Mystery ECU in a L2 Mira

Man_With_Some_Miras · February 28, 2025, 4:26am

TLDR: Where and what did this green stickered ecu come out of???

Hola Hombres, long time stalker 1st time poster.
I have been trying to get one of my nuggets to start for the last couple weeks, gone through all the checks to see what could be broken, shorted or seized had gone through a bit of a “parts till it starts” phase of sorts, which yielded some fresher components but not much of the engine actually running. Come to tearing the dash out to do a bit of arts and crafts to reel me back into reality and not selling this box of shit, when I find the ECU pictured below:

Being as fortunate as I am to have 2 shells, I pulled the other ecu out and it was a standard black and white stickered AUSDM ecu. Comparing the pinouts below I couldn’t tell what ECU this green stickered one came out of, but it could be the cause of every single issue I’ve had up until this point, all the electrical seems to work just fine there’s a good supply of voltage where it needs to be but trying to turn the thing over seems to be impossible.

Checks completed so far:
Injectors: working and flow correctly
Dizzy: Known working part could also be an issue in this but thats going to be a slight after thought right now
Harness integrity: Intact and all breaks or loose ends tied and capped
Fuel pump & accompanying electrical: Fuel pump works, does actually pump fuel, the relay on the circuit does not seem to want to switch over (could be due to above mentioned ecu)
All available relays: swapped for new or known working parts
Fuses: Checked and intact 1 of the efi Fuses was poped switched that out but did not seem to remedy the issue

There doesnt seem to be a diagnostic port available to probe and prod to see what the actual issue is, not under the dash nor in the engine bay.

SO, in conclusion I’m either completely stupid for flying blindly into this. Or this ECU is the root of all evil and once I de-pin the connectors and swap in the AUSDM ecu all will be fine, updates to come.
But any and all input, knowledge and information would be greatly appreciated

evilhighway · February 28, 2025, 8:50pm

I haven’t read all the pinouts you have written but it looks like a standard series 1 L200 ecu. I also can’t remeber what colour the sticker’s should be
Have you swapped the igniter in the dizzy?
I had a mira years ago that I just could not get running. and when I swapped the dizzy it worked fine. ( I had a few dizzy’s at the time.
Forward a few years and I had an old 1984 swift that I thought the coil died in and after much investigation I discovered it was the igniter in the dizzy, For some strange reason a spare one from an L200 fit and the car worked wonder’s also.

Also your second shell seems like it may have been engine swapped and generally L200 ecu’s are not black and white with ausdm on them.
They are usually like what you have there in a series one and the seires 2 is similar but smaller but has arms so it can bolt into the same spot however the pinout’s are different.

Man_With_Some_Miras · March 2, 2025, 4:21am

I relation to the dizzy, swapped out the whole unit for a known working one from the shell with the black and white stickered ECU shell so that’s a definite on the good side. But the info I got the sticker colours from was that thread about ecu pinouts

^
This one to be exact. So really I’m just grasping at straws here

But I have ripped out the nerves to the engine on both shells and discovered some mad dodgy wiring from whichever previous owners handywork, so I’m in the process of patching things up and documenting changes, sorry for no pictures life is grasping me waaayy too tightly right now

evilhighway · March 2, 2025, 9:06pm

Ok I do apologise, for some reason my brain read black and white ecu and not black and white stickered ecu. Well I guess you sorted out the dizzy part so that is not the case.

Hopefully its the dodgey wiring. that other thread shaws the size differences between seris one and series 2 ecu’s,
Have you tried the ecu out of the other car? I am presuming the plugs are the same and they are the same series. If that is the case that they are the same series then I would definately try swapping to see. I guess it is possible that the green stickered one you have is a dodgey turbo one.
With getting ecu’s running in Mira’s it is usually a couple of power and ground wires to get them running when doing a swap.
I will be very interested to see what it is after you have worked it out.

Man_With_Some_Miras · March 3, 2025, 3:51pm

Latest half ass update: this box of shit is going to make me Ev swap it at this stage.
Swapped out engine harness. All 6 wires of the thing. Still doesn’t like it and refuses to start. And now the fuel relay doesn’t want to click over
If there’s any info in a ecu diagnostic pin on the actual ecu itself. Not a random port somewhere. Just to see what the actual fuck is wrong with it, that information would be greatly appreciated. Otherwise I’m still @ a standstill. Looking into coil on plug conversion, or even a standalone ecu and re-wiring the entire thing so I know for a fact it’ll work.

Or even what ohm readings I should be looking for on all the components known to shitting themselves and not telling anyone, that would also be greatly appreciated.

Remedies tried:
Verbal, psychological & mild physical abuse
Probing. Every. Single. Possible. Point of electrical contact
Searching for any other vehicle to work on
Hayabusa swaps