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D15B VTEC - 3 stage wiring

Discussion in 'ECU's, Electronics, and Tuning' started by vtecjdm, Jul 26, 2005.

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  1. vtecjdm

    vtecjdm Senior Member


    So assuming a couple of you know that a 3 stage D15B vtec exists :p ... do you have any idea how the 2 vtec solenoids are connected to the ecu ??

    Usually there`s only 1 solenoid and so only 1 connection on the ecu. So how do they work ? and which ecu do they use ?
    I dont think a normal p08 ecu will do the job.

    Any info or comments are much appreciated, keep up the good work here ;)
  2. Punisher

    Punisher Member

    P08 is for dual stage VTEC and can't do the job.

    Either the P2J or (P7J)? will. I think the P7J is 4-plug (can anyone confirm?) Both ecus are OBD2.

    Looking at the 3-stage VTEC solenoid, below the spool valves are a strand of wire coming out from each. One of the spool valve has a red wire and the other spool valve has a green/yellow wire like your normal solenoid. Red is for the second stage which I think is wired to A21. Green/Yellow is for the third stage hi duratn/lift cam profile which is wired to A04.
  3. vtecjdm

    vtecjdm Senior Member

    Wow Punisher you seem well informed on the 3 stage vtec.
    Basically many here work only around B 16 B18 and prelude engines so its nice to know that there is someone knowledgable for a small jdm d15b :)

    I asked this question because my car has had that 3 stage engine, but then it got swapped for a normal D15B vtec-e though !... Indeed my current ecu is a P2J - now as far as i`m concerned the only thing i can spot of a vtec-e on my current engine is simplY the vtec-e valve cover.

    Eveything else looks like a normal d15b vtec.
    Anything i should look for ?

    Btw, my vtec enters around 3000 ... checked out some wiring in the engine bay and found out a red wire side by side the green/yellow wire connected to nothing.
    So i was thinking ... is it wired correctly after the swap ? :huh:

    Btw: are you sure about the A04 being the vtec solenoid for stage 3 ? Isnt A04 injector no 4 ?
  4. Punisher

    Punisher Member

    Opps... its supposed to be A08, A04 is for OBD1 VTEC Solenoid.

    Besides the VTEC-E cover, the intake manifold is also much smaller; the dashpot looks more like a runner to me. Why did you swap out the 3-stage VTEC engine? Lack of spares? Or is it beyond repair?

    If you swapped to D15 VTEC-E, the VTEC solenoid green/yellow wire is supposed to go to A21 on the P2J, which means you should connect your current VTEC solenoid spool valve plug to the red wire spool valve engine harness plug.

    However, wouldn't your check engine light light up using the P2J as it will detect a missing connection for one of the VTEC spool valves?
  5. vtecjdm

    vtecjdm Senior Member

    Well, it actually got swapped in japan.
    My current civic had a 3 stage vtec for sure, but i guess something went wrong with it and they just installed a vtec-e.

    What is the dashpot btw ? ..heh er .. well the intake manifold i got is well (quite big actually) and looks exactly like a normal d15b vtec. If i got it right the 3 stage vtec has a small intake manifold .. kinda round .. am i right ? like this ?


    Well mine is not like that at all.
    In my opinion the only thing i got of a vtec-e is simply and only a cover :) believe me, compared to my fellow cars vtec engines (the d15b vtec) .. we both have the same power output - tried and tested ;)
    Thats why i`m kinda confused about the vtec-e cover.

    About the VTEC solenoid spool valve (excuse my ignorance) but where is it located ? .. isnt it the same thing: vtec solenoid - vtec spool valve ?

    Indeed ecu throws engine check lights, but for Crankshaft Sensor and some other obd2 stuff since engine is obd1 here as far as i know.
    And also, unfort. even though i got an ECONO light, it does not work with this engine it seems .. dont think there`s anyway it will ... or ?

    Btw, thanks alot for your help punisher! :worthy:

    Looking forward to any other info which may help.
  6. Punisher

    Punisher Member

    They probably used the VTEC-E cover over your P08 cylinder head. You can check your cylinder head code just above the exhaust manifold. The numbers are in the little circles. VTEC-E cylinder head is coded P07. My guess is you have a P08. VTEC and VTEC-E valve covers use the same valve cover gasket, so the valve covers are interchangeable.

    The 3-stage VTEC P2J intake manifold is the same size as the P2P D16Y8 intake manifold. The only difference is the EGR valve provision on the P2J intake manifold. Check the rear of your intake manifold (driver side) for the code, from your description, its probably P08. Alternatively, this code is found on the dashpot just beside the brake booster pipe.

    If you have a P08 head, wire your VTEC spool valve (= VTEC solenoid = VTS) green/yellow wire plug to your engine harness green/yellow wire spool valve plug. For P07, wire the VTEC spool valve green/yellow wire plug to your engine harness red wire spool valve plug.

    Yeah, the OBD2 P2J ecu will throw a missing CKF sensor code since you are using an OBD1 block. Still you should also get a VTS1 or VTS2 chk eng light code with the P08 or P07 head respectively and probably for the missing EGR valve as well.

    Get the P08 or P28 ecu if you have the P08 cylinder head. P08 is better, no need to convert to 4-wire O2. This will get rid of your missing sensor or chk eng light problem.

    The Econo light lights up in the 12-valve mode. It could be using a sort of relay switch when VTS1 & VTS2 are off. With the P08 head, there is no econo mode to enter into.
  7. vtecjdm

    vtecjdm Senior Member

    Phew man thats an awsome amount of info you gave me there :)
    I`ll double check the head, but i think it is a P08 head.

    Indeed because all the obd2 cel codes and all, i wanna change the ecu to a p28.
    And infact i did get myself a p28 with an obd2a to obd1 conversion harness.

    When i plugged it in i got 2 codes: VTP and O2 heater sensor.

    I got rid of the VTP by taping it to the VTS since i got no VTP Sensor on the engine .. and as for the 02 heater, i`ll either chip the ecu to get rid of code or just buy a 4 wire o2.

    All is fine apart that when i tried to rev the car now .. even standstill, it wont go over 5000. I dont think an 02 heater code would do this to the car, but hope i`m wrong cause I really .. reallly hope its not some wire confusion that is making this happen.
    If i remove the p28 and harness and connect the original P2J ecu back, it revs normal.

    What do you suggest ? :huh:

    Hey thanks again, you helped me out big time.
  8. Punisher

    Punisher Member

    Do you mean you added a VTEC oil pressure switch to your current VTS and got rid of the VTP code? I know some VTS do not have a VTP. Was there a bolt in place where the VTP is now?

    Sounds like you should try installing a 4-wire O2 and see how it goes. If a P08 is cheaper, go for it. The P28 can be re-sold at a better value than a used single-wire O2 sensor. You can probably make some money out of this. : )
  9. vtecjdm

    vtecjdm Senior Member

    No, i do not have a VTP sensor on my engine (as you said i have a bolt in place instead) What i did was tap the VTS wire to the VTP to trick the ecu.
    It worked so ...

    You think the 4 wire o2 could be causing that 5000 rev prob ?
    Sounds so strange to me. Oh well ..

    Where i live (not USA) its such a pain in the ass to get something for honda, i mean you can get anything jdm or not, but it will cost you an arm leg and even foot. And no one understands shit about ecus .. i dont think they`d even want to exchange a p28 with a p08 ! .. heh DamN <_<
    I intend to chip the p28 .. i know it`ll cost me more to buy burner and all the rest but i think its worth it on the long run.

    If after chipping the p28 and still getting this rev prob, i think i`ll simply start smashing my head to the wall.
  10. Punisher

    Punisher Member

    I can only guess 3 possibilities, O2 sensor, tricked VTS and ECU.

    The market prices of ecus can fluctuate like crazy but no matter what, are considered cheap used on the market. New ecus from the dealers easily go for a gran, even the dpfi ecus. I know of a rich guy from some backward country who paid his local dealer this amount for it, he has no internet connection or computer experience whatsoever. He would probably be smashing his head harder to the wall if he ever got one later and found out. : )
  11. vtecjdm

    vtecjdm Senior Member

    Yeah i know what you mean :)

    Btw.. i couldnt believe my eyes, i checked my engine and found out that it IS a P07 ! (cylinder head and intake manifold) .. I couldnt believe my eyes because i tested out the car several times with some normal d15b vtecs around here and we all agreed we both have the same power output... strange.. could it be the tranny maybe ?

    Anyway ..so, to cut this topic short :D refering to what u told me :

    ''If you swapped to D15 VTEC-E, the VTEC solenoid green/yellow wire is supposed to go to A21 on the P2J, which means you should connect your current VTEC solenoid spool valve plug to the red wire spool valve engine harness plug''

    Do you mean i have to short the red and green/yellow wire together or just connect the red wire to the solenoid and forget about the green/yellow wire? Note that i only got ONE solenoid and not two like the 3 stage, could you please re-explain.

    Regarding cels i got code 54 crankshaft fluctuation sensor and code 38 .. what IS a code 38 and how do i get rid of it ? Cant find anythin on a 38 on the net !@

    So hopefully when fixing the codes and solenoid wires correctly the econo light `should` work again, we`ll see.
    Although to be sincere i still do not understand how does a vtec-e engine work.
    I understood everything about the 3 stage, but no one goes into detail on the vtec-e ..how many stages does it have ?

    Thanks once again for your patience man.
    Dont want to get you on your nerves with all the Q's .. thanks :worthy:
  12. drpenguin

    drpenguin Senior Member

    has three stages hommie. goto the temple of vtec. Everything you wanted to ever know about vtec http://www.vtec.net/
  13. vtecjdm

    vtecjdm Senior Member

    Punisher my engine looks just like this:


    Only diff is i dont have the green vtp sensor.

    Drpenguin been there already checked that .. there is no technical description of what a vtec-e does, apart that e is for economy, the 3 stage vtec has 3 stages .. the normal vtec has 2 .. but what about the vtec-e ?
    From what i understood the vtec solenoid in this engine is ONLY used to switch from 12 valve to 16 valve .. about the cam shafts, i have no idea :blink:
  14. Punisher

    Punisher Member

    Hi vtecjdm, been out these few days running around repairing my ride. Only got back today to answer all your Qns. You can read my topic in the suspension segment.

    VTEC-E is also considered 2 stages. 1st stage 12-valve mode and 2nd stage 16-valve mode. The difference between the VTEC-E and normal VTEC are that there no higher profile/duration cam lobes on the VTEC-E camshaft.

    Regarding your first question on 31 Jul. Yes, if you are still using the P2J ecu and have a P07 cylinder head, you should short your current VTS spool valve green/yellow wire with your engine harness VTS red wire and leave the engine harness VTS green/yellow wire alone. (Your engine harness for the previous 3-stage D15B engine has one red and one green/yellow wire for the 3-stage VTS.) Simply the red wire goes into the P2J to activate the 12-valve to 16-valve mode, similarly the green/yellow wire goes into the P2J to activate the wild cam lobes, which is commonly termed VTEC.

    One thing I don't understand is the 3-stage VTS also does not have oil pressure switches (yes, there are two bolts in place of it), so you should not have a VTP code using the P2J ecu.

    Code 38 is probably because the P2J ecu is missing a connection from the engine harness VTS red wire. You will probably solve code 38 but will get code 21 by switching the wires as mentioned in the 3rd para. "Still back to square one."

    With a VTEC-E, you should get the P07 ecu for proper operation. They should be relatively affordable compared to P08s and P28s.
  15. vtecjdm

    vtecjdm Senior Member

    Hey punisher ! No prob mate i had already read your topic .. sucks man :eek:

    Thanks for the info. Got everything sorted in my mind now, well see ... but as you said .. its back to square one.
    Damn, the p28 didnt seem to gimme so much probs. I have fixed the vtp thing and was about to fix the 4 wire o2 sensor thing sinse mine is 1 wire.

    Only prob : I`m not sure that by eleiminating these codes, the engine will rev normally (ie: over 5000) with no probs. This reving thing is gonna get on my nerves ! hmm .. maybe somethin`s not wired correctly ? :blink: i donnooo

    Ay, about the knuckles thing .. r the ek and eg the same ? I got my right one slightly (very slightly) bent but i wish i could change it sometime. Hell they cost here almost as new.. :angry: Damn again
  16. coldtotouch

    coldtotouch Junior Member

    back from the dead...

    Sorry guys, for bringing this back from the dead but i'm interested in swapping a 3 Stage Vtec D15B into my 91 CRX SI really soon... and i'm curious if anyone knows the wiring for the econolight?
  17. kakaroto_ss4

    kakaroto_ss4 New Member


    Can i swap a zc intake manifold on a d15b vtec what i need? and its gonna be better?
  18. whudupfoo

    whudupfoo JDM EK

    hey, i just swaped out my y8 for a d15b. i was wondering if it was ok to hook up only the vtec silenoid and not the vtec-e. would it still work? also, my motor wont seem to idle stedy, any ideas why? id really appreciate any input. thanks.
  19. Victorchew99

    Victorchew99 Junior Member

    it will work depending on situation.

    if u use the hx ecu, either the vtec-e or the normal vtec will work. i'm not sure how the vtec wiring goes on the hx ecu, but i think if u use the hx ecu on the 3 stage engine, it will engage the vtec rather the vtec-e.

    if u use the obd1 ecu for vtec d15b, i think u may have to look into component compatibility i.e dizzy etc.

    whichever way will work, but it takes time to get it right
  20. ej-8[eS]spin

    ej-8[eS]spin New Member

    yo im new to this and i really dont know to much about cars and all that yes im a noob...but anyways i blew my d16v on my civic and i got a d15b"the jdm 1" and having issues with all the wiring ...can any one help my dumbass out???thanks
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