K24 Swap ECU and Harness options?

D

dsmithwc04

Daily Driver
I'm currently in the process of swapping in a K24 JDM with K20 head into my X and will be data logging (racecar) with an AiM MXG 1.2 using CAN connections to pickup engine sensors. Currently I have a partial engine harness from the K24 and a full engine management harness from a K20A2 car including the factory ECU (PRB). I don't currently have a solidified plan moving forward and have considered going with Hondata or perhaps even a stand along ECU like FuelTech. I have a few concerns and was hoping to get some input from those who have ventured this direction.

Which factory engine harness is used when running a k20 head on a k24 block? Are there aftermarket options available for this?
Will using the Honda k20 PRB ECU be viable if running Hondata for a k24/k20 setup?
 
The best "bang for buck" option would be a K20A2 wiring harness from an 02-04 RSX type S with a hondata. That harness will have all the connectors you'll need and the hondata is a very capable ECU that is user friendly. Unless you plan on making north of 1000hp the hondata has all the tunability you need. A Rywire harness would be a good upgrade form a longevity and tidiness perspective and they can even custom spec a harness if need be.
 
I used the factory (JDM) 05 TSX harness that came with my drivetrain, swapping to a K20Z3 head didn't change anything. All the K24 sensors fit in the same locations.
 
Thanks for the input! Unfortunately I don't have the full JDM harness but if the k20a2 harness will work then I'm golden since I have a full engine harness and ECU.

I plan on having 4piston work up something special on the k20 head.
 
dsmithwc04 said:
Thanks for the input! Unfortunately I don't have the full JDM harness but if the k20a2 harness will work then I'm golden since I have a full engine harness and ECU.

I plan on having 4piston work up something special on the k20 head.
Click to expand...

I don't know if the K20a2 harness will work with the K24 motor & transaxle. It likely depends on the model year.
 
It is my understanding that the only harness I need is the engine management harness which uses 2 of the 3 ECU plugs. The rest of the harnesses are not viable correct? One of the harnesses includes the OBD2 port and leads into the remaining ECU plug but I don't believe this is at all needed since it appears to control things like HVAC, Radio, etc..

For reference this will be a competition vehicle and not ever driven on the road.

Also, how does the Hondata ECU handle the fact that there will be no keys for this?
The CAN +/- are reachable from inside the ECU correct?
I plan to use a fuel cell and aftermarket fuel pump. Will this cause any issues with the Hondata ECU (does it expect a factory fuel pump circuit?)
 
IMG-6336.jpg


The EMS harness includes connections for the transaxle - VSS at least, can't recall offhand what else. I use KTuner, which disables the immobilizer through software. Hondata I'm not familiar with, perhaps it uses a separate module ?

I don't have any info on accessing CAN Hi/Lo. EDIT - I think CAN data is accessed from the OBDII port?

The fueling you can run via the Honda wiring - I used it to trigger the system relays as with the standard K20 swap wiring layout.

IMG-20191223-172529.jpg
 
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lookforjoe said:
The EMS harness includes connections for the transaxle - VSS at least, can't recall offhand what else. I use KTuner, which disables the immobilizer through software. Hondata I'm not familiar with, perhaps it uses a separate module ?

I don't have any info on accessing CAN Hi/Lo. EDIT - I think CAN data is accessed from the OBDII port?

The fueling you can run via the Honda wiring - I used it to trigger the system relays as with the standard K20 swap wiring layout.
Click to expand...
Thanks for the pics. I'll go ahead and keep all the harnesses for now.

Correct, the CAN is on the OBD port but this should be located inside the ECU at least from what I've seen on Hondata vids on youtube.
 
dsmithwc04 said:
Thanks for the pics. I'll go ahead and keep all the harnesses for now.

Correct, the CAN is on the OBD port but this should be located inside the ECU at least from what I've seen on Hondata vids on youtube.
Click to expand...

The Wiring diagram for the year/model car your harness came from will indicate which pin locations are CAN hi/lo, feeding the OBDII port. I don't have mine handy, I use '05 RSX to go with the ECU I bought.
 
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