ECM to PCM upgrade

Discussion in 'Injection Tech' started by Bill USN-1, Jun 13, 2011.


  1. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

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    Decided to knock the dust off this old project!

    Back in about 05 or 06 I worked with a few guys on thirdgen doing an upgrade from the old reliable ECM 8746/7747 to the later 95-95 TBI truck PCM. These are the same PCM I just used in the MPFI install. There are several versions used in TBI trucks and CPI trucks and vans with the 4.3. The main ones are the 8625 and the 7427. There are code difference in each application but all of them can interchange.

    Back when I did this I was just looking at the latest hot thing. But at the time it just didn't seem worth it with all the ECM's avail and they still work perfectly fine on our old motors.
    So I didn't feel it was worth doing a writeup at the time.

    Well since I am using this PCM for the MPFI I figured I would show some of the versatility it has.

    Back then I made this little crossover adapter so I can simply plug the new PCM into an existing ECM harness. This adapter isn't needed and actually takes more time to build then just swapping pins on the harness. But it does allow me to test ECM's, PCM's and chips in the same vehicle.

    The big advantage and disadvantage to this PCM is amount of code it has. There are so many tweaks that can be done that just about any mod you want to perform, it can handle it.
    Electric fans, wide band O2, turbo, electronic overdrive tranny....etc
    As I get time I will be documenting most of these in my various project builds.

    I'll also be adding all the pin changes required to swap this in.

    So stay tuned as I progress through some of my projects.

    First the adapter I made:

    [​IMG]

    [​IMG]

    With the PCM plugged in.

    [​IMG]

    Plugged into my old 72 TBI travelall.

    [​IMG]

    Using Tunercat to log a little data and make a few changes.

    [​IMG]
     
  2. Julian 537

    Julian 537 Farmall Cub

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    Great thread Bill.

    I look forward to hearing more about this.
     
  3. JeepsAndGuns

    JeepsAndGuns Farmall Cub

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    I am having a hard enough time with the simple ecm I have now to worry about doing any swaps to a more complatated one such as this one, BUT just for the sake of pure conversation, I have a few questions.

    You say it can controll cooling fans? I was just thinking the other day about electric cooling fans and was wondering if the 7747 could be used to turn one on and off at specific temps. I didnt see anything on the wiring diagrams for the 7747 for it, so I assume not.
    Then you say this one can use wideband O2 sensors? So if one was to want to install one, then you wouldnt need to buy a seperate WB O2 controller like you would if you were to stay with the 7747 type ecm's?
    Does tuner pro support these, and is the programming actually more complacated, or is there just more stuff in there you can change
     
  4. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

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    The 7747 can't control fans or as you said, it would be in the FAQ's.

    The pcm does have about 4X the code. So if learning 4X more is not more complicated then nope, it's all the same.


    Yes tunerpro does support all these but as with the learning curve, you either need to learn how to write the definition file for data logging with tunerpro to read the WB or you need to hope someone else did it before you and was nice enough to post it publically.

    The actual pcm code has to be changed to make the pcm operate them. most are well documented online but you need to have a small understanding of the hexadecimal addresses to write the new code into the old bin.

    I'll cover most as I get to them.
     
  5. JeepsAndGuns

    JeepsAndGuns Farmall Cub

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    I will definately be keeping a eye on this. I dont care anything about auto trans controll, but the possiability of using a WB O2 and being able to controll cooling fans seems like cool features.
    I was at the local pull a part looking for some other parts and like I am, I take closer looks at every chevy/gm trucks and vans looking for spare parts or complete good harnesses, so far they have all been hacked real bad by other people. But I did find a 93 astro van with the 16168625 ecm. And since they are cheap there, I just went ahead and picked it up to toss in the back of the parts room as a WAY down the road future project. The harness had already been hacked under the hood, so I saved the plugs for the pcm and about 6-8 inches of the wires.
    These are definatley diffrent beasts. I did a little looking and reading about them on moates. From what I looked at mine and read online, it appears the limp home chips are not removeable from the memcal, and the one I have is a V6 (BFMY) So I probably should have just left it and looked for a V8 one. But oh well, it was cheap. Are you running moates G1 adapter?
     
  6. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

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    You can adapt any of them to work. Just set the cyl count.
    Limp home can be modified for MPFI(see the MPFI version 1 thread).
    I am running a moates adapter right now but you can also just cut the original chip right off and solder a standard 28 pin socket on. then you can drop a 27sf512 right in.
    Or plug a zif socket into the 28pin socket if you prefer.
    It's all pretty straight forward.

    The MPFI install write up that Gravedigger did is an 8625 V6 PFI ecm.
     
    Last edited: Jul 1, 2011
  7. JeepsAndGuns

    JeepsAndGuns Farmall Cub

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    I searched and read your MPFI version 1 thread. Very interesting. Thats pretty neat you can simply soder in one jumper to convert it from V6 to V8. I know you could change the bin, but didnt know you could do that to the limp home chip. I figured it would be easyer to start with a V8 bin than a V6 bin. But seeing how the eproms are sodered in place how would one read it to get a stock bin file that you could then tune? Or do you have to rely on finding one somewhere online to download?

    That PCM I pulled, I can not remember what injection it had. I just glanced at the engine, but didnt pay any attention to it. So I dont know if it was TBI or port. Can you tell from the BCC? I dont have excell so I cant open your BCC lookup file. I tried to google it, but had no luck. Its BFMY.
     
  8. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

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    BFMY=1993 astro van with 4.3(LB) man most LB's were TBI but it really doesn't matter since you will be removing or bypassing the stock chip anyways.

    There are many bins avail in the file upload section of Moates. You could probably cut the chip off set it in the burner and read it.
    If I had a specific bin I wanted that wasn't in the file section already then I probably would.
    But most any you need are avail there.

    You can use Open Office for a free look alike of MS Office.

    There's been a couple guys copying all the bins and posting them on their own site but if they have them then they are avail. I have a couple links in the FAQ's.

    The MPFI threads are in the FAQ's so no need to search.
     
  9. Jon In Tucson

    Jon In Tucson Farmall Cub

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    According to the BCC lookup file, your BCC is from a 1993 chevy with 4.3, manual trans and whatever ratio GU5 rear gears are...


    BFMY 1993 34016 16192233 16168625 2234 2235 L1 LB4 4.3 MAN GU5


    I haven't ironed out all the bugs in my own project, So I have great respect for anyone looking into the MPFI project. God Bless.
    Jon In Tucson
     
  10. JeepsAndGuns

    JeepsAndGuns Farmall Cub

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    Exact same here. I am nowhere near doing anything like this right now, I am having enough trouble with the simple 7747 ecm system I have. I only bought this pcm just cause I found it and it was cheap. I have stuck it in the back of the parts room as a future project, for when I get way more educated on all things injection tuning. I will contune to watch and learn from bill and let him iron out most of the bugs as he goes along.
     
  11. JeepsAndGuns

    JeepsAndGuns Farmall Cub

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    Wait, this just hit me. You say that BCC comes up as a manual trans. I pulled this from a 93 astro, but it was most definately a automatic. Humm
     
  12. EagleMark

    EagleMark Banned

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    There are many mistakes in the BCC lookup linked to from the FAQs here. Looks like the same mistakes are in the BCC lookup from Moates website as well. Although it is usually helpful! I bought a SnapOn book off eBay that verifys these mistakes and also lists the recalled updated chips if you need one checked just PM me the BCC and I can verify correctly what it is and if it was the latest chip for the vehicle from GM.

    Since I've had this book I have found several 20 year old GM cars and trucks that never had there chip updated with problems fixed. If your doing a conversion of anykind and you start with a chip that has issues, you will never work them out. Start with a verified latest and last chip offered by GM.
     
  13. JeepsAndGuns

    JeepsAndGuns Farmall Cub

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    That sounds like a very nice book to have. Only problem I see, is actually finding the bin once you know what one you want/need. I'm sure there are lots out there on the net, but I doubt there is all of them.
     
  14. EagleMark

    EagleMark Banned

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    Right around 600 differant bin files in the link in my signature that the DIY EFI community have collected and shared. FREE! :punk:

    Moates website also has a download section with a lot as well.

    As the FAQ here outlines get one as close to your applacation. So starter bin files should not be an issue. But when doing a conversion on a motor that never had EFI will always need fine tuning. Stock engines should start and run fine with a correctly matched bin to start. HTH!
     
  15. JeepsAndGuns

    JeepsAndGuns Farmall Cub

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    While strolling through the local pull a part looking for random items and parts, I stumbled across a 95 gmc sanoma with a 4.3 tbi. Took a closer look and the harness had already been hacked on, otherwise I was gonna grab it. So I checked for the pcm and it was still there. It was a 16194727, so since they are pretty cheap there, I went ahead and picked it up.
    Well I was bored today and just decided to pull the cover off to see if the memcal was the same bcc as the sticker on the outside, and I got a bit of a surprise.

    [​IMG]

    At first I didnt know what I was looking at, I thought I had found something oddball, then I noticed the memcal was on its side and the chip said hypertech. I pull it out and look at it and its basicly the same thing as the moates G1 adapter. The hypertech chip is installed in a dip socket. I removed the chip and tried a 28 pin zif and it fit perfect. So this was a nice little surprise. I basicly got a free adapter.
    The chip is a 28 pin chip, kinda looks like the sticker is covering a window, so I'm guessing its probably a eprom and not a eeprom. If I wanted to read this chip with my autoprom, what chip would I select on the tunerpro moates prom I/O?
    I googled the part number on the chip and it comes up for 94 S-10 trucks 4.3 tbi. And most places I saw it retailed for around $166!

    Another thing I have been wondering, whats the diffrence between the 8625 and the 7427 pcm's? You say they interchange, but I'm sure there has got to be some diffrence.
     
  16. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

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    That's a nice find.
    Differences?
    It's internal and doesn't affect the operation so I never dug into it.
    They work so that's all I cared about.

    You will probably have to peel the label to read the number but my guess would be a 256 chip.
    If your just reading it then just pop it in and try the 128, 256, and 512 chips.
     
  17. JeepsAndGuns

    JeepsAndGuns Farmall Cub

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    Yea I had often wondered what diffrent service numbers ment. I know some are completely diffrent ecm's/pcm's, but on the ones that interchange I didnt know what the diffrence was. So its just the hardware inside them? newer parts, possiably better or upgraded who haas what whatnots that are sodered to the motherboard mabey?

    Yea I just want to read the chip, not try and re burn it and reuse it, I have plenty of the 27SF512 chips for that. I downloaded a defination for that pcm from tunerpro and was just wanting a bin to open with it and just look at all the diffrences between what you can change on the pcm's Vs. the ecm's. I am still a long way away from from attempting a pcm swap, but its nice to just look at it and get an idea of what all is involved.
     
  18. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

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    You may want to download that hypertech chip then do a compare with a stock 4.3 tbi chip and see what was really adjusted.
    From the ones I did, it was very little.

    Or download it and send it to me and I'll do it.
     
  19. JeepsAndGuns

    JeepsAndGuns Farmall Cub

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    Well I tried reading the chip. I tried 128, 256, and 512, I was using the autoprom and I had 0D_TP5_V250.XDF loaded onto tunerpro (yes I have TP version 5)
    each time it said it read it just fine, but when I loaded it up, everything is 0.
    I peeled off the sticker and its a 27C512 chip. It actually says 27C512-12, if that makes a diffrence. I deleted the other ones I had tried looking at and then tried again with the 27C512 chip selected. It read it fine, then then hit the verify buffer to chip and it was good. I saved it and still everything is 0.
    I hoped on tunerpros website and got the 0E_TP5_V250.XDF and also the E6_TP5_V250.XDF Tried all 3 of those and it all still comes up as 0 for everything I looked at.
    Have I missed something? Some other setting I need to select in order to use the 0D or 0E xdf's?

    Also, I was wondering, what the diffrence between the 0D and 0E xdf's? They are both for the same ECM, just one is listed as for the HD trucks. And if the 8626 and 7427 interchange, how come the 8625 uses a diffrent xdf?
    xdf's are another thing I dont fully understand. I know thats what tunerpro uses to read the bin file/code, but why are they so many? I could understand diffrent ones being needed for diffrent ecm's as they get upgraded over the years and new, more, and diffrent features are added to the ecm's. But diffrent xdf's for the same pcm I dont understand.
     
  20. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

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    You shouldn't need any xdf or adx loaded to read chips.
    That is under tools and probably the moates IO or the autoprom selection. Then it just open the flash and burn software, at least on mine.

    If you select the 27c512 and read(with notch toward handle) then use save buffer to file.
    Make sure you know the name and location.
    You can also select edit buffer just to see if all is 0000 or FFFF.
    Probably half will be.
    Post it up (have to send to a compressed file first) or email it to me.



    GM writes the definitions. Each one needs a separate XDF/ADX file.
    The 0D uses the 4l60e trans and the 0E uses the 4l80e trans.
    Different coding to run them.
    So you need to pick the code and the wiring based on the trans you want to run.

    Keep in mind that a PCM is a powertrain control not an ECM- engine control.
    Were talking the whole vehicle now not just the engine.
     

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