How To Rewire VTEC In Your Honda/Acura

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Ok, assuming you have a vtec motor in a non vtec car and you need to wire in VTEC! here it is…

Our demonstrator model is a 95 CX with a OBD I B16A. So you have your motor in the car, and you are using XXXX engine harness, as long as you have the plugs (usually come with motors harness, even JDM, just remove the whole thing from sensor/solenoid, to canon plug from the harness)) you’re good. First you need to run the wires…

BLU/BLK and GRN/YEL from here…

howtorewirevtec1

To the canon plugs (shock tower connectors)…

howtorewirevtec2

Now, if you are using the vtec harness there’s no need to remove them as there should be nothing plugged into the connector on the other side (on a vtec car, such as a VX, or 92-93, this part is over, as it will have them already) the wires should match up to empty slots. But if there is something on the other side, simply remove them (vtec wires) to an empty slot with nothing on the otherside. For the cabin side of the canon plug, you need to get the pin from the canon plug, to the ECU (junkyard). you need to get enough pins from a junker to connect whatever you are connecting.

Anyway now you have the wires going from the vtec solenoid, to the canon plug and out the other side (note, I have both YEL/BLK, be smart and use different colors so you don’t have to guess which is which at the ECU)…

howtorewirevtec3

Now, make sure the wire coming out of the cabin side of the canon plugs is long enough to go through the firewall, and to the ECU.

For the ECU connections same as the canon plugs, you need to acquire the pins. You can pull these out of a junker also. All the pins from the same generation are the same (there are two different sizes in each plug, you’ll be using the smaller ones), and I was told that they are all the same from any model, and probably all generations, but I won’t swear to it.

Here’s how to remove the pins from the ECU…

*** picture coming soon ***

If you want to take the time, you can pull the wire al the way from the ECU plug, to the canon plug, but I just splice a couple together, it saves a lot of time.

Here is what you should have…

howtorewirevtec4

The ECU slots on the non vtec models should have nothing in place, just a hole. At this point you should know where the pins go BLU/BLK (in the engine harness, maybe different if you used a different color wire) to D6, GRN/YEL (same as the other) to A4, so what are you waiting for, plug them in already…

howtorewirevtec5

Any time you need to splice wires together, I suggest soldering them when done, if you can’t, at least use a good male/female plug, I like these… (soldering your wires…no, really, do it)

howtorewirevtec6

Now, you should have vtec y0!, drive around let your car warm up and then let it rip (provided you aren’t still throwing a CEL code). If everything is kosher, bolt in your ECU, wrap everything up, and blend it into your harness for that nice clean look.

You can also by pass the canon plug, and run a hardwire all the way from sensor to ECU, this works to, but doesn’t look as clean.

Here is some more wiring pics, to give you some ideas. In the first one, I am using a VX harness (5 wire o2) on a B16A (four wire o2) in a CX (1 wire o2) so I had some issues . Anyway, after figuring out what wires were what, I used my handy connectors and connected…

howtorewirevtec7

For the switched 12V, I used the plug full of YEL/BLKs on the driver side, that goes to the main relay (thanks Poison), and spliced into one of the wires, then ran it to the o2 taping it into the harness once it was all connected, running right…

howtorewirevtec8

If anyone found a mistake, or has something to add feel free. I hope this can help someone that like me isn’t real confident in their wiring abilities. All in all you are only limited by how much work you want to do. You can go for a quick get it going job, or undo your whole harness and rebuild it better than OEM.

A funny antidote that happened during this, so, my car even though it was a CX had a VX motor in it, so it was wired for vtec, sort of. Anyway there was no vtec kicking in, and I was throwing CEL 21, so I looked, and realized the guy that had swapped in the VX motor, had mix up the vtec wires, so I unplugged the canon plug and made sure what was where, and undid the wires, and switch the two of them right. Well, I get in the car and go to start it, and it’s cranking, but nothing, like it has no fuel. So I was like “fuck” pull the codes. I get 6, 15, 21, 41, so I am thinking that switching the wires really screwed something up, so I go and re wire them like they were, and am looking at it, and then realize, duh, I didn’t plug the canon plug back in :P , So I plug it in and get no codes, I was right, they were backwards, so I went for a cruise to make sure all CELs were gone, hammered it, and all is good.

Information Source: http://hondaswap.com/general-tech-articles/how-wire-vtec-40811/

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About Author

Hans Desjarlais is an import car enthusiast and entrepreneur who loves all things that look good and go fast. He is editor-in-chief at Import Insider and after selling his JDM engine import company in 2008, decided to offer advice and tips to people in the import car industry. As an insider he can tell you what to look for and what to avoid. Keep in touch with him on Facebook and follow him on Twitter.

47 Comments

  1. hey i have an important question.
    i have a 95 accord lx it doesnt come with vtec..but i did the swap to a h22a4 dat came off a 2000 prelude. the engine starts and everythin now the problem is wher do i connect the vtec since i have my stock ecu?
    do i do the same as u did here or does a change alot? or do i need the ecu from the 2000 prelude?? thanks

  2. hey, do we just cut those 2 yel/blk wire for the vtec and pressure switch.do we even need those yel/blk wires.can u send me a picture how it look like after u finish from the canon plug.

  3. hi am trye to buy k20 , but my fryends tell me then h22 is betther but , i whant the more hp and trq , much i cant so what did you recomend me????????????

  4. If you’re going from a non vtec to a vtec you need to swap out the ecu and the wiring harness as well…. when purchasing the ecu and wiring harness make sure you get them from the same trasnmission type and your car.. so if you have a manual transmission you need to get an ecu and wiring harness off a manual transmission prelude

  5. im trying to do a swap to my 90 integra ls do you think that i could do a jdm 93-95 gsr or is it better to do b16a thanks.

  6. I’ve a 1999 honda prelude i just change the engine because the original one got overheated is a h22! ok so i bought a japenese engine they look the same they toll me that i just need to change the “knock sensor” from my old motor to the one i just bought but the thing is that i can’t install the sensor is blank there no where to plug it do you know why?s

  7. i have a 97 4 dr civic i want to put a v-tech with close to 200 hp but i dont know what motor will fit in the cheapest?

  8. I have a 1993 honda civic ex the engine is 1.6L I ordered an engine but was sent the wrong engine. Will a 1.5L (D15B) JAPANESE bolt into this car. The valve cover on the 1.5 has v-tec stamped on it and on the packaging they wrote D15Z6. Is it a v-tec and is $925 to much for it? It supposedly only has 36,000 miles on it. BAYOU AUTO PARTS says it will work and if I need anything to make it work they will provide it.SHOULD I START THE SWAP OR DEMAND MY MONEY BACK?????

  9. i have a 2001 honda accord EX and the inside of the muffler has alot of back carbon built up what seems to be the problem please help

  10. hi so i have a si and want to swap it into a coupe that is stock but has vtec so can i just plug it in and be fine or do i have to rewire?

  11. Hi hans007, I am running a vx engine in my 94 cx how do I wire up my o2 correctly? I am using the vx harness and ecu also. Email chalupa9151@gmail thankyou

  12. ok i have a 93 prelude si with an h22a vtec swap already done an i love it , but now i wanna do another 95 prelude h22 swap for a show car but i want something a bit faster. i know theres h22a h22a1 h22a4 an h22 type s what motor would be the best for more hp an what do i need to do the swap? i didnt do the swap in the one i have now so i dont know what the hell im doing but i wanna do it.lol email me with an info if possible sincere_1278@yahoo.com thanks

  13. Maganda Moses on

    Hi, i have a Honda Integra 1995, i recently bought a Honda V-TEC engine D15B BUT it didnt have its ECU and wiring. Is it possible to get an ECU and wiring for another Honda vehicle e.g Honda CRV and it works? The vehicle is automatic and was formally a carburator system but am changing it to EFI. Is there any information i need to know guys, am stressed by mmy my highly regarded CAR., Moses (Uganda)

  14. so called mechanic switched a 1993 non vtech eng in a prelude manual trans he put a vtec h22a
    in the prelude.car aledgidly runs ok but idles at 3000. he told my buddy to get ecu for h22a vtec which
    he shipped overnight problem not only wasn’t solved but got worse.I am no tech by no means but if you could help me
    point him in a direction we would both appreciate it.Thanks man jimstew3367

    • Hi Jim, sry for the late reply. If you haven’t figured out your problem yet, check these two things.
      1. Make sure the ECU is for a manuel (if it has J50 in the part # anywhere, that is no good.
      2. Check the vacuum lines are properly connected.

    • Hi Javier, sorry for the late reply. If your still looking for the knock sensor use the form on our site and a shop will get back to you.

  15. travise 97 civic d16y8 on

    Dood I have a 97 civic that was a dx body they did the ex motor swap I have a dx wire harness an ex ecu and an ex motor how do I wire the vtec in??

  16. I have a good question i have a 97′ honda civic coupe ,ex edition and i was wondering what would be a great motor to swap the original with? im looking for something that would really make my car fast. i was thinking about an acura engine but im not to sure about which make would be best. Any suggestions?

    • Hi Corie,

      I would go with either the Civic B16A 3rd Gen VTEC engine or the Integra B18C GSR or B18C Type-R engine. If you want to get a quote on these engines go ahead and use the “Get A Quote” form on our site and someone will get back to you with prices.

      Hans

  17. Kayce Peters on

    I am swapping an H22A into my 94 Integra LS. I bought an ECU but need to know how to get it to connect to my wire harness or how to make a jumper wire for it. Also, I am having trouble finding swap mounts for automatic transmission. I bought some but later found out they’re for manual transmission. Do you know where I could find some?

  18. chelsealianne@hotmail.co.uk on

    hi.. i had a ej1.4 p reg civic i then put a b16a2 out of a 1992…; then got a engine loom off a 1996 up.. had to change some of the clips to fit.. ( dizzy and altornator) it will still not run v tec what wire/clip needs to be in v tec or is there sumthing else wrong

  19. This site is dead on correct. I had the same problems and was having a hard time to get things to convert over. I found my sway engine at ASAP Motors locator free service. The guys shipped it to me and I found this exact problem. I have been looking everywhere for the info. Thanks!!

  20. hi..i have a honda accord SV4 single cam, i’m need to know about engine spec of H23A, can i swap it to my car?

  21. i have a 94 cx with b18b1 gsr head ls vtec i have been fight like crazy to get the vtec to work im running po6 ecu on chrome any info is welcom please…..thanks

  22. i have a 93 civic with a non vtec d15 and i just bought a d15 vtec and i kno i need the p28 ecu but what wire harness do i need to switch it without the trouble of cuttin wires an stuff

    • Hello Lucus,

      It would be much easier and cheaper for you to simply rewire the VTEC wires directly from the engine to the ECU. Otherwise you can buy a engine harness from a 92-95 Civic SOHC VTEC 1.6L.

  23. i have a 97 accord that came with the 2.2 non vtec motor. it now has the 2.3 vtec motor from a 98 accord. the problem is the vtec solenoid isnt hooked up, do i just hard wire it into the ECU? (i bought the car like this)

  24. Any chance someone has these instructions for an 02 Civic LX MT which had an EX V-TEC dropped in it, with the EX AT harness? Specifically, how to wire the secondary 02 sensor.

  25. Hi Hans,

    Good day!

    This time is the other way around. Got a honda civic 2003 with a 3 stage vtec (2solenoids) but i had this changed with a single vtec (1 solenoid only) engine from Japan. Both are the same D-series engine though the version that was released in our country have a 3 stage vtec. Japan version is a single vtec only but it has a 1.7l displacement compare to my 1.6l engine. This replacement engine is running fine but i have this engine sensor lighting everytime i i reached 100km/hr on my speedo. I believe it’s the 2nd vtec/solenoid causing this engine light error, my ecu tries to activate the 2nd vtec but it is not functioning, no connection at all. How will i bypass this sensor?

    • Did you get the ECU with the Japanese 1 stage VTEC engine? If, not you’ll need to get it or have your ECU chipped.

  26. No i don’t have it. We used the same elec’l harness and ecu since we only replaced the block and the head. Everything is ok except for this 2nd solenoid connector w/c is left hanging since the jdm head is single solenoid only. i think the ecu is ok i only need to know how will i disable the switch.

  27. my honda 94 model wouldnt start after it got burnt and i replace the complete engine wire, change the ignition and some other thing it s just rolling but dont shock

    • Hello Jun,

      Any import performance shop in your area should know how to do that. There are also guides online which explain how to do it in case they don’t. Don’t go to a dealer though, they usually never want to do things like that.

  28. reggie tapia on

    Help !!! I recently changed out a 1.7 non vtec on my 2004 honda civic LX for a 1.7 vtec japenese engine. Engine looks great I get a engine light for a bad camsensor when I drive on highway I have no problems until I floored it then the car stalls and won’t go over 3 rpms. Car will drive fast over 60 mph but when I floor it it stalls is the problem as simple as changing cam sensor or change out computer or what

    • Hans Desjarlais on

      Hi Reggie, it sounds to me like a computer problem. Is your car Auto or Manuel? Make sure you have the right computer for your engine and trans. Going along past experience, 95% of the time that issue was related to the wrong/defective computer.

  29. José García on

    I have Honda prelude 93 Non vtec engine 2.3 automatic trany.
    This engine get overheated. So
    I buy another engine When talk to the person. Told me that 2.2 a4 was the same so replace the engine but now the car wont start Use the same wire harness sensors are on the same position Know this engine come from 93 prelude. Standard trany. Please reply appreciated your time.

    • Hans Desjarlais on

      Hola José, this could be due to several reasons, unfortunately I am not a mechanic so I would recommend you have a professional mechanic or tuning shop have a look. The fact that it doesn’t start isn’t related to VTEC. I would double check to make sure the engine was properly installed and connected.

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