1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

ISNT Auto&Manual EPROM Chip same use for VTEC ecu

Discussion in 'ECU's, Electronics, and Tuning' started by natecspecr, Dec 14, 2004.

  1. natecspecr

    natecspecr Member

    Messages:
    36
    Likes Received:
    0
    Joined:
    Dec 13, 2004
    Hi need help/explaination on this doubt .
    Isnt the Auto and Manual EPROM Racing Chip M27C256 can be use(interchange)o each others
    ECu for B16A VTEC DOHC ecu P30-3820-000?
    Actually what does this EPROM chip M27C256-12FI , the12FItan for what ? isnt speed ?
    Then the higher the better ? if just using M27C256 only, how?
     
  2. cycloneb18c3

    cycloneb18c3 Senior Member

    Messages:
    1,056
    Likes Received:
    0
    Joined:
    Aug 10, 2003
    Location:
    New Jersey
    wow, I dont think anyone on here will know this one...
    best to post it in the ecu/electronics section also
     
  3. pills_PMD

    pills_PMD Super Moderator

    Messages:
    4,232
    Likes Received:
    0
    Joined:
    Sep 30, 2002
    Location:
    New Albany, OH
    :pillmove:

    moved to ecu's.
     
  4. pills_PMD

    pills_PMD Super Moderator

    Messages:
    4,232
    Likes Received:
    0
    Joined:
    Sep 30, 2002
    Location:
    New Albany, OH
    it's tough to sift through the wording.. but what i think you asked was this:

    "can an auto or manual program be burned onto 27c256 chips?"
    answer: yes.

    or maybe it was "are 29c256 chips better than 27c256?"

    answer: 29c256 can be reprogrammed...

    if i missed the boat on this completely please try to rephrase it
     
  5. projekteg

    projekteg Senior Member

    Messages:
    311
    Likes Received:
    0
    Joined:
    Oct 25, 2004
    yes, the '12fi' represents the speed of the chip (12ns), the shape (f), and the grade (i = industrial). you need 70pc, 90pc, 70pi, or 90pi. to answer your original question, yes, you use the same chip for an auto or manual, the only difference actually lies in the factory hardware in the ecu.
     
  6. CRX-YEM

    CRX-YEM Super Moderator Moderator VIP

    Messages:
    4,623
    Likes Received:
    54
    Joined:
    Sep 29, 2002
    Location:
    Wallingford, CT



    Close, but both the 27c256 and the 29c256 can be reprogrammed.
    the 29c256 and 27c256 both share the same pinout they can be used interchangeably

    The difference is the 27c256 is an eprom, uv eraseable which takes a while.
    and the 29c256 is an eeprom, electrically eraseable.

    and the numbers after the Dash are the speed in nanoseconds, and the lower the number the better.

    e.g.
    29c256-120 = 120nanospeconds
    29c256-70 = 70 nanoseconds

    the 70 nanosecond is faster, and I think the spec for honda ecu's is anything faster tha 110 nanoseconds.
     
  7. projekteg

    projekteg Senior Member

    Messages:
    311
    Likes Received:
    0
    Joined:
    Oct 25, 2004
    i would go no slower than 90ns
     
  8. nfn15037

    nfn15037 Senior Member

    Messages:
    670
    Likes Received:
    0
    Joined:
    Mar 1, 2004
    Well technically, an auto .bin wil have code in it for the lockup solenoid, whereas a manual .bin wll not have that code.
     
  9. AllMotorMonster

    AllMotorMonster Senior Member

    Messages:
    542
    Likes Received:
    0
    Joined:
    Oct 13, 2002
    Location:
    Inland Empire foo!
    Need to clear something up.

    12FI
    70BI
    90

    They all mean simiar things....

    However, 12FI is a 120 nanosecond access time chip.
    70BI could be a 700 nanosecond access time chip.

    You need to check with the manufacturer of the chip to understand their coding.

    Honda's factory (external rom) is 150ns access time. I've used 200ns chips successfully.
     
  10. pills_PMD

    pills_PMD Super Moderator

    Messages:
    4,232
    Likes Received:
    0
    Joined:
    Sep 30, 2002
    Location:
    New Albany, OH
    thanks for the correction.. .i've been out of playing with the hondata for a while now thanks to the s2000.. amazing how fast you forget shit.
     
  11. natecspecr

    natecspecr Member

    Messages:
    36
    Likes Received:
    0
    Joined:
    Dec 13, 2004

    This is what i mean . So thank you for your explaination . How you know the honda`s factory setting for external EProm is 150ns ( 15FI) right ?
    And if i got one racing chip can i use for auto ecu and manual ecu b16a ? isnt the same >? got difference between this ?
     
  12. projekteg

    projekteg Senior Member

    Messages:
    311
    Likes Received:
    0
    Joined:
    Oct 25, 2004



    yes, you could used the same chip in an auto and manual ecu. the only differenc lies in the actual ecu at rp17, rp18, ic15, and ic16, not in the actual rom.
     
  13. b204dr

    b204dr Senior Member

    Messages:
    915
    Likes Received:
    0
    Joined:
    Oct 11, 2004
    Location:
    Minnesota
    this is all mumbo jumbo to me !
     
  14. projekteg

    projekteg Senior Member

    Messages:
    311
    Likes Received:
    0
    Joined:
    Oct 25, 2004



    i don't think the chips actually contain code for the lock up solenoid, i believe it's dependent upon resistors in the circuitry for the lock up solenoid, could be wrong, but as long as i've chipped/programmed ecu's, i've never heard anything about lock up solenoid being coded in to the chip, and i'm pretty sure as long as rp17,rp18, ic15, and ic16 were untouched on the board, you could successfully run any .bin for that engine with auto tranny.
     
  15. nfn15037

    nfn15037 Senior Member

    Messages:
    670
    Likes Received:
    0
    Joined:
    Mar 1, 2004
    Huh interesting....I was under the impression that there needed to be some sort of output from the MCU(obvously the extra SK5151s convert that from a low level to a useable 12V signal). Last time I disassembled an auto .bin it had a bunch of labels etc that I had never seen before in a manual .bin. Have you ever compared an auto p28 bin to a manual p28 bin in a hex editor? Maybe it is just subtle map differences but I always assumed it was code....*shrug* lol not like any of us run auto trannies hehe.

    nfn who likes to split hairs.... :D
     
  16. AllMotorMonster

    AllMotorMonster Senior Member

    Messages:
    542
    Likes Received:
    0
    Joined:
    Oct 13, 2002
    Location:
    Inland Empire foo!


    Because the factory "Optional" eprom is made by "Oki"

    The part number is "M27256-17"

    17 designating 170ns access time.

    BTW, you will sometimes find these in P05, P06, P07, P08, P28, P29, P30, P74, P75, PR4, P72, P90's and a host of others. They are a standard 28pin eprom with a beauty copper-gold sticker covering the UV hole.

    Like this:
    [​IMG]
     
  17. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

    Messages:
    28,465
    Likes Received:
    228
    Joined:
    Sep 30, 2002
    Location:
    Dallas / Fort Worth, TX


    Because AJ knows his ECUs. :thumbsup:
     
Verification:
Draft saved Draft deleted

Share This Page