Tricking the ECU with 5 Speed Tranny

[Dr Project]

This is a slight distraction from this thread, but does an LS400/Celsior ~1990 have a combined Engine & trans ECU?

 

[Lextreme II]

Yes... I think only Crown have seperate ecu.

 

[Red Supra]

Why is all this tricking necessary when converting over to a manual? You can put an auto ecu on a manual mk4 supra or convert an auto car to a manual trans and there is no problems with the engine funtions. It seems that the SC400 uz motors use the very same ecu as the mk4 supra.

 

[sbcelicagt]

This thread is an interesting read. I swapped the 1MZ-FE V6 into my 90 Celica and had to deal with the A/T to M/T conversion as the engine I picked up was out of an Avalon. With resistors I was able to fool the computer into thinking the solenoids were functioning, but I was never able to get around the NSW signal, which, IIRC is some sort of speed sensor for the torque converter.


The VSS on this system is sent to the ECM and then the signal is sent from the ECM to the speedometer for interpretation. The signal is slightly different and I have not tried to hook the speedometer directly up to the VSS.

KDog sounds like he mentioned the reason why I was never able to cancel out the NSW signal since the ECU compares both the VSS and NSW to each other.

If you disconnect the VSS the ECM will throw a code for this before the NSW code is thrown. This seems to agree with Kdog's logic.

I ended up sourcing a M/T version ECM and plugged that in. The only difference in the wiring was one ground wire. It seems that the M/T acted as an A/T ECM without the one wire grounding out as a switch of sorts. Interesting bit of info.

I never tested the theory that I could convert the A/T to M/T by the same method.

All this leads up to the reason I am posting in this thread. A friend of mine has an 85 Celica GT-S with a turbo 22R engine. It seems that the California DMV has caught up with him and requires him to smog his vehicle. His current setup has a snowball’s chance in Hell to pass. He is considering changing over to a V8 and I will probably be the one wiring it up since I've had the experience with my own engine.

With that in mind, I have a few questions:

1) Has anyone successfully swapped a 1UZ over, retained the stock ECM, and found a way to clear out all the DTCs(Diagnostic Trouble Codes)?

2) Has Toyota made a V8 vehicle in the last 10 years with a manual transmission option?

OBDII, while a bitch to wire up correctly, offers a lot of advantages and reduces the headache of troubleshooting a car significantly. Because of this, we would probably go that route, but not if the A/T signals cannot be solved.

Thanks in advance for any advice,



Adrian Avgerinos

 

[sideshow]

i dont know how nsw has anything to do with the vss

vss ges to the speedometer at 20 pulses per rev
then gets divided up and goes to the ecu at 4 pulses per rev

nsw is neut start switch this is the start signal straight from the key

sta is the start signal but thru the automatic inhibitor so if its manual it would be just like nsw


the nsw wire is not crucial

the sta is for fuel enrichment at start up

the vss is crucial for speed

did you test the car before u started to fool the ecu

i have yet come across the reason to fool the ecu

 

[sbcelicagt]

I'm at work right now so I will have to check my notes when I get home. On the 1997 1MZ wiring though, the VSS is indeed fed through the ECU first. As for the secondary speed sensor, I will let you know what that actual wire was once I get home.

Two things to keep in mind here:

1)This is not a 1UZ. It is a 1MZ-FE
2)I had to make the car smog legal for California.

So, "crucial" is a relative term. I had to make sure the check engine light does not come on which means no DTCs in the system.

Edit: I believe it was P1765 that I was unable to eliminate.

 

[sbcelicagt]

The "O/D Direct Clutch Speed Sensor" was the problem. It is a 2 wire sensor found in the A/T that interfaces with the NC2- and NC2+ pins on the ECU.

 

[Zuffen]

Toyota make a manual V8 Landcruiser.

I think we've all concentrated on sedans and forgotten the 4b's. There must be some interesting stuff in these vehicles for us to explore.

Do a search on the Web for "tundra Forum" and see what you get.

 

[sideshow]

what i have found is some toyota ecus have 3 main ecu plugs

then theres a plug wghich comes of the side of the ecu

it has 4 or so wires to it

this plug usually has the nc2 wires thats y people forget them

 

[sbcelicagt]

The 1MZ ECU uses a 4 plug design. 3 are from the sensors and various engine bits, and 1 contains output signals for the dash and so forth. The NC2 pins are located on one of the 1 engine harness plugs.

 

[R31-V8]

Thanks to all who have contributed their info. I have a Celsior engine with combined ECU and Traction control. I am backing it with a R154 Supra 5-speed with a speed skid sensor control output which I believe would have fed info to ABS and Speedo on the supra it came from. I am puting it all in to a R31 Skyline and don' require speedo or any other outputs just the engine to drive through th g/box without going in to leap home mode and/or activating traction control.

I am wishing to modify the loom myself and am confident in wiring up all powers, earths, relays up to the point I need to trick the ECU to run properly. I assume I need to do what Kdogs has outlayed in his diagram to make the ECU think it is in neutral?

Is this all I need to do to run the engine properly or are there other things that need to be modified? do I have to connect the g/box output to the ECU so that the traction control doesn't activate (or can this simply be turned off)? If so what modification is required (more detail the better). I am happy to pay for any parts any one can supply to make these mods up to the point where if it is too much of a problem I will just go to a Autronic computer.

I think we should all put together a few diagrams and detailed information on this to post in the sites technical section as a lot of people could benefit from this info.

Any help extremly appreciated. Thanks John, Adelaide, Australia.

 

[83GT400]

Has anybody in the last 2 years that this thread has been dead for tried to use a GS400/Crown ECU with a LS400 loom? Or is there simply no way? Im trying to get a W58 to work with a pre-95 LS400 motor that I would try to swap into a 83 Celica.

 

[sideshow]

yes should be able to be done

not sure what u mean by gs400 that is not a crown

all you have to do is repin the ls400 loom ecu plugs to suit the crown ecu


prob take afew hours if u know what yr doing

is the engine an ls400 aswell


cause where the engine loom plugs into the front cam and crank sensor loom is abit different from sc400 to crown so it might be diff aswell on a crown to ls400


if enigne is complete ls400 and all u want to do is use crown uz131 ecu then should be fine if u do things right

 

[83GT400]

Sorry, Im over here in the states and we have the GS400 and I thought that was the Crown counterpart. Anyhow, the engine would be from a LS400, I desire the front sump. Thank you very much for the info. I wish there were more knowledgeable people here in my area that could help me out with the swap. Is there any place you can direct me as to getting help for the repin?

 

[sideshow]

sorry this is my full time work so i stopped handing info out a long time ago

there are diagrams on this website and many scattered around the web just do a search and u never know what u will find

 

[83GT400]

Maybe make me a custom wiring setup I can buy from you?

 

[sideshow]

it woul take me ages and be pretty pricey to make an adapter loom to go from from loom to another ecu

u can sned me your loom and i can mod it to suit the correct ecu

i have spare ls400 and spare crown ecus so that wont be a problem testing things

im in sydney australia so might be expensive on postage

maybe ask dr tweak i do thoes 1uzs all the time about 2 a mnth and are piss easy

only prob im so flat out at work with about 15 cars to do before xmas so if u did send me your loom u might get it back by end of january

 

[83GT400]

it woul take me ages and be pretty pricey to make an adapter loom to go from from loom to another ecu

u can sned me your loom and i can mod it to suit the correct ecu

i have spare ls400 and spare crown ecus so that wont be a problem testing things

im in sydney australia so might be expensive on postage

maybe ask dr tweak i do thoes 1uzs all the time about 2 a mnth and are piss easy

only prob im so flat out at work with about 15 cars to do before xmas so if u did send me your loom u might get it back by end of january

I dont care how long it takes I just want a 100% guarantee that its going to work out for me. I just dont want headaches. I can get the front half of an LS400 easily but finding a gs400 ecu that will work is not as easy. Anybody know an easy place to find these? Do the 1uzs from each car have to be the same year? Thanks again

 

[sideshow]

take a pic of your ecu of the part numbers and ecu plugs

so u can get a front cut but it is missing the ecu?

i dont understand what yr trying to do

y do u want to use the crown ecu

if u buy a front cut u should get everything otherwise go to another shop

another thing is i see it lal the time

do not buy the front cut or enigne package if its very cheap

too many guys here go for cheap option and get shafted because afew importers know jack **** about this sort fo stuff and the customer always end up with wrong bits or missing bits 1 in 10 conversion wire ups i do end in this way

goto someone who knows what they are doin spend abit more and get everything

for same price for me to make the adapter loom u can buy an ls400 ecu

i have an ls400 ecu but i use it for testing

i have a wiring loom from a crown aswell which i could sell if u want to go that way

 

[83GT400]

take a pic of your ecu of the part numbers and ecu plugs

so u can get a front cut but it is missing the ecu?

i dont understand what yr trying to do

y do u want to use the crown ecu

if u buy a front cut u should get everything otherwise go to another shop

another thing is i see it lal the time

do not buy the front cut or enigne package if its very cheap

too many guys here go for cheap option and get shafted because afew importers know jack **** about this sort fo stuff and the customer always end up with wrong bits or missing bits 1 in 10 conversion wire ups i do end in this way

goto someone who knows what they are doin spend abit more and get everything

for same price for me to make the adapter loom u can buy an ls400 ecu

i have an ls400 ecu but i use it for testing

i have a wiring loom from a crown aswell which i could sell if u want to go that way

I'm trying to get my w58 to work on the ls400 motor and I want to use the gs400 ecu so I don't get any trouble for it. So my plan is to get an ls400 and take anything I need out of it and use the gs400 ecu with the ls400 wiring for ease of install. Only big problem for me is finding a gs400 ecu that isn't attached to a car.