Tricking the ECU with 5 Speed Tranny

[Lextreme II]

Hey Gang,

I have been thinking about this. How can i trick the stock ECU with a 5 speed transmission. I was thinking using a resistor or a power line into the wire Parking (P) or (N). The nuetral switch is located on the right side of the tranny. Tricking the ECU thinking its on P or N. Secondly we also need to trick the speed sensors (1 & 2) with in the tranny itself. The speed sensors are located on the left and right near the rear portion of the tranny. Making it think the car is not moving.
What do u think and inputs please.

 

[Miles B]

I intend on bridging the neutral start switch, and telling it that it is permanently in neutral, or maybe park. I think this will let me take the key out. It also needs resistors where the solenoids are, or it can get angry. As for the speed sensors, my R154 has a spinning gear output for a cable speedo, and the electronic ABS sensor. I intend to make my own electronics to interpret the ABS sensor's output, and make 2 new signals - one like a hall effect and one like a reluctor. These are the 2 stock auto speed sensor outputs. There is also possibly a third sensor to worry about, which tells it if the torque converter is slipping.. not sure on that one yet, need to read up on it. If you got a box without the ABS sensor, well, that's gonna need some kind of thing made up to have the cable spin a signal wheel or something. I don't know if that's available.. I'd hate to have to make it.

Another thing I have considered is that the ECU may have different maps for neutral/park and drive. In this case, I would tell it that it is permanently in drive, and when you pull the handbrake, it's in park. That sounds a little more suitable to me, but then you get the problem that it will try to change gears (retarding the ignition). Perhaps tell it that it is permanently in first and hope it doesn't get angry when it sees it is doing 100 in first gear. It is a real shame the shift arms don't have some type of gear position sensor... no real reason for Toyota to do it, but it would make it really nice for things like remote start alarms etc..

 

[KDog]

You only need to short out the two large middle pins on the 4 pin row on the gear select switch. This will make the ECU think the car is in neutral or park. A blade fuse fits in perfectly.

With the ECU in neutral you will not need to connect resistors to act as solenoids.

You will have a nightmare of a time replicating all of the signals required if you want to have the ECU in drive.

You will either need to disconnect both speed sensors going into the ECU or have both there. After a certain amount of time the ECU will spit out an error code if only one of the speed sensors is getting a reading. Depending on which manaul box you use you may have a speed sensor output. I would connect this to the dash but cut the wire going from the dash to the ECU at the ECU end, so that way you should be able to keep cruise control, trip computer etc.

 

[KDog]

Yes defeating the neutral start switch is the best way. A blade fuse happens to fit in the connecter nicely.
You may need to remove one of the speed sensor wires that goes to the ECU at the ECU side to prevent error codes. The should still drive fine but the car will spit out an error code if it recieves only one speed signal after you have been driving for a while.
You do not need to worry about placing resistors in to act as the solenoids, nor do you need to worry about the TC/OD speed sensor.
If you want to simulate drive then you will need to simulate a lot of signals which is going to be quite difficult. Tricking for 1st selection may be better. You would only need the 3 speed sensors and the solenoid to be tricked.

 

[sideshow]

i have wired afew 1uzs withmanual gboxes and have not yet had to trick them
mind u the cars went ok and physically couldnot find any prob

maybe puttin an air fuel ratio meter up thee exhaust to check mixtures would be a way of testing
but so far i have not had to trick any ecu when runnin manual gbox

 

[Lextreme II]

Sideshow,

The 1uz you are talking about from Crown or others. From what i have heard from the experts in this forum stating Crown has two seperate ecu. Would this apply to those of us with U.S. Spec. 1uzfe?

 

[sideshow]

i have wired two crown 1uzs with only the engien ecu and a manual 5 speed
one had a prob but that was due to fuel system not working properly

i have wired a lexus 1uz from ls400 behind a manual and no probs


i have wired a 1uz from a soarer think sc400 into a 4wd but that hasnt started yet project still goin so dont know bout that yet


the car i did have probs with was my own crown 1uz with auto but thats all sorted out now

so i recon just wire it up then if it does play up then much round with these tricking signals

i have read people say just need 4 or 5 wires to wire these up
that might be accurate if u put all ignition wire together or all start wires together and all battery wires together
if it is that easy why does it take a full day to wire one of these up

but so far the way i wire them up has not caused me any probs

im wiring a loom on the floor for a customer the engine loom is a sc400
cut at firewall and the ecu is a ls400 cut just after ecu so hope this all goes well then i will be able to do looms at home

 

[Zuffen]

Sideshow,

I agree with you about wiring the ECU up.

Whilst you only NEED 12 wires connected you will be short a lot of things.

I took days to think out my wiring then actually do it. Doing it was the easy part.

If you just group all the ignition/power wires together the poor ECU will forget what it has learnt each time you turn off the ignition. It will never run well.

You need to do it right or get it done. Part of doing it right is a neat job. I saw a photo of a 1UZ in a 4x4 (no names or model the owner may get upset) and the wiring worked but it was a dog's breakfast. There is no way you could fix a problem that arose in the field.

I don't think it is hard to do but you do need to understand a bit about electronics.

 

[Lextreme II]

I have read ALSC last night Neil Griffiths had sucessfully install a W58 in a V8 (1UZFE). The thread didnt say anything about computer control or modifications.

 

[KDog]

You are correct it didn't. The info is still proprietry including problems which will occur.

 

[cseufert]

Hmm, i thought all TCCS ECU's will not be happy when the engine keeps revving above 4k without a speed reading?

 

[KDog]

Yes that is correct. But on a manual gearbox you still have one speed sensor which you can use. However, minor problems do occur with only using the one speed sensor.

 

[1uzHilux]

KDog,
Firstly, thank you so much for providing circuit diagrams for the mighty 1UZ. You should be proud of the hundreds of enthusiasts that have you to thank for helping bring their projects to life!

Now, I know I'm sounding like a broken record here, and must be the 1 zillionth person to ask this, but exactly what sort of "minor problems" will I see if I'm using a manual with the uzs131. At the moment, I've got the beast running with a w58 attached, 1 speed sensor at 4p/r direct into the ecu.

Lately, I've annoyed most of my neighbours by running it at around 4-5000rpm in a couple of 15 minute bursts, but haven't had any issues so far. It isn't really loaded up, as its sitting on a pallet, but what am I to expect once its in my ute?

N

 

[elhsupra]

Kdog
Do you know what two wires these would be at the ECU end. My wiring harness had all the wires to the auto cut. 2, L, P, R, BK, KD, SLU, SLN, IG, etc. This is from a 92 LS400.Thanks alot for all the help and the many wiring problems you have solved on this board

You only need to short out the two large middle pins on the 4 pin row on the gear select switch. This will make the ECU think the car is in neutral or park. A blade fuse fits in perfectly.

With the ECU in neutral you will not need to connect resistors to act as solenoids.

 

[KDog]

1uzHilux
Sorry for the confusion, I wasn't very clear as I have been dealing with SC400 owners lately not conversion people.
You should not have anyproblems with the ECU when the engine is in your car. The problems I have encountered are in sc400 where other ECUs are invloved ie cruise control functioning etc. AFIAK the car didn't have any problems apart from this and the associated error codes coming up when the car went over certain rpm. I didn't get a chance to read what the error codes were though.

elhsupra
Sorry I can't really help that much as I don't have the diagrams fro your car and I believe the setup for the gearbox switch is a different setup to the sc400/crown.
You should just be able to ground the NSW line on the ECU. As far as I can tell it is pin 14 of the 22 pin connector and may be Black with a white stripe. This is about the best guess I can give you at the moment.

 

[Zuffen]

Elhsupra,

Look at the diagrams in the technical area. I think you will find what you want. Whilst Toyota are prone to colour changes from year to year of what wire does what I would expect you can work it out from pin numbers inthe diagrams so you can work out where the cut ends should go.

 

[elhsupra]

OK. One more stupid question. If I understand what everyone is saying and the wiring diagrams for the LS400 and Kdog's Crown ECT pinout diagram corectly then all I have to do is:
12V ignition power to the NSW pinout on the ECU(14/22)
This would simulate the car being in neutral right?
Thanks everyone

 

[KDog]

Almost but not quite.
The 12 volts needs to come from the start switch (not ignition) and then is conneceted to NSW (14/22).

The start 12Volts also needs to go to the ignition realy (so check that this wiring is there) otherwise you ignition system won't have any power when you are cranking the car.
You may also need to hook up the cold start injector to the high current side of the starter relay to help with starting. It goes through the injector and back through a timing circuit (as the injector isn't on the entire time the car is in start mode) back to 12volts start. It may be easier to leave this (I would) out if you don't have the timing circuit.
The 12volt start from the switched side of the relay also need to go to the STA pin on the ECU. I believe this is a black wire pin 2 of the 22pin plug.

I will try and do a wiring diagram to clear this up

 

[elhsupra]

Ok. So for me to connect my R154 to the1UZFE from a wiring standpoint all I would need to do is is source power for the NSW input at the ECU from a start power source...not ignition, right? And the not worry about shorting out any pins on the selector switch since since that wiring is cut. Thats great! I might actually get my 1UZ power MA61 running in under a month now. Thanks for the diagram KDog.

 

[1uzHilux]

Thanks Kdog for clearing that up for me.

Its only a matter of time now before the 'lux is totally ready.

Cheers

N