HELP!!! ECU wiring diagrams

[Mudman]

I have almost finished my 1uz into my hilux transplant and made a start on the wiring.
I bought the engine with an uncut wiring loom and I think it may be out of a 1991 LS400. It has a front sump, hydraulic fan, and 1991 written on the HT leads.
The ECU for this engine has three 40 pin plugs. Two of the plugs are joined together to form one unit and is bolted to the ECU through the centre of the 2 plugs.
The engine number is 1UZ 0267477 and the ECU number is 89661-30500 (175000-4911-12V).
I have aquired a crown ECU which I've been told is much easier to wire up, so Im going to try to use this instead of the original ECU.
The only problem is that I can't find any wiring diagrams to match my original ECU.
I have spent hours searching different sites and the best I can find are the diagrams on this site for the crown ECU from KDog (which will be very usefull)and diagrams for a 1992 Lexus SC400 which don't match my ECU.

If anyone has diagrams for my ECU and are willing to provide these, it would be very much appreciated.

 

[Mudman]

I'v just been to North Shore Toyota (Auckland, New Zealand) to try to buy some wiring diagrams but they couldn't source any. However, they did tell me that according to the numbers on my ECU, it was used in a 1991 - 1992 Toyota Crown Majesta.

Also, another reason I'm using the earlier crown ECU is because it runs the engine only. This is more suited for my transplant because I have used the original R150 manual transmission from my hilux which does not need a computer to run it.
Apparently from my limited understanding, my original ECU runs the engine & auto and needs both to work properly.

 

[Zuffen]

Mudman,

The Majesta, SC400 (& Soarer) and LS400 (& Calsior) used an integrated ECU/ECT.

The Early Crown used separate ECU and ECT so it's easy to separate them.

The easiest way to do the swap is to source an early Crown wiring loom and swap them over. This way you could sell the complete Majesta loom/ECU and recoup your money.

Trying to get the Crwon ECU onto the Magesta loom will entail finding the correct plugs for the Crown ECU off a loom.

 

[Mudman]

Thanks for the suggestion but I've already tried to find an earlier Crown wiring loom and unless I bought a complete engine, they are next to impossible to get. However I will keep trying to find one because like you said, it would be the easiest way.

I already have the earlier Crown ECU and matching plugs and I'm thinking of splicing them onto my wiring loom (If I can source a suitable wiring diagram).

 

[sideshow]

if the loom and ecu are a matched set then use them
the 40 pin plug ecu is a soarer stlye ecu

u can use it woth a manual gbox with no probs at all
i have done 20 to 30 1uz and never had probs like others go on about when goin to manual gbox

mixing and matching parts can turn out to be a headache in the end

just wire up what u have if its a matching set

i got an email from a guy in NZ he said an auto elect charged him 6800 to wire up his 1uz

i said **** for 3000 i would have flown over and done it hehehe

 

[Mudman]

If you're right, that would be great.
The only problem is finding space to put the 3/40 pin plug ECU because it's quite a bit larger than the earlier crown one. Besides, the earlier crown ECU looks almost identical to the original Hilux ECU for the 2LT diesel engine and it also fits in the same location without modifying any of the mounts. Even some of the plugs are identical.

I think I'll stick with the earlier ECU.
I just need to find the right wiring diagrams to suite my original ECU for the 1UZ.

 

[sideshow]

as long as the loom matches the ecu
otheriwse its a big job tryin to get a soarer loom to match up to a crown ecu

i personally wouldnt do it that way

get crown ecu and loom

 

[hi-lex]

try this link, I used it to wire a mjesta ecu http://www.reanimotion.com/toymods/MX83_1UZ_EngineWiring.htm

 

[Mudman]

hi-lex,
Thanks for the link!!!
I checked it against the plugs on my wiring loom and some of the colours match but most are different. However, I traced a couple of the wires and they seemed to match what the diagram said. Also, where wires are missing on the diagram, they are missing on my loom so I guess that could be a sure sign that it will be ok.
I guess it's possible that there could be some differences because the diagram on the link is for a 1993 model, and my engine is a 1991 but if this works, You've just saved me a hell of a lot of time!
Well... I actually have a friend who is an electrical engineer and he is helping out with most of the wiring so we'll have a go at getting it going in a couple of weeks.
I've just started on my exhaust (from the headers back) and should be finished in about a week.
I'll let you know how we get on.

 

[KDog]

The Crown Majesta is a match for the Soarer SC400 ECU wiring. any SC400 wiring diagram will work for you.

 

[hi-lex]

mine was the same, the sc400 diags have diff colours again so even more confusion, the pinouts are the same like kdog said, I used a sc400 ecu in mine an kept the maj as spare

 

[Mudman]

Thanks for the reassurance!!!
I'll have a crack at firing up the beast in a couple of weeks. Its been 11 months since I started this conversion. I thought it would only take about 6 months but I guess its the same old thing... These projects always take longer than you think.

 

[hi-lex]

I rewired min after swapping from crown ecu in a day inc swapping harness, its not that hard, just gotta concentrate an do it in one hit

 

[Mudman]

A few more questions for you guys,

1) the crown ECU wiring diagrams don't show a starter input to the ECU, I guess the starter signal (50) should be connected to STA (pin 11 in the 22 pin ECU connector)?

2) The crown ECU is looking for a IGF (ignition confirmation) signal from the ignitors, but the 1UZ ECU wiring pinout doesn't show this signal.

3) the 1UZ ECU wiring pinout has pins 25,26,27 labled as G2,G1, and NE position sensor #61, are these returns? and can they be spliced together and connected to the -G position sensor return pin on the crown EUC?

4) The crown ECU requires an ICS ? signal from the air flow meter, however the 1UZ ECU pinout shows a KS (karmen vortex signal) output. Are these two signals compatible?

5) do both TPS need to be connected for the crown ECU to operate correctly?

We are close to turning the key and would like to be sure!!
Thanks

 

[Peewee]

This is what I used for wiring up my Soarer loom into my Cressida.
If you have a complete soarer loom, keep it

DO NOT swap to the crown loom.
For one the injectors are different sizes, so you will over fuel badly.
A crown loom WILL NOT plug into all of your sensors either. The o2 sensors, the knock sensors are different clips.

 

[Peewee]

 

[sideshow]

did u go out and buy a cut loom
if yr did yr bloody mad
u can end up with more headaches

g1 g2 etc should not have to be touched
same with any of the tps wires

 

[Mudman]

This is what I used for wiring up my Soarer loom into my Cressida.
If you have a complete soarer loom, keep it

Thanks Peewee!

Thats a really good wiring diagram and pretty much matches my loom perfectly apart from some of the colours on the pin-out diagram being different.

I've decided not to change the loom, but Im still thinking of attempting to match the relevant wires to the earlier crown ECU.
I know of a few other people who have done this without any problems and they reckon it's a much easier ECU to use when using a manual transmission.

This ECU looks almost identical to the original ECU in the Hilux and it even bolts up to the same mounts, making it a very tidy installation.

If I used the ECU that maches my loom, I will have to re-mount it somewhere else because it won't fit in the location where the original Hilux ECU was. This probably doesn't sound like too much of a problem, but the only other place I can think of mounting it would be under the passengers seat (which I don't really want to do) because it won't fit anywhere under the dash.

 

[MacroP]

Here is what I did for my project car using a UZZ31 donor engine and trans. Similar to Peewee's layout. CA1 and CA2 are the connectors in the engine bay above the A/C compressor. The others are internal for the ECU, cluster etc etc. Two are not listed, these are for the TRC ECU.
There' a few blanks in there but I have found the origins of all but one wire. I haven't got my notes here with me to update the excel file yet.

 

[Freddy 4runner]

I have the same problem as Mudman, the 40 pin plug that came from my UCF11 has different coloured wires in differen locations as what you guys have posted, the part number is 89661-30500, i'm a little confused, can anyone please help?