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So I have an 03 lx that had a d17a1 non vtec, it blew I swapped to a jdm d17a and sxla jdm trans. Was running the stock ecu and harness for a while but kept having issues with the pcm and transmission. So now I have a jdm ecu and jdm harness along with the ex exhaust. After looking at the harness I noticed there is only one 02 sensor plug. Is this normal? I assume this is for the upstream? Since my ecu will be a jdm harness should I assume it will not look for a 2nd 02 sensor?
I read another forum about people using jdm ecu and it not communicating to the immobilizer. Ever heard of this?
Last edited by BrotatoChip; Oct 24, 2019 at 02:16 PM.
Reason: Edited for read-ability
The LX has both O2 sensor connectors on the engine harness. The EX/JDM has one on the engine harness and one on the engine compartment harness. If you don't wire up the secondary O2 sensor you will get a fault. The below thread describes how to do it.
The LX has both O2 sensor connectors on the engine harness. The EX/JDM has one on the engine harness and one on the engine compartment harness. If you don't wire up the secondary O2 sensor you will get a fault. The below thread describes how to do it.
I don't think a Honda dealer with have any issue with the JDM ECU.
Originally Posted by Swebb
this may be a dumb question but is the engine compartment we harness a different harness then the engine harness?
Yes they're different. The picture below is for an EX. C142 is for the primary O2 sensor, C455 is for the secondary O2 sensor. You can see they're on different harnesses.
Or you can reset the transmission ecu by putting in key turning to position 1 hold gas petal down for 40 seconds then let go of pedal and take out key then put in key and start engine, this puts the transmission on learning mode so it recalibrated itself
I took a ex ecu to them and they tried to say the file is for an 13 civic but the part number for the ecu is an 03
however it took the flash but now when it shifts under hard acceleration is like revs and stutters and then shifts.
I asked them to try the jdm ecu and waiting to see what happens
Originally Posted by Marcelo Souza
Or you can reset the transmission ecu by putting in key turning to position 1 hold gas petal down for 40 seconds then let go of pedal and take out key then put in key and start engine, this puts the transmission on learning mode so it recalibrated itself
after you put it in learning mode it’s finicky for a couple miles then it gets normal
I think you are referring to an idle relearn which is solely for the purpose of learning your idle. And that process was done already anyways when the ecu was flashed
The d17 transmission is weird I have a Truro charged one that’s an auto and I use the gas pedal like it’s a manual. Rev up get off gas then back in the gas slowing to a stop throw it in netrual for some reals on it likes it better
My bad,I didn’t explain myself their is a bolt on the back of where the cables meet the throttle body and you can raise or lower your idle speed from there, I have a bigger camshaft so is would stall out if it idled at normal idle speed that’s why I’m saying that. But yes you are correct
Actually most JDM ECU's have no immobilizer and therefore don't need to be flashed. I'm running one in my Civic right now from a JDM Honda Stream and it runs perfect, no flash required. Just needed to move the fuel pump relay wire down 1 hole on the ECU plug so it starts. What's the part number on your JDM ECU?
actually most jdm ecu's have no immobilizer and therefore don't need to be flashed. I'm running one in my civic right now from a jdm honda stream and it runs perfect, no flash required. Just needed to move the fuel pump relay wire down 1 hole on the ecu plug so it starts. What's the part number on your jdm ecu?
Actually most JDM ECU's have no immobilizer and therefore don't need to be flashed. I'm running one in my Civic right now from a JDM Honda Stream and it runs perfect, no flash required. Just needed to move the fuel pump relay wire down 1 hole on the ECU plug so it starts. What's the part number on your JDM ECU?
How come you has to move the wire?
im running a jdm harness in to a us ecu currently and it fires right up.
so you think I can just put my jdm ecu in the car and it would start right up?
is it accurate that jdm ecu don’t use check engine codes like we do here?
im running a jdm harness in to a us ecu currently and it fires right up.
so you think I can just put my jdm ecu in the car and it would start right up?
is it accurate that jdm ecu don’t use check engine codes like we do here?
That's the ECU that's in my car right now, and yes the engine light and OBD port works the same as the US ECU. On the ECU's chassis plug (the white plug that's atatched to the car's harness rather than the engine's harness), there is an "Immobilizer fuel pump relay" wire, basically to turn on the fuel pump relay so the fuel pump runs. You need to move that yellow/green wire down 1 hole so the fuel pump will run. Here's a diagram, you need to move that wire to the hole in the hole in the plug right above the white/black wire. Other than that it will start right up though. Let me know if you have any more questions https://www.d-series.org/cdn-cgi/ima...5&d=1079124763
That's the ECU that's in my car right now, and yes the engine light and OBD port works the same as the US ECU. On the ECU's chassis plug (the white plug that's atatched to the car's harness rather than the engine's harness), there is an "Immobilizer fuel pump relay" wire, basically to turn on the fuel pump relay so the fuel pump runs. You need to move that yellow/green wire down 1 hole so the fuel pump will run. Here's a diagram, you need to move that wire to the hole in the hole in the plug right above the white/black wire. Other than that it will start right up though. Let me know if you have any more questions https://www.d-series.org/cdn-cgi/ima...5&d=1079124763
i went out and swapped the ecu out and couldn’t get it to turn over. The green key light was flashing when I did so. I didn’t however try your suggestion with the wire.
doesnt the green key mean it’s not recognized the Immobilizer?
i went out and swapped the ecu out and couldn’t get it to turn over. The green key light was flashing when I did so. I didn’t however try your suggestion with the wire.
doesnt the green key mean it’s not recognized the Immobilizer?
The key light will flash with a JDM ECU because the car's immobilizer won't talk to it since it has no immobilizer, but that won't keep it from starting. Mine does the same thing and runs fine, but you can unplug the immobilizer module on the ignition switch and put a stop to it if it bothers you. The reason it's not starting is because the fuel pump isn't running because you didn't move that wire down. Trust me, I have that same ECU
The key light will flash with a JDM ECU because the car's immobilizer won't talk to it, but that won't keep it from starting. Mine does the same thing and runs fine, but you can unplug the immobilizer module on the ignition switch and put a stop to it if it bothers you. The reason it's not starting is because the fuel pump isn't running because you didn't move that wire down. Trust me, I have that same ECU
good look! I’m gonna give it a try. Otherwise I gotta figure out how to trick my ex ecu to not look for the pressure switch.
Let me know how it works and if you need any more help
so I pulled a pin and wire out a junk harness repinned right below the yellow and green wire and then took that wire above and just pushed it in to make contact with the origina yellow and green wire. No start still
I also spliced into the yellow and green wire with a 12 volt constant and still no start.
Do you hear the fuel pump run when you turn the key on? It should run for a couple seconds and shut off. Also, the ECU grounds that wire rather than providing power to activate the fuel pump relay if I remember correctly, but it's been a while so I could be wrong about that. I will check when I get home though.
Last edited by D17VTECPOWER; Nov 14, 2019 at 11:36 AM.
Do you hear the fuel pump run when you turn the key on? It should run for a couple seconds and shut off. Also, the ECU grounds that wire rather than providing power to activate the fuel pump relay if I remember correctly, but it's been a while so I could be wrong about that. I will check when I get home though.
I did hear the pump come on a few times
i tried constant 12 volts and ground and still no go.
but fires right up with ex ecu
immo still lights up, I know u said it doesn’t matter though
i tried constant 12 volts and ground and still no go.
but fires right up with ex ecu
immo still lights up, I know u said it doesn’t matter though
I will check when I get home, it is possible that having those 2 pins on the ECU connected together could keep it from starting though. I will get back to you on that this afternoon when I get home.
I will check when I get home, it is possible that having those 2 pins on the ECU connected together could keep it from starting though. I will get back to you on that this afternoon when I get home.
It's also possible that your ECU is defective.
I thought the same thing so I actually saw the yellow and green wire right above the ecu so I cut it and then tried the constant and ground there.
I thought the same thing so I actually saw the yellow and green wire right above the ecu so I cut it and then tried the constant and ground there.
It's starting to look like your ECU is defective then. Does it ever fire like it is trying to run, or nothing at all? Do you get an engine light? Or a Drive light for a second when you first turn the key on? Do you have a scanner you could connect to see if you can communicate with the JDM ECU in any way?
