a water temp of 170, throttle opening of 65%, at sea level, at 4500 RPM, Know what I mean?
[Edited by 7PSI CRX on 01-15-2001 at 01:24]
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weasley posted 01-15-2001 08:25 CT (US)
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I'm no computer geek (j/k!!) but instead of trial and error, could you write a CRX emulator? Then you could make adjustments to the code and see what it does to your 'soft' CRX before you plugin to your 'hard' one...?
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StorminMatt posted 01-15-2001 08:49 CT (US)
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Well, it is not surprising to know that it is so easy to read and program an EPROM for an ECU. The harder part is actually interpreting the code. In other words, how do the numbers in the ROM relate to actual engine variables such as degrees of advance, injector duration, intake vacuum, etc? I think this is what you pay the guys at Zdyne big bucks for. Not the actual removal and replacement of an EPROM. I don't know how easy this is. But I can tell you that as of now, Zdyne still has not completely cracked the code on 1992-1995 ECU's. So it can't be that easy to figure out. It would also appear that this information is top secret.
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Dave_Darling posted 01-15-2001 12:10 CT (US)
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Simple, 7PSI, those do not fall in the "fair use" category. If you keep the copy for yourself, you may be able to argue it. If you post it on the web (even for free!), you're breaking the law. Plain and simple.
Take this example: You buy a copy of Win2K. You read the data off the CD, you put it on a website so that anyone can download it. Does MS come after you? You bet they do!! And also everyone who downloaded it, too! Everyone who downloads a copy from your site is someone who doesn't buy from them. And they have the legal right to do that--you are breaking the copyright law by doing it.
It's the same with the code and data inside the PROM.
Look, I'm not going to tell you that you "can't" do something. I'm not even going to tell you "not" to do something. I am trying to inform you of the possible consequences of your actions, to let you make informed decisions. That's all.
--DD
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91crxsi posted 01-15-2001 15:20 CT (US)
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Hi, All,
I'm really glad there's so much interest in this project. And I knew that sooner or later, the issue of money would come up.
First of all, let me say that I never wanted to make a penny off this. I only wanted to prove to myself (and you) that it can be done. I'm happy that I've done that. I've never been good at just accepting it when someone says, "You can't do that." If the folks at Hondata and ZDYNE had not tried to reverse-engineer the Honda ECU, they would not be in business today.
I just thought it sounded fishy when they all said the CPU was proprietary. That makes no sense in a mass-produced vehicle. Honda is a car company, not a computer company. Why would they bother? And I was right. The CPU is 8051-compatible, and EXTREMELY common. The control code is less than 16K - puny by today's standards.
As for Dave_Darling's legal concerns, let me ask this - is it legal to take a copy of Honda's ROM, modify it, and SELL it? Can you imagine how far a computer software company would get if they said they could take your copy of Windows and modify it for you so it would be 30% faster, without signing some agreement with Microsoft?? If it is illegal, ZDYNE and Hondata are in deep doo-doo. I didn't modify my copy at all - IT'S COMPLETELY STOCK, byte-for-byte.
But suppose that it IS legal to modify the code/data, as ZDYNE and Hondata have done. Then why would it be illegal to disclose the location of the fuel and ignition maps, and how to modify them? Which, by the way, is what I'm planning to do. What you all do with that information is up to you.
As I see it, this is no different than taking Eclipse injectors and swapping them in for the stock ones, or swapping out I/H/E components. Is Honda going to come along and sue anyone who does it, or anyone who tells others how to do it? Give me a break.
91crxsi
PS - I guess I won't distribute the ROM image, for now. Besides, I've already told you everything you need to know to do it yourself. But please stay tuned for more info on the fuel/ignition maps, as well as some analysis of the program.
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Dave_Darling posted 01-16-2001 14:07 CT (US)
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> As for Dave_Darling's legal concerns, let me ask this - is it
> legal to take a copy of Honda's ROM, modify it, and SELL it ...
No, it is not. The legal way that things like that are done is by taking the specifications and the hardware that hooks up to whatever it is you're trying to "copy", and work out for yourself exactly what must be done to produce equivalent results. Then a different team of people take that information and design a piece of hardware/software/whatever that does the same job with the same inputs and outputs. It is an overly-complicated process, but that's the way that it has to work in order to not get hit with copyright suits. And that's one reason that aftermarket "chips" aren't a dime a dozen.
The story of how IBM lost the battle against "PC Clones" back when directly applies here. The way that the clone-makers succeeded was by doing the above process.
Note that Honda's copyright does not apply to the chip itself, merely to the code and data stored inside of it.
I think that the idea of decoding the Honda PROM is a fascinating one--even a worthwhile one. And I'm not going to call the cops in on anyone who does it--I'm not nearly that much of an ***hole. Like I said, I just want you to go into this with an appreciation of the possible consequences.
--DD
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91crxsi posted 01-16-2001 14:26 CT (US)
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Dave_Darling:
I appreciate your concern. I'm not interested in getting into any sort of legal mess. All I ever wanted to do was to crack that ROM and understand it. Ignorance has elevated it to an almost magical status, and as an engineer, I knew that was total bunk. And as far as revealing any "top secret" information about Honda's PGM-FI, think about it - it's written in 8051 assembly language, the PROM is NOT read-protected, and it's been out there for 10 years. Do you really think that the other auto manufacturers couldn't have done in 10 years what took a single individual a week?
Let me say this now: I'm not in this for the money. I'm not planning to spam the web with free copies of the Honda ROM. I'm simply going to go through the code/data and share what I learn about it. If you think there is a problem there, please let me know.
I know that I did say earlier that I would send a copy of the ROM data to anyone who was interested. I think that might not be wise. However, having said that, I do believe that if you already own a CRX Si ecu, then you, in effect already paid for the stock program. My data, then, might be considered a backup copy of a program you already paid for. Possibly you could sign some kind of agreement to the effect that you already have a copy of it and this is just a personal backup. We'll see. But again, as I said earlier, you already have all the info you need to do it yourself, and I will, over the next few months, share with you what I discover of the inner workings of the program.
91crxsi
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Dave_Darling posted 01-16-2001 17:33 CT (US)
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If you are really concerned with the legalities, I suggest talking to a lawyer. He might even tell you that I'm full of it--it woudn't be the first time!
If not, I'd think that you're too small for Honda to go after anyway. You can definitely claim that your copy is a "backup", and try to get it in under "fair use" that way. I don't know how well it would go over--but a lawyer probably would.
I'm totally out of my league when it comes to sharing general information about the code and data on the chip. If I offered anything, it would be pure guesswork. Again, an intellectual property lawyer would know, or would be able to find out.
I personally hope you do decipher the chip, and that you tell us CRX fans what's going on inside there. It's nice to have an appreciation for what is actually going on under the hood/under the passenger's feet. And I would bet that we are a small enough set of people that Honda won't notice anything that might technically be an infraction of their copyright. But if they do notice, and they want to play hardball about it, they do have the legal right.
I really don't want to rain on your parade. It sounds like a really cool thing to do!
--DD
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91crxsi posted 01-17-2001 15:54 CT (US)
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Update:
Hi, all,
Many of you wanted to know what type of chip I'm using. It's a standard 27C256 32Kx8 CMOS EPROM. The chip I removed was, I believe, 65 nanosecond, commercial operating temperature range (-40 to 85 C). The replacement chip I got was 55 nanosecond, 0-85 C. It's not exactly the same, but the access time is faster, which is not a problem, and living in sunny CA, I don't think the change in operating temp range will matter. I just went to the local electronics store and bought whatever they had in stock. If you look around you should be able to find a closer match.
Another thing - the ECU I have has a spot on the printed circuit board for a serial port connector, CN3. It's just next to the biggest IC. I don't know (yet) if the stock code supports serial communications, but obviously someone at Honda (or Denshigiken) was forward-thinking enough to include hardware support for it.
As for the code/data, I've found the location and layout of the fuel and ignition maps, and I have a fairly good idea of how they correspond to RPM and degrees of advance / injector duration. I've also gone through about 1K of the code, not that I completely understand what's going on there. I expect things to become clearer as I get a chance to see more of the program.
91crxsi
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91crxsi posted 01-18-2001 20:44 CT (US)
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Today's tidbit: Ignition/Fuel map location, and, The Serial Port - it works!
I said that I would tell you where the ignition and fuel maps are: the ignition map starts at ROM address 3DF3, and is an array of 15 by 17 bytes. The injector pulse duration map is in two parts, one starts directly after the spark advance map and is also 15*17 bytes, and the second part is just 15 bytes, from 3FF1 to 3FFF. I'll tell you how to interpret (and modify) them soon!
Also, the serial port. It looks as if the stock ECU WILL respond to serial communications, although in a pretty simplistic way - if you send it a nine bit number, it will reply with the RAM data stored at that address. For example, if you wanted to know what was stored at location 0F0, you would send 011110000 (in binary) and it would reply with the value of the data stored at location 0F0. So, in its stock form, the only thing the ECU's serial port does is give you read-only access to the 512-byte RAM chip. If you know how to interpret the numbers, though, that info could be quite useful. Hopefully I'll be able to do that soon.
ZDYNE (and I think Hondata) use the serial port to interact with the CPU in more sophisticated ways, such as uploading/downloading maps and the like. I suppose Honda engineers could have even used the same approach to reprogram their test chips, although the more likely scenario is that they used EPROM emulators.
As an aside, I bought a set of 450cc injectors today (from an old Mitsubishi Eclipse) for $50. They'd never work with the stock PROM, but with a modified pulse duration map...
91crxsi
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NC_Rex posted 01-18-2001 21:16 CT (US)
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You know these guys running the superpro Computers, the most widely used dfi-type computers, ...well they all share the code and code it here and there. Heck even when you buy these control systems like Tec-II and Zdyne, these ones that have the serial interface and are able to be modified with an upload, these come with base programs for your basic B16A, B16A turbo, NOS, etc...different engines, different years of Honda's. They comes with preprogrammed parameters for upload and to base your further work on with. So if you could get ahold of these windows programs and their software and watch the information come across or reread the reprogrammed PROM and compare it to the file with the lookup tables and data, then you could mostlikely draw a comaprable conclusion, and thus figure out what they do for larger injectors, and the this and that. Heck, I'd like to see if you could actually read a PG7 88-89 Teg ECU and PM7 88-91 ZC ECU and tell me differences on those things. You could probably then restack the information onto an Si ECU or HF ECU and test it out on someones ZC Hybrid CRX and see how well it works - in the name of research of course. Man way to go, your really onto something. Heck you just have to identify the blocks where the RPM limiter resides, and you can bump it up easily, maybe even give yourself a shiftlight from the ECU, just like the Rev-activated Zdyne ECU's that activate the VTEC, but just use it for a shiftlight. Man so many possibilities, have fun man. Let me know how it turns out man.
- Jon
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91crxsi posted 01-18-2001 22:31 CT (US)
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NC_Rex:
You know, there have been several people who have asked me about PROMs from other ecus. I never intended for the scope of my investigation to extend beyond my own.
However, that being said, if you people really are that interested, I'd be happy to take your ecu's and perform the same surgery I did to mine: cut out the old PROM, copy it onto a floppy for you, burn a new EPROM, solder in a chip socket, pop in the new EPROM and ship it all back to you (including your old PROM).
What would this cost you? I figure about $5 for parts (an EPROM, chip socket, solder and floppy), $10 for shipping and $15/hr for labor (about half of what I make in my real job). That should bring the total to around $45 to $60.
Remember, the new EPROM's program will be identical to your old one. I'm not going to get into modifying chips (not yet, anyway).
Also, and I must stress this, I CANNOT guarantee and WILL NOT be held responsible if for some reason I can't read the original chip!! So it's up to you. If I can't read the chip, I'll still go ahead and solder in the chip socket and send you a blank EPROM. That would be the best I can do, unless someone else just happens to send the exact same model ecu and I have it around.
This will be done on a first-come first-served, when-I-have-the-time, until-I-get-tired-of-it basis, so please contact me asap if interested.
91crxsi
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AbaZ posted 01-19-2001 03:56 CT (US)
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this is very interesting! hell I would pay you 100 bucks to do mine!
Jeff
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lotus911 posted 01-19-2001 08:59 CT (US)
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ME TOO!
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KSR posted 01-21-2001 12:07 CT (US)
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I'd pay you more if you can get into modifying the chip like a Zdyne.
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CRwreckz posted 01-22-2001 12:10 CT (US)
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Just a thought, what if you got a hold of a zdyne chip and read the program and compared it to the stock program, then you would know what is part of the actual operation and which regulate the rest. Not to say I'd pay a G to just rip it out and start probing around. I'm wondering, what are you using to read this? Is it possible to (or rather wouldn't it have been possible) to use a clip to take readings from the different points? If you do decide to send the code out email me,
coolio16@juno.com, I am more than interested as to how it is regulating settings and how it could be possible to squeeze more. CRwreckz
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91crxsi posted 01-23-2001 12:05 CT (US)
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Hi, All,
As I said before, you may contact me and make the necessary arrangements if you want me to do the manual labor for you (to read your PROM). Refer to my previous post.
Update:
Thanks to Scott (
TaeSoc@aol.com) for lending me his '91 CRX Si ecu and '90 PR3 ecu for further experimentation. As expected, the CRX ecu looks identical to mine, and I expect the PROM to be identical. The PR3, while physically similar, is very different inside. It looks like it uses the same kind of PROM, but the CPU is an OKI 66K series, which is not 8051-compatible. In plain English, the code for the PR3 can't be understood by a PM6, and vice versa. It also can't be disassembled by an 8051 disassembler. That's a bummer because 8051 disassemblers are easy to come by (free on the net) and OKI 66K disassemblers, as far as I can tell, are not.
Bottom line: reading the PR3 PROM should be no harder than reading the PM6. It's just the interpretation and reprogramming that could be more difficult. Also, I didn't see a serial port connector anywhere...
As far as my PM6 code analysis goes, I've gotten to about 2K of it by now (just a guess). Nothing really exciting yet, just diagnostics and housekeeping routines. I'll let you know when I find anything you might be interested in.
FUTURE PLANS
I'm planning on writing a Windows program that allows you to edit your maps directly, or rescale your injector pulse maps for different-sized injectors, as well as advance/retard your whole timing map by some constant, or a function or RPM/load. Not very sophisticated, but you have to start somewhere! I'm not sure what the best method would be - maybe just a Microsoft Excel spreadsheet with formulas! Anyway, what do you care, right? As long as it works! I don't have my own website, so I'll be emailing the working version to Steve Jones of the CRX Resource to post here.
91crxsi
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91crxsi posted 01-23-2001 22:21 CT (US)
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Here is a link to where you can buy EPROMs, EPROM programmers, even EPROM emulators for ultimate flexibility. Check it out, and start your own experiments!
http://www.transtronics.com/memory/EPROM.htm91crxsi
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7PSI CRX posted 01-24-2001 00:00 CT (US)
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Now that you can read and duplicate a chip, Can you modify it?
I'm really interested in Zdynes' launch control...
Throttle to the floor, engine only revs to 2500 while the clutch is engaged, let go of the clutch, and rpms increase.
[Edited by 7PSI CRX on 01-24-2001 at 05:08]
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KSR posted 01-24-2001 11:19 CT (US)
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91CRXsi. Now how hard is it to do all this programming, even with the equipment? The equipment looks cheap enough, but how much more work is it to crack those codes, especially for someone like me who just basically knows their way around windows, and that about it... I'm not good with soldering chips. So... how hard would it be?
Hehe... come to think about it... I think I wait for you to figure it out instead.
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KSR posted 01-24-2001 11:21 CT (US)
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Just a thought... would the Si ecu be able to process the excel codes fast enough?
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91crxsi posted 01-24-2001 15:20 CT (US)
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7psi:
Yes, I can modify it. Whether I can modify it to do something useful, well that's another thing.
ZDyne's launch control - it sounds the same as Hondata's. In fact, so many of the features of the two ecus sound alike that I often wonder if they are alike. Anyway, the logic behind it is not that complicated: if the clutch switch is engaged, choose rev limit A, if disengaged, choose rev limit B. All I need to do is find out where in the code the status of the clutch switch is being checked, and add that one extra little task. The hard part, actually, is finding it. Making the change shouldn't be that difficult.
KSR:
I hope we can all get away from talking about analyzing the Honda ECU in terms of "cracking codes," because that point of view is based on the myth that the information is somehow hidden and undecipherable. I've been trying to get across the point that the Honda program (at least for the 91 CRX) is written in MCS-51, which is the most popular microcontroller language in the world.
That said, it is true that it does take some work to read and understand assembly language programs, and it's probably beyond what most of us are really interested in getting into. That's why I'm taking it on myself, and why I want to explain what I find in simple, usable terms.
The Excel spreadsheet idea is not that the ecu will run Excel - that's impossible. What I meant was that you'd be able to enter your map data into a spreadsheet and Excel would calculate byte values which you would then edit into your ROM image and burn into your eprom. Eventually, I'd like to write a standalone program that can do the same thing, plus modify your ROM image for you, as well as scale the whole map for bigger injectors and stuff.
91crxsi
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91crxsi posted 01-24-2001 00:00 CT (US)
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UPDATE - ignition map calculations!
Someone (who will remain anonymous) showed me what ZDyne considers to be the stock PM6 ignition advance map, and based on this info, I've derived the following formula for calculating the byte value to put in the ROM for a given ignition timing:
BYTE = timing * 25/9 + 15,
where timing is degrees BTDC of advance. Since a byte can be anywhere from 0 to 255, or -128 to 127 for signed bytes, that translates into a timing range of either -5.4 to 86.4 degrees BTDC or -51.48 to 45.72 degrees BTDC. Ample range for any normal situation.
Example: at idle, advance is 18 degrees BTDC. Using the formula above, the byte value in the timing map should be:
18 * 25/9 + 15 = 60 (decimal value)
The stock map is a grid of 15 load points by 17 RPM points, for a total of 255 points. That would be pretty tedious to convert each point by hand, so I've created an Excel spreadsheet to do the calculations for you!
Here's how it works: it starts out with the stock PM6 data. You can then alter each point by hand and the spreadsheet automatically calculates the correct byte value to place in the ROM (it also tells you where to put it). The missing step is that you have to enter the data (don't forget to convert to hexadecimal) into your ROM editor and burn it onto your EPROM. Maybe I'll get around to writing this program later, too.
Anyway, I'll send Steve Jones of the CRX Resource a copy of the spreadsheet so everyone can get it.
Cheers,
91crxsi
PS - this is only correct if the ZDyne data was correct. Anyway, you'll be at least as accurate as a ZDyne user would be...
[Edited by 91crxsi on 01-24-2001 at 22:07]
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NC_Rex posted 01-25-2001 02:25 CT (US)
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HondaHackers rule!
Yeah I can send a ZC ECU for you to dupe. I just don't know about all you said.
However, that being said, if you people really are that interested, I'd be happy to take your ecu's and perform the same surgery I did to mine: cut out the old PROM, copy it onto a floppy for you, burn a new EPROM, solder in a chip socket, pop in the new EPROM and ship it all back to you (including your old PROM).
What would this cost you? I figure about $5 for parts (an EPROM, chip socket, solder and floppy), $10 for shipping and $15/hr for labor (about half of what I make in my real job). That should bring the total to around $45 to $60.
I was thinking more like, $5 for the ship - I would buy to make things easy on you, $15 for shipping both way because I am helping you out by giving you the prom program because I am a nice guy and think Honda owners should have a cheaper alternative and I know you'll uphold that, and if you break my ECU I will be very pissed, but won't bother with the $15 per hour because then you would be doing charging me for giving you a favor and I want my ECU back - your not doing me a service, so why would you be charging me?? Kinda follow? I am helping you out giving you an opportunity and paying $20 out of my own pocket for something my ITT graduate brother that works for Motorolla can do on his handheld! So please don't think I am paying you for your work, because I'm just doing you the favor.
Just let me know. If you do a good job, I may just let you borrow my Spoon or STEC PR3 ECU's that I brang back from Japan.
- Jon
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91crxsi posted 01-25-2001 00:00 CT (US)
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NC_Rex:
If your brother can do it for you, I suggest asking him. I've already been lent a stock PR3 and I'm in contact with owners of teg ecu's and even the ZDyne, not to mention the work I'm doing on my own ecu, so my plate's pretty full at the moment. If you want to do me a "favor" and send me a ZC ecu to look at, that's fine. But I'm not particularly interested at this time.
Thanks, anyway,
91crxsi
PS - come to think of it, if you really want to do me a favor, save your $20, have your brother read your PROM for you and email me the image.
[Edited by 91crxsi on 01-25-2001 at 15:53]
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gavnook posted 01-27-2001 12:53 CT (US)
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One little thing: I think all that talk about hondas having these uncrackable computers and crap is just based on the fact that they've never, to my knowledge, built the ECUs to be easily changeable. Perhaps I'm wrong, but I think other car companies, GM especially, have built their computers with replaceable chips. I wouldn't be suprised though if aftermarket GM computer stuff was little more advanced than that. However, this is based on vauge memories of when I used to get Hot Rod magazine.
I am completely amazed how simple this is. They had me fooled. I think the main reason ecu mods have been so slow comming is that you don't find a lot of people with a lot car-tech knowledge who know anything about programming microprocessors. Also, how big do you think the market is? Yes there are thousands of hondas with fog-lights and 17" wheels, but how many of their drivers know what an ECU is?
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locash1 posted 01-27-2001 01:11 CT (US)
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I've been following this thread for awhile, and find it rather interesting, so I will continue to read it.. I have been into the ecu reprogramming game for about 2 years now, and have learned quite a bit of information, most of which gained by analyzing the stock ecu and others modifications to it. I own an all options Zdyne SECU and multiple "every option listed" Hondata ecu's, and am an authorized Hondata installer/reseller. Also, I do honda/acura ecu reprogramming as a side business. I'll give you a small bit of information, just to save you the trouble.. The Zdyne ecu uses an encrypted processor to handle most of the work, the EPROM is replaced with a battery backup EEPROM unit, for flash programming, which is VERY slick, and also, non-duplicatible. The hondata unit is a different game altogether, storing a large part of the information on an encrypted PIC chip on a separate circuit board, which basically allows the unit to use the other maps that the user burns into the replaceable eprom. Anyway, what I am saying is that you cant just "copy" either of their work, not only is it illegal, but it is encrypted. Anyway, I wish you luck in your endeavors, and I applaud the effort given, obviously there is one person in the group that is doing it for fun and to help others out with this technology.. If ecu reprogramming didnt pay most of my bills, I'd be giving the info out for free also, but currently, I cannot afford to do as such.. But, I am in no way going to attempt to stop the efforts, as I was once in your shoes.. In fact, I am even willing to help the person spearheading this project, by giving him some rom files to study, and maybe a few pointers if needed..
Anyway, good job guy(s), and welcome to the world of honda ecu reprogramming..
-joe
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91crxsi posted 01-27-2001 00:00 CT (US)
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I'd appreciate any info you can share, Joe! I think that, when most of us think of aftermarket ecu's, it's ZDyne, Hondata, Locash, Spoon, am I forgetting anyone? There aren't that many players, are there?
From what little I know of the ZDyne SECU, it's obvious that their setup was well thought out. They are fortunate Honda wasn't as security-conscious as they are, or my guess is they'd still be trying to make a viable product. And for those that just modify the PROMs, that niche wouldn't even exist.
I hope that we can de-mythologize the Honda ecu. It's just a dedicated computer with less computational horsepower than a dinosaur PC. It's not magic. At the same time, however, let's not deprive the aftermarket ecu/chip vendors of their *fair* wages. The service they perform is no different than an auto mechanic. We pay them because they have the special tools and expertise. If we had the skills and equipment they did, we could do our own repairs. But because we're either unable or unwilling to do it ourselves, we pay them. That's just the way it is. I don't believe that, even with the information I'm divulging, there will be that many people that will bother doing this themselves.
91crxsi
[Edited by 91crxsi on 01-27-2001 at 03:52]
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7PSI CRX posted 01-27-2001 08:45 CT (US)
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Do it myself?
No way!
What I would like is to have:
An ECU with a replaceable chip. (snap in, with different programs on each chip) You can do that now, correct?
How much would an individual chip like that cost?
Or an ECU with a chip that can by modified in car via uploads. (ZDyne)
Snapping in a different chip would be no problem, and having a few different "programs" would be really awesome.
Updating a chip via PC I think would be a little more complex, unless, like you said, you can easily copy spreadsheet values into the "Right Place", and had a backup copy of your original program in case of mixup or problems.
Both should have "fail-safe" modes.
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91crxsi posted 01-27-2001 12:59 CT (US)
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7PSI:
I believe we can do that. As of today, I'd know how to modify the ignition map for you. Soon, I hope to have the injector map figured out. I already know that you can modify the program from a PC using an eprom emulator, although I'm not sure I'd want to be tooling around town with an emulator plugged into the socket instead of a real chip. Should be ok, but...
Anyway, that would be the easiest way of having a PC-modifiable program.
Once I get the injector map figured out, I'll post it.
91crxsi
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KSR posted 01-27-2001 19:46 CT (US)
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91crxsi.
I just can't wait till you figure everything out and create a program to modify the fuel maps, etc.. just like the Zdyne.. that would be amazing... I woudl purchase one off of you right away...
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locash1 posted 01-27-2001 20:02 CT (US)
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I don't actually make fully programmable ecu's for the public, as I am not a software programmer. There is one fully programmable honda ecu of mine out there, and it works lovely and reads/compensates for boost, but it was VERY time consuming, and I am not willing to make another.. On the other hand, I do basic reprogramming of honda/acura ecu's, by analyzing the code, and using products from Techtom to find items that I wasn't previously capable of. There are some really cool things you can do with a honda ecu, it all comes down to how much time you want to spend figuring it out.. Most of my research has been with the dohc vtec ecu's, since those are the motors I am interested in, and deal with on a daily basis.. Back to the topic, since I havent spent much time with the sohc ecu's, I am curious to see what you figure out. By the way, those of you that want a fully programmable honda ecu should really look into the Zdyne and Hondata units, you'd be amazed at what they can do for the price..
Also, as a reply to Matt Storm's previous post (note: I am not out to make Matt Storm look like a clown, I just disagree with most of what he has to say), Zdyne knows all about the 92-00 Honda ecu's, and they have a fully programmable unit out there in a forced induction 99 Civic Si right now, but since there is (1) person doing all the design work (Bill), as well as trying to keep up with current orders, and run another business that actually pays the bills, at the same time, AND have a family life, its just going to take time before the product is released to the mass public.. Understand what I am saying here? Please don't make assumptions and relay them as correct information, as it just makes you look foolish when the truth is revealed.
Sorry, I got way off topic there, but I had to vent. Back to the games.. 91crxsi, feel free to contact me if you are in need of any rom files, and no, I wont make you desolder my ecu's to get them.
And for those of you that suspect it, yes, I work for HASport also. (day job)
-joe
locash@locashracing.com IP:
killerb posted 01-28-2001 16:53 CT (US)
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just a note on the copyright thing:
If you take a copy of any code and use it for personal use no one is goning to care if you have it unless they are really nuts. If you send code to be looked at ie. an original copy of the honda code on the eprom chip then there is nothing wrong with this think of it as you would borrowing a book from some one, tecnicly you should go buy the book bbut instead you borrow it and don't pay anything for it.....this is the key point If you were to SELL copies of the code then it is illegal but if you give the code away then there isn't a problem because you are just sharing information.
Is there anyway someone can send me a copy of the original code, for my personal use I would like to have a back up and possible look into the actual code when I get a little further in my studies here in Canada
thanks
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killerb posted 01-28-2001 17:00 CT (US)
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hey,
if the ecu is just a dinosaur computer what about building a "newer" one with custom case that could fit say under the seat or in the trunk that was hooked to a small screen in the dash, that way you could build it out of like pentium stuff that you can get for like next to nothing from various stores etc. I remember seeing a guy that built a mp3 system for his car and custom built a computer for it using like old 486 stuff.
just think of it as a way to change programs like have a program for true out power and have another for fuel economy and another for different conditions the possibilities are endless.......or maybe this is all just fluff from my brain that only will work in my dreams.
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CRX150 posted 01-29-2001 02:57 CT (US)
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Oh yes Please E-Mail me with your finding so far I have an 86 Si and an extra Ecu That I would love to play with I have little to lose, my total investment in my CRX ahs been $150.00 and I'm not afraid to play!!!!:-)
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91crxsi posted 01-29-2001 14:30 CT (US)
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TODAY's UPDATE: The PR3!
I managed to read a PR3 PROM over the weekend. I haven't actually verified it by running a copy on the car (a friend's B16A), but it looks pretty clean to me.
Anyway, the big news is that the fuel and ignition maps look like they are the same format as the CRX's! Not the same curves, but the same format (15 by 17 and all that). This makes me wonder if ALL Honda ecu's use the same format for their maps. So, understand one and you understand them all! That would be awesome.
Thanks to all you guys who have supported my research with donated computers and files. This is turning out to be bigger than I ever expected...
Finally, let me reiterate that it's not about the money. I'm not trying to take the "spoon" out of anyone's mouth (pun intended). Sure, I'll consider doing a favor for a friend here and there, but I'm really only interested in learning, not selling chips. My offer to read and socket your ecu's is still good, but please get your aftermarket chips/ecus from the vendors who rightfully own them.
91crxsi
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SlowC posted 01-29-2001 16:47 CT (US)
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91crxsi
I've followed this every since day 1... I wish i had the knowlegde and know how. I have looked EVERYwhere and would like to know where to start so i can learn this on my own. Instead of bugging you and taking up your time. Please any help would be appreciated and i will be very thankful!
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91crxsi posted 01-29-2001 18:22 CT (US)
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SlowC:
Well, the web is your friend. Not every Honda ECU is run by an Intel-compatible chip. Some are OKI nx 66K. But quite a few are Intel. Like mine, an 80C154. I think some early teg ecu's and the 88-89 CRX ecu's use an 83C154, which is the same as mine, except the PROM is contained within the same chip as the CPU. So, it's not exactly true that these ecu's can't be "chipped." It's just a lot more expensive, equipmentwise. An EPROM reader/programmer can be had for around $150, whereas a CPU programmer (what you need for the 83C154) is going to be $500+.
Anyway, as I was saying, the web is your friend. For spec sheets on your CPU, goto Intel.com. That's also a great source for info on the MCS-51 family of microcontrollers. Especially info on the instruction set and whatnot.
Next, grab some free tools, like a disassembler, which is a must if you want to analyze the code. My personal favorite (so far) is dis8051, which not only disassembles 8051/8052 code, but also includes a list of cross-references or memory locations. This is great to get a feel for which subroutines and lookup table locations are more important to look at. Also, a good hex editor makes looking at and changing maps a lot easier. For this, I like WinHex. You can arrange your data in 15-byte-wide rows, which is perfect for the maps, and it tells you what the value of each byte is in 8-bit unsigned integer values.
Of course, the most important thing, if you plan on doing anything with this info, is to get an EPROM programmer. Here again, the web is your friend. Just do a search for "EPROM programmer" and you'll find tons of them. Any one that can handle a 27C256 EPROM (i.e., probably any one that can program a 28-pin chip) will do.
Then buy yourself a soldering iron, eprom, chip socket, solder, needle-nose wire cutters for cutting out your stock prom, maybe some kind of solder sucker. And a floppy for your ROM image once you get it...
So that's it. EVERYTHING I needed to know about this, I found on the web. So it's out there. Just gotta go and get it.
Best of luck,
91crxsi
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7PSI CRX posted 01-29-2001 19:37 CT (US)
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I've been following your posts also.
Great stuff! Keep it comming!
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SlowC posted 01-30-2001 16:52 CT (US)
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91crxsi:
Thanks for all the great info. I was just stumped on how many pins the ECU chip had and the names and codes of them all. You gave me ALOT more info then i was expecting.. thank you!
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91crxsi posted 01-30-2001 21:51 CT (US)
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TODAY'S UPDATE: CRX MAP CALCULATOR!
Hi, folks,
Previously, I posted a message that I had figured out how to program the ignition map. Now, I've got the injector map figured out. I've created an Excel spreadsheet that allows you to enter in the desired ignition timing and pulse duration and it calculates the byte values to enter into your ROM. It also shows you where to put them. With this little tool you can create your own custom CRX maps any time you want!
The calculation of the byte values for the pulse duration map is a little more involved than for the ignition map, so I'm not posting it here, but you don't really need to worry about it, since the spreadsheet will do all the work for you.
I'll wait until I get a bunch of separate requests for it and then I'll email it to everyone at once.
COMING UP SOON: ARE ALL HONDA ECU MAP FORMATS THE SAME?
stay tuned (pun intended),
91crxsi
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killerb posted 02-03-2001 09:21 CT (US)
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Hey what kind of place would use these eprom readers? I want a copy of the code but don't want to spend like $1000 bucks on everything needed to get it.
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91crxsi posted 02-03-2001 19:55 CT (US)
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killerb:
I'm not sure what kind of place has these readers. I know my workplace has one, and I'm sure the chip dealers all have one. Actually they are fairly inexpensvive - maybe around $150. If you go to an electronics store, you can sometimes rent them, as well. But I think that $150 is a small price to pay, especially considering that you will NEED one if you plan to program any eproms yourself, and you'd probably pay at least $150 to have someone else do it for you.
91crxsi
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91crxsi posted 02-05-2001 21:29 CT (US)
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Today's Update: I'm still here...
Some of you have wondered if I'm still around because I haven't posted any new info in a few days. Yes, I'm still here, and I'm still looking through the code. It's just that it's pretty slow going and I haven't found anything particularly exciting in the past few days (unless you call a multi-byte multiplication routine exciting).
So far, I've gone through about 1/4 of the code. That probably took me at least 15 hours. I'm not exactly a whiz when it comes to reading assembly language code with no comments and only a vague idea of what it's supposed to be doing. Anyway, whenever I run across something that might interest the casual observer, I let you know. It's just that lately, there hasn't been anything to report.
One thing I can tell you is that I've had the chance to compare stock vs. aftermarket versions of both the PM6 and PR3 and, byte-for-byte, there's very little difference between them. I'm pretty sure I know where the bytes that set the rev limiter are on the PM6, but I don't know how to interpret/set them yet. And on the PR3, I'm down to about 5 different possible locations. It's a little harder with the PR3 because I don't have an easy way of knowing what's code and what's data. On the PM6, I just look at the disassembler output and it's pretty obvious.
more to come,
91crxsi
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SlowC posted 02-09-2001 15:37 CT (US)
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Anything new ans exciting? I have looked and looked for days but no new info.... I hope everything is going smooth...
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cingham posted 02-12-2001 14:49 CT (US)
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ooohhhhh aaaahhhhhh I read this whole post, I crave more 91crxSi keep cracking and I'll start gaining a small force of Si ECU's. Than we can under-cut the big dawgs and buy NSX powered CRX's
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bodiby posted 02-15-2001 17:18 CT (US)
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I have looked at the code of what is supposed to be an upgraded ZC program and I can find the maps. I will soon have a stock ZC program to compare against (unless my freind destroys the chip).
Has anyone found info for the OKI processors (ZC uses OKI not intel)? Assemblers, compilers, etc? I know it must be out there, I just haven't looked hard enough.
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SlowC posted 02-19-2001 17:30 CT (US)
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Well I designed a selector switch for the ecu, with the flip of a switch, you can choose stock/performance, stock/stock or performance, performance. This will be good for emissions and then racing all in one. I want to make a test switch soon!
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91crxsi posted 02-19-2001 19:53 CT (US)
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Hi, All,
I'm glad to see that others are getting into the act and trying out their own experiments. Best of luck to you all!
I'm just writing today to let you know that this thread is not dead, although I have been away for a while. I'm still going through the PM6 code and I'm between 1/4 to 1/2 through it. I'm currently going through the code in the $3xxx range and it seems mostly to be math functions and A/D access. Not much to excite the average Joe.
If I get any leads on programming tools for the OKI chips, I'll let you know.
Thanks for your patience and continued interest,
91crxsi
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91crxsi posted 02-22-2001 21:04 CT (US)
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Today's update: Does the stock PM6 have a bug??
Hi, all,
Well, analyzing assembly language code is about as exciting as watching paint dry, but every so often something interesting comes along. I've gone through about 5K out of 16K - and this is after about a month - so it will be a while before I'm done here.
The latest interesting bit of trivia is that there appears to be a bug in the stock code (that's what it looks like to me, anyway). There's a small snippet of code that seems to be written to read a value from a specific memory location, do some tests on it and return a modified value to the same location it came from. The problem is, instead of reading from a location, it's loading an absolute value. So it would be doing the same thing every time.
I'm not far enough along to be able to tell what this code fragment is used for, so I don't know offhand what the impact of this bug is. But I'm pretty sure it's wrong.
For those of you not particularly interested in programming, check back in, oh, 2 months or so..
91crxsi
PS - rest assured that something more substantial and exciting is on the way..
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AL posted 02-24-2001 15:30 CT (US)
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hi there 91crxsi,
It is really long time no see, I am really glad that u are back. Just wonder is your e-mail at yahoo still work? I try to e-mail u couple time but no reply?
Anyway, I have some progress on the Ign map, I made up a spreadsheet and did some alternations on the mid range of the Ign mapping and also did the checksum insert.IT WORKS!!!!! with no Engine lite.The car reponse time is a lots better than before and that probably due to the retarded timing of the stock Ign mapping.I guess the next step is just need to make a more agressive Ign to perfert it then I will start try out the Fuel mapping.
There is also something I find, remember there is a NEC big chip with BACK-XXXXX on top that we are not sure what it is before. It is probably a back up programming unit. I try to run the car without the rom. The car will go into limp home mode but it is still driveable.
On the last post u saying u can access the ram by input some data into the certain address and there will a response from your input, what tool(s)did u use to do that?Emulator?? I would like to hear from u if is ok
?
Just wonder did u try out your Mitsu injector?? Hope it will work. I notice the pattern on the PM6 Fuel map,corret me if I am wrong. The valves seem to me are "off time vs on time"(pulsewidth) in that row of 15 LOAD point? Does it have any fomula u can use to create this kind of pattern?
Last thing, can u also tell me where is the rev limiter and map sensor location on the PM6 or even the pattern will help. Really greatful u are here to help us out.Thanks again.
Good luck all.
AL
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silver88si posted 02-25-2001 02:12 CT (US)
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i have a question for u guys
i put a b16a1 jdm ecu in my 88 crx si
it ran fine and it seemed to be a faster
i threw codes but it ran fine
why did it work.
i also used a 90 crx si ecu and it was no different even though there is an extra sensor on the back of the intake manifold
on the 89-91
i threw no codes at all
also why does the 89 integra ecu always seen to throw code i which is the oxygen sensor.
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ClubSiRacer posted 02-27-2001 00:00 CT (US)
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Interesting work being done here... I just wonder how it may work with newer ECU's? Did Honda decide to use the same programs & PROM's with their newer ECU's or are they more involved? Perhaps someone will be willing to donate a newer one for "testing".
While i'm asking, someone here surely has to be famaliar with the Hondata system. I was told you needed a burner to make changes where as the Zdyne uses a serial cable to upload changes directly. Has anyone read about the new LINK system for Hondas?
http://www.carmodifications.com/Link_Po ... plugin.htmOh, and i'm looking to buy a used ZDYNE SECU Gold if anyone is selling one. Please email
siracer@clubsi.com[Edited by ClubSiRacer on 02-27-2001 at 22:40]
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91crxsi posted 02-28-2001 13:55 CT (US)
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Out of curiousity, did you replace the MC too, or just the 28 PIN ROM chip? I'm still waiting on the friggin' AT89C55 chip to get here, so I can test my stock ROM image in it, but I ordered it last Monday with the 2nd day Air option, and well, it hasn't gotten here as of yet, due to our current crisis. I've got the 88 ECU if you remember, so I have to replace the whole MC, and I am HOPING that the AT89C55 chip will suffice. Keep us posted on your progress!
