Factory ECU without Tranny Control

[Lextreme II]

Hey Gang,

I am trying to get this project up. http://lextreme.com/forums/showthread.php?p=9654#post9654 I wonder if any experts can help me with ecu. I would like to run stock ecu, but the tranny will be VW transaxial. Its it possible to run the stock ecu with out the control of the tranny? Would it affect the stock ecu functions?

 

[Zuffen]

Lex,

Why not buy a Crown ECU and wiring loom from Australia or NZ. This will run happily without the trans or the ECT.

Shouldn't cost too much.

I'm sure someone on this Forum would have one or the other floating around.

If you can't locate one let me know and I will check out some parts suppliers down under.

 

[KDog]

The only thing (simple) I forgot to try when fiddling with the Soarer was to short out the Neatral start switch so the ECU thinks the gearbox is in park/neutral all the time. If this doesn't fool your stock ECU then you will need a lot of electronics (to simulate the speed sensors) to get it to run. Or just try and get a Crown ECU.
Give it a try and let me know.

 

[Lextreme II]

Zuffun and KDog,

Why Crown ECU? I assume its only slightly different from the US Spec no? Why Crown ECU can make this project possible?

 

[KDog]

The Crown Royal Saloon has two seperate ECUs. One to control the engine and one to control the auto. The engine ECU doesn't seem to mind if the Auto ECU isn't there which means you can run any gearbox you want. The SC400/LS400 with an integrated engine/trans ECU doesn't run the engine very well when the auto isn't present.

 

[Lextreme II]

Thanks KDog,

Good to know.... I wonder how different is the US LS4/SC4 loom to Crown Loom.

 

[sideshow]

hey guys
i have wired up a lexus 1uz with 5 speed manualk

and 2 crown 1uz with 5 speeds

and a crown 1uz with 4 speed auto

the manuals had no bloody errors
so i dont know what others have been doin
maybe htey fukt something up

but my crown 1uz with 4 speed auto is causing afew headaches


i have figured its easier to run manual and leave auto **** out
because tryin to replicate same signals to the auto as they should have
in the crown is a pain in hte asssssssssssss

u caanot use diff looms

i have a soarer loom which is cut
and im goin to extend wires and mate to a lexus ecu
thats ok but u cannot plug a crown ecu on a lexus or soarer wiring loom and engine
it wont start
prob need to reconfigure wires to ecu

 

[Zuffen]

Sideshow,

this will sound stupid but have you tried different ECU and ECT's? Could you have a dud one? You're welcome to borrow mine to try if you wish.

I'm on the Upper North Shore.

I also have a complete SC400 in bits I am about to send to the tip so you could get the ABS computer from both the SC and the Crown if you wanted them.

 

[sideshow]

i need an abs ecu from a crown

the abs ecu from a lexus is different i think

my auto runs 95% ok

like its nto really a prob

but i just want to do all these tests on a std crown front cut so when i wire up customers cars i can tell them this is what is also needed

im not really worried bout how my car goes
just really using it as a test bench

the auto ecu is still spotting out code 61 which is abs speed sensor no2 not working

so untill i fix that error in the ecu ill just drive it as it is
cant really blame the mechanicals until code 61 is fixed
now as i drive the o/d light flashes once every 5 seconds
its annoying but hope to fix it soon

i have a unit connected to speed signal and by adjusting it i can control when the auto changes gears

but im just tellin people that wiring up and auto is not as straight forward as the manuals

 

[sideshow]

hey zuffen

any chance u know if yr abs ecu came from a crown half cut

i know of 2 abs ecus but they are off a lexus
im not 100% sure if they fit

i have been told by toyota that the crown has diff part number so i gather theyre different

if i could borrow the abs ecu and do some tests i would be grateful
as i cant get one very soon

but i need one form a crown

what is the part number on the abs ecu??

 

[Zuffen]

Sideshow,

You're welcome to my ABS ECU.

I took it out of my Crown half cut. I kept the tails of the loom with it so you will have all the plugs. Just trying to make it easy.

 

[sideshow]

hey zuffen

i wired up the abs ecu
seams ok no more error codes but all i did was drive it round the block
tomorrow ill drive it to penrith for a job and see how it goes


ill adjust my speedo box to get the speedometer reading corect then i will see if the gbox still changes gears at the correct time

i have measured the signals

i know the ratio of rpm difference in and out of the abs ecu
now all i need is to make sure the signal wave is the same
if thye are the same then i should be able to buy a device to have the correct rpm signal into the auto ecu from the abs speed sensor

hopefully by next week it will all be finished
thanks for the ecu

 

[Zuffen]

Sideshow,

If you manage to solve the impulse problem you are one step closer to make engine swaps more achievable for others.

Just as well I didn't throw the unit away.

 

[KDog]

Ther are wuite a few devices around that are designed to change speedo and tacho readings. Dakota digital makes a nice one but its too expensive to buy in Australia. They all seem to be around the $300 mark here, well at least the VDO and DD one were.
Making your own is the better option.

Despite my previous claims it is possible to get a SC400 ECU to run without the auto tranny. I can assume that the ls400 ECU is the same.

 

[thefastj]

i THINK JayCar have a cheap kit also..

 

[KDog]

Jaycar kit won't be out till september. Also it can only divide the signal not multiply it.
I am surprised no one has made an analog version. Its much simpler and gives much finer control over frequency adjustment. The one I made for my car works this way. You just need a F/V converter, a DC level adjuster and a V/F converter.

 

[sideshow]

hey kdog

all is fine now with my hilux

for 200 bucks its easier to buy a kit already made
it looks to complicated for me to make im just a mechanic


soon ill do measurements
like at this rpm and this speed

the pulses are .............. for abs
and ..... for the input to auto tranny

then ill just buy a digital converter to divide the signal

i already habve one ion my speedo

so now my speedo read accurate
gbox changes accurately
and i think it has stopped pinging

soon i will see if the fuel econoimy is better



and one day ill make a book on this info and maybe become rtich and wealthy heheh nottttttt

 

[KDog]

That's good news.

If its a straight divide by an even number than it would be way cheaper to make a circuit. If its an uneven number its better to do it an analogue as the digital method is not accurate.

From memory the ABS divides around 4, does this sound correct??? Can't find my notes. If this is the case then a simple circuit with some flip flops and some transistors would do the trick.

 

[sideshow]

well i still have to find what the signal type is goin in and what it is goin out

i will do that one day when i can get a friend to drive my car and i run some tests

 

[KDog]

Are you bringing your car down with you?????
With should meet up. I'll bring the scope.