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P54 ECU - Difference between auto & m/t version?

Discussion in 'ECU's, Electronics, and Tuning' started by CQB18B, Sep 30, 2016.

  1. CQB18B

    CQB18B New Member

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    A couple years ago I bought a 1996 Civic DX (6th Gen) with a JDM B18B non-vtec that looks to be maybe 1994-ish, and an SC4, 5-speed trans. I've been using it as a daily driver and it's been doing well in what appears to be a basically stock configuration. The ECU it came with is 37820-P54-900, which based on my research is for a Honda Domani (Accord?) with an automatic trans.

    My question is... what, if anything, would be different between the P54-900 ECU for an auto trans and a P54-000 or P54-J00 ECU for an manual trans? Would there be any benefit to switching from the auto ECU to the manual ECU?

    It may be obvious by my question but I'm new to this but very interested in the options available with this engine swap.

    thanks in advance for any help/input you have.
     
  2. CAFROG

    CAFROG Honda Minion VIP

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    I did not think one could run an auto ecu with a manual trans. I'm stumped if your ecu is an auto.
     
  3. CQB18B

    CQB18B New Member

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    Apparently it can, P54-900 ECU.jpg I've got no reason the think the ECU is anything other than what the tag indicates and based on the info found here http://hondaswap.com/threads/honda-ecu-list.29129/
     
  4. CAFROG

    CAFROG Honda Minion VIP

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    If it was chipped, it would not be seen in your picture. That's the only way I can see it working.

    Google pic:
    https://goo.gl/images/WaWprp
     
  5. CQB18B

    CQB18B New Member

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    here's a pic of the whole ECU, is it "chipped" ? And if it is chipped would that mean that a m/t (000 or J00) version would work equally well? P54-900 ECU Whole.jpg
     
  6. CAFROG

    CAFROG Honda Minion VIP

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    I'm far from an expert but that chip with the orange spot (bottom right) is the location a chip would be. Can guys program an auto to be stick with a chip? I don't know but it seems like the only logical explanation.

    A P75 is the popular ECU for your motor
     
  7. CQB18B

    CQB18B New Member

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  8. CQB18B

    CQB18B New Member

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    Yeah, I've noticed that the P75 is frequently mentioned in relation to the motor I have. I guess I'm just a little gun-shy about paying for a different ECU model than what's there even though it appears the one I have is already modified.

    The issue I've got with this one is that two of the components (two big round items in the upper-left quad of the last pic) of this board cooked last week. The car died but restarted and has run "fine" since. I can't help but think that continuing to use this ECU is a ticking time bomb for something else to go wrong and I'd like to replace it.
     
  9. CAFROG

    CAFROG Honda Minion VIP

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    Your chassis and wiring is OBD2A. What is the OBD of the ECU? I'd get the same OBD as the ECU but a P75
     
  10. CQB18B

    CQB18B New Member

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    Based on your threads you've been through some of this stuff, that 92 Si is sweet looking. Do you have experience with a source for ECUs that you'd recommend. I've got a little to spend but not a lot and I've been looking around on Ebay.
     
  11. dilbeckskate

    dilbeckskate infamous

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    IIRC there is no difference in maps between manual and auto , if obd1 or 2 would be throwing auto trans codes , if you want to make power have the ecu socketed and go get a pro tune
     
  12. CAFROG

    CAFROG Honda Minion VIP

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    If the ECU is toast then I'd find one.....But manual

    Redline Honda Dismantler/Recycler in Rancho Cordova, CA is a place I trust. I've bought many things from them. I also like hmotorsonline.com I bought my K20R swap from them. Great service.
     
  13. Xanatos

    Xanatos Village Idiot VIP

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    This is one the best newbie posts I've ever seen holy crap. Props to CQB18b.

    Back on topic I agree with everyone that has posted prior. I'd snag a OBD2 (96+) Integra RS/LS/GS 5 speed ECU (P75) and run that. I usually get my stuff from junk yards (car-part.com is a good site to look at listings in my experience).
     
  14. CQB18B

    CQB18B New Member

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    So I've received and installed a USDM P75-A01 ECU and that seems to be working fine. Thanks for the input, now I just have to figure out how to nicely fit this USDM unit in the space that seems more suited for the P54 JDM ECU size
     
  15. Xanatos

    Xanatos Village Idiot VIP

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    If you get one hole lined up and torque it down tight it should hold.
     
  16. CAFROG

    CAFROG Honda Minion VIP

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    Glad things are running well. The USDM ECU will fit. Those JDM ECU's are tiny. Take a few panels off to get the carpet back enough and you'll see a way to mount it.
     
  17. CQB18B

    CQB18B New Member

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    A follow up on this topic, does anyone know if the small differences in the HP and torque specs between the JDM B18B and the USDM B18B1(?) are influenced at all by whether the ECU is a JDM ECU or a USDM ECU? I understand that the engine compression ratio is a matter of physics but some other aspects can/are managed electronically by the ECU and I would think that would influence those specs.

    and again, thanks to you who have given input, being new to this it's good to know there's a place to access pooled experience and knowledge. Hopefully as I get more experience I'll be able to contribute as well
     
    Last edited: Oct 15, 2016
  18. CAFROG

    CAFROG Honda Minion VIP

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    Based on my knowledge.....no differences in ECU's and/or they're inconsequential.
     
  19. CQB18B

    CQB18B New Member

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    The USDM ECU fits in after removing a bracket that appears to be there for the JDM ECU.

    All done with this part of the project for now
     
  20. Xanatos

    Xanatos Village Idiot VIP

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    If you want it to run at peak efficiency I'd get the ecu chipped and tuned, otherwise I think you would be splitting hairs between the usdm and jdm ecus. I have read that the jdm ecus have a more aggressive tune but I have no way to back that up other than hearsay. Does it seem to run any different now?
     
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