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Ecu help
Posted: Wed Dec 11, 2013 3:31 pm
by GreenyUK
Hi all to start with I wasn't sure where this best fit, either electrical or engine.
So mods please move accordingly
Right I've just bought a ukdm 4th gen prelude. It has the Jdm H22a fitted and running with the original uk Ecu.
Now I want to fit the Jdm Ecu to gain full benefit. I've been told the only difference is the Jdm unit will have a knock sensor which ins't an issue at the minuet as the uk Ecu isn't looking for it.
So to install the p13 jdm Ecu I'd have to add the wiring for the knock sensor, am I right in thinking I can grab the switch off another car then solder the length of required wire to it then insert into the back of connector D pin 3.
Is this correct and would it work?
Posted: Wed Dec 11, 2013 3:34 pm
by indigolemon
You'll likely find the internal wiring from ECU to strut top in engine bay has the wire. You'll probably only need to add it to the engine loom. But then, if they used the JDM engine loom, you might be plug and play ...
Posted: Wed Dec 11, 2013 4:16 pm
by GreenyUK
Hey man.
Ah really that be make life much easier

I'll have to check I've read it's a red/blue wire do you know if that is correct.
Plug and play would be great.
Just have to source an Ecu now of and find my spoon chip I bought from sleepy like 6 or so years ago haha
Posted: Wed Dec 11, 2013 4:30 pm
by K30DPC
There is one more difference. In underhood fuse box jdm has some current sensor or something like this which UKDM doesn't. To do this swap properly fusebox should be changed and LMA (I think this is how they call it) connected. This doesn't fireing dash light by itself but always will show fault with any other (like for e.g. if you have o2 sensor fault then dash lights will come on, and if you do selfdiagnosis then you will find o2 and this one). Not sure how this affecting engine performance, but probably it's not
Posted: Wed Dec 11, 2013 4:35 pm
by indigolemon
This is true, but you can get away with skipping the fusebox swap, my car is using the UKDM 2.3 fusebox still with no issues - but yes, you do get the code. Thankfully it doesn't trigger the CEL or affect performance though

Posted: Wed Dec 11, 2013 4:56 pm
by GreenyUK
Ah right I didn't realise this k30 thank you,
I'll see how it goes if it doesn't bring the light on and I feel no difference in performance ill prob leave it lol
Posted: Wed Dec 11, 2013 5:20 pm
by indigolemon
Just looked it up - it's called the ELD (Electrical Load Detector). Throws a code 20.
Posted: Wed Dec 11, 2013 6:00 pm
by K30DPC
indigolemon wrote:Just looked it up - it's called the ELD (Electrical Load Detector). Throws a code 20.
this is what I meant

Posted: Wed Dec 11, 2013 6:20 pm
by indigolemon
K30DPC wrote:indigolemon wrote:Just looked it up - it's called the ELD (Electrical Load Detector). Throws a code 20.
this is what I meant

Totally man! Knew exactly what you were talking about but couldn't remember what the heck it was called

Posted: Wed Dec 11, 2013 7:59 pm
by GreenyUK
Never heard of that lol is it important? Lol