The AUSubaru.com.au Forums

Yo Subie Dudes! When I fit my EJ20 into my EA82 L, I read that I will need to wire up an Engine Check light... What for? And if I need it, How do I do it?
Thanks to all of you!!!
PS I'm an Electronic Engineer so don't hold back!

You need it to assit in fault finding and to make you aware when there is a problem with the engine or a sensor.

Not essential... also some EJ ECUs have a viewing window on the side of the module (Just a hole in the casing). If it has this window you should see an on board engine light.

The engine light is a Negative signal (i think, i can confirm if needed).... best bet is to get a LED light set up that can run off 12v... Repco is where i usually get them from. Wire one side to IGN and the other to the correct wire coming from the ECU... i can probably point u to the correct wire on the ECU if you have a 4 plug EJ ECU.

Dave

Dave - thanks for such a quick reply! And thanks for the info - OK makes sense now, I'll definately hook one up... little blue led might be nice! (or do I want a honking great red flashing light?!@#)

LOL... no small LED is good... and not one of them ultra bright ones. Sorta like a imobiliser style LED. A bright one will drive you nuts at night if the light comes on.

Dave

88 Touring wagon.......by any chance is this the EFI version of the car?
If it is then you should already have a check engine light in your dashboard...

Naw - I just got the carbie version... hence the passion for fitting an EJ20!!!

OK - try this one - I believe there are only 8 wires to connect the EJ ECU to the EA wiring loom. Do I simply have to connect these 8 wires from the ECU to the respective sensors on EJ plus a power supply/ignition switch?
Or is that too easy?

im not sure on the number of wires... never really counted them... but it sounds close... some of the things are not needed some are. Biggest job is cutting the harness down and getting rid of all the extra wiring you don't need. Also re-wiring the ECU operated engine cooling fan with a relay. The existing cooling fan wiring is built well into the harness and it's usually neater and less complicated to chop it out and re-do it.

The 8 wires would not include the 20 odd that go to all the motor sensors... the 8 im refering to are things like power feeds, earth wires, Tacho, Engine light, temp guage, oil light etc.

I think you think it is easier than it actually is. One wrong wire cut out of the harness and it wont run... one wrong wire hooked to a power feed and isn;t meant to be could blow the ECU. You really need to understand whats going on to do it. I have a ECU pin out of the 4 plug EJ ECU harness which i find very useful. Also the Gregories Liberty manual is priceless for helping with this wiring.

Dave

Thanks Dave - I have been trawling through the posts for months now and have found precious little electrical details. I didn't think it would be simple but thanks to you I now have a much better idea. I have no problems building wiring looms from scratch, if I have to - I was trained to do this and I fully appreciate the potential damage caused by one wrong connection!
I am compiling a 'manual' on my EJ conversion and am trying to nail down as much of the job as possible before I even start cos I don't want too many surprises whilst I'm doing the job.
I appreciate all of your advice and I'm sure I'll have heaps more questions before I'm done...
regards, Justin.

I paid $300 to have someone strip down a harness, came with tags on the wires and notes telling which wire to connect to what. Doing it this way was as easy as installing a stereo.

My only issue has been that i havn't got a speed sensor, can drive the car around the suburbs for weeks with no issue, but once on the freeway at 100km/h the warning light comes on, i have just got used to re-setting it.

how does the ECU know of your going over 100 on the freeway if you don't have a speed sensor? I have never had my speed sensor hooked up... it spits the speed sensor code when i check the codes but it doesn't ever pop up when im not in any of the test modes. As far as i know all it does is limit your speed.

I thought that the L series had a speed sensor wire behind the speedo too... might only be on the EFI models though.

Dave

Dave,

I have no idea, all I know is that the light comes on and the only error code that comes up is the speed sensor, occasionally there is another one too which I think was the knock sensor?, can't recall as I have only clocked up about 800km in 12 months since buying the outback

rob