So I swapped my engine for a D17A and I am running it on my stock LX ECU so the VTEC solenoid wire isn't connected. I am planning to get an 04-05 EX EM2 AT ECU in a few days.

So I was wondering what kind of issues will I run into after replacing the ECU?

As of now, the only problem is that the VTEC solenoid is unplugged..

One thing that I do know for sure is that I will have to go get the ECU re-flashed after its been swapped.

Anything I should be aware of? Thanks all!!

 

Yes, you have to get the the immobilizer programmed to the ECM/PCM

Just to be clear, you have an LX with a D17A1 (non-VTEC) that you swapped a D17A2 (VTEC) from an EX into?

If that's the case then you're gonna need an EX wire harness (engine and ECM/PCM harness).

Since you didn't mention it I'm assuming you have an EGR, which only came in the 2004-2005 LX.

*All that being said, I think you're going to be really disappointed with the VTEC in the D17A2. If you even notice the VTEC when it kicks in you won't notice very much of a difference. I would just stick with what you have. Good luck.

 

I think there's a difference in the transmission as well......correct me if I'm wrong.

 

A very slight difference in gearing.

 

So will the ecu through a cel code, thats what I'm getting at.

 

I swapped out my old D17A1 (Non-VTEC) for a D17A JDM (VTEC)
Right now, I am running on an Auto Tranny LX ECU.

Will that change what you wrote now that I elaborated?

 

Guys, where can I find the ECU wiring harness? I was able to find the ECU itself but not the wiring.
Link me if possible? >_<

 

The EX ECU will throw a code if the VTEC isn't plugged in.

No, you should be fine as long as you get the immobilizer and ECU synched and the VTEC plugged in.

Nationwide salvage listings: Car-Part.com--Used Auto Parts Market Make sure to ask them to double check that it's the specific harness you're wanting.

Nationwide craigslist search engine: Ad Hunt'r - Search ALL of Craigslist? and more!

Cheapest salvage parts in the land if one is near: Pick-n-Pull » Check Inventory

 

So transmission wise its not gonna shift funny, shift late or throw a code for anything transmission related? Damn thats better than the issue that the 96-00 has.

 

Okay thank you Lazlong!
Im planning to do all this very soon. Ill post pictures of the results

Just another concern… My friend says that I can use MY cars wire harness for the new ECU but I need to go to the junk yard, obtain another wire harness from an EM2, then get one wire from it and pin it into MY wiring harness and run the cable to the VTEC solenoid.

Is this correct?

 

Also,

I am confused about the ECU part number from the EX 04-05 Civic EM2.

Which one is it?
#37820-PLR-A75
#37820-PLR-A73
#37820-PLR-A72

 

It shouldn't throw any codes.

I seem to remember a thread with that topic but, I can't find it. Try here: https://honda-tech.com/honda-civic-2...sting-2101211/ for threads related to this topic. Or try here: Honda Civic Forum Maybe you can find a thread on it.

According to the online parts catalog A75 supersedes A72-A74.

 

So I can get any ECU as long as its:

A72
A73
A74
and
A75
???????

 

As stated, A75 supercedes A72-A74. Technically yes...

 

OKAY guys, I need the ECU pinout for an Automatic 04-05 Civic EX.

Been searching and can't find one. Thanks guys!!

 

While I wait for my ECU to be shipped, I went to the junkyard and got these after searching for hours!


AND…

 

I have 2003 honda LX swapped too a D17a I can't get it to start, it showing the oil pressure light and doesn't sound like the fuel pumped turns on, I have the ecu for the D17a. Please someone let me know I'm at my end.