DTC Codes and what to do with them?

[Handgrenade]

And a transmission guy on another car forum has said this:
Your code 42 for vehicle speed has nothing to do with NSW and STA. As has already been said, the speed signal from the gearbox can't be fed direct to the ECU, it is conditioned in the dash cluster, this is what is screwing up your shift points and giving you code 42.

 

[Handgrenade]

This is how I initially wired the car:

It still started in any gear and I think I had the starter signal code, but can't remember. It's been changed so many times now, I have no idea where it's at.
Right now, it has code 42, code 43 and it shifts early, has shit for power.
All other codes gone and it revs out and idles fine.

 

[sideshow]

I used to hook up the spd signal to an injector output on older Toyotas and this would solve code 42

normally starter dtc is 51

 

[sideshow]

also cut both sta and nsw wires
this will make sure it wont go into limp mode due to them wired wrong

then once u get it running good u can connect them back up when u figure out how they go

 

[Handgrenade]

I suppose I will try to find an injector signal and connect it to the spd signal and see what happens. Fingers crossed, and thanks. I'll get to it tomorrow night and see.

 

[George_R]

The trans guy on another forum is a bollock
Be sure to translate it to him exactly as it appears here

Because if you take perfectly running LS400, mess with the wiring a bit to set 0v at NSW , and go for a drive, you will see DTC 42

 

[sideshow]

does he know 42 is speed sensor not sta or nsw

I had a shop here tel me they tested 1uz trans on their trans dyno
I asked did it get all 4 gears
they said yes
I said did u power anything up
they said no we don't need to

so I laughed at them and said do u realise u will not get any gears unless u power
the solenoids up
he then tried to get out of it
so I said mate stick to your old trimatics and leave the new shit to someone who knows hehehe

 

[George_R]

People tend to read service manuals through and never go into much details
Like a few posts above in this thread, with DTC # 12 . One reads "crank angle sensor" and never gets interested in the remaining text.
dtc #42 is the same story, there's more than one fault condition that can trigger it.

 

[Handgrenade]

I am glad you guys know your stuff because this is the first electronically controlled automatic transmission that I have ever transplanted into anything. I'm learning, slowly but I'm learning. When I get home tonight I will make an attempt to cause the NSW wire to deny a ground to the starter circuit and see what happens. I have not done the injector signal, I have to get the NSW and STA wires right first.
The thing about that diagram link:
I have a starter relay. I made it my starter relay, It's from an MK2 MR2 actually, but all 4 pin relays are the same. You have one 12V pin, one ground pin and when you energize it, the other two pins are continuous or have continuity, with whatever you've connected to it. In my case, when I energize my starter relay, the continuity pins are 12v. It looks as if those pins on his diagram link are ground? Mine isn't wired that way.

How do I make the NSW wire disconnect the relay's ground? Don't earth it to the chassis, see if it will earth with the indicator switch on the trans? But when I check volts on both NSW and STA, after main power is switched on, they both have 12V. If I stick one of those wires to the chassis, shit gets hot, real fast.
Not sure how to make this circuit properly function.

 

[George_R]

Wilbo's article clearly depicts the proper diagram for starter relay and NSW wire
Read it thoroughly

Of course you can use any 4-pin relay capable of delivering over 20A, there's no magic starter relay that only fits this particular application

 

[Handgrenade]

Forgive me George. I just cannot grasp what the hell is going on here.

I lost my temper on another forum and I have copied it here, so you can see what I am dealing with. Yes, it's me. Yes I am not understanding.
Ok, I have absofuckinglutley had it with this !@#$%^TY&U*. I might have a broken hand from punching the garage door.

Call me stupid, call me uneducated, call me daft and anything else you can think of. I am totally effing LOST. All of these half diagrams and half thoughts in text form, make no effing sense at all. Three forums and the more I think, the worse it gets.
I know I'm the weak link here. I know it's me not understanding something. Totally my fault.
I am literally at my wits end and almost took it out on the car with a large steel pipe. I didn't, but my hand, she's not so good.

This is what I have: The diagram below. Sure, I can get the car to start and run. But these mother#ucking STA and NSW wires, make zero sense. None at all. I get it- they are supposed to prevent it from starting in anything other than P or N. FINE, I get it.
I can do nothing with them and it starts and runs just fine. I can connect them and it starts and runs. Whatever the deal is, I'm not doing it right. Yeah- it's me. Dumb it down. OVER SIMPLIFY it, please.

Somebody make this make sense, because this is what I have in my car, hanging under the dash. Pretend I'm mentally handicapped because that's what it's going to take to explain it to me. Draw in big colorful lines how the #uck this is supposed to be wired because I really am losing all patience for this thing. In a big way.
I have SEVEN wires. 7.
If you have any idea how these are supposed to go, insult me and call me retarded. Please draw in Crayola crayon so some idiot can understand them.
I have done them in every way I know how. Lost. Sorry for being a bitch, but holyshit I have had it.

 

[George_R]

Relax and forget it for a day or two. Then start digging into Wilbo's diagram. I can not draw it or explain better than he did. There's just one relay and one switch located on the trans. Any 4-pin relay has 2 pins for coil and 2 another pins for switch located inside.

Your starter relay's switch is wired as follows, one pin to +12v (constant), the other pin goes to starter

Getting to the coil. One end of it is wired constantly to ground. The other pin of the coil should be wired to "starter on" signal, which in your case is the appropriate output of your start button

Now cut the wire between the button and the relay. Wire both ends of it to the inhibitor switch located on the trans (there's no polarity). Don't mind the STA and NSW wires for now, that's too complicated for you at the moment.

If everything done properly, your car should now start only in P and N. Write back when you're done

 

[Handgrenade]

Yes sir, I was pretty mad yesterday.
I will let it sit for a day or two. Thanks guys.

 

[Handgrenade]

I have the car wired just like this and it starts in gear. I don't even care about that, it can start in gear all it wants- that doesn't bother me.
What bothers me is that damn code 42. My electronic buddy made me a voltage device that was supposed to fix the VSS code that we believe, is because I do not have the dash gauges from the donor car. His device puts out the same voltage to the ECU to try and trick it. It didn't work. But on the good news, I did connect the torque converter lock up release wire to the brake pedal and that makes a huge difference in drivability.

The next step is for me to get the dash clocks and connect them and see if that changes anything.
Currently, I'm not even using a starter relay. If you look at my hand drawn diagram= put power to the wire marked as #7, the car starts. I wired it like wilbo, and it wouldn't start at all. Because that drawing makes no sense to me. There's wires that send 12V directly to ground if you connect it like that. It's assuming more than it should. It should be a simple line drawing, like what I've drawn. Easy to follow, connect here to here. Simple.

Anyway, my car is in base map with a code 42 and an RPM code #12. It starts runs and shifts fine. Just down on power. I'll see if the clocks help. It's all down to that lame ass automatic transmission. I know it is.

Here's my book diagrams:

 

[sideshow]

I cant see how code 42 will cause yr problem
if its vvti auto then it will have sp2+-
that tells ecu speed

I recon thereis other problems

ive got a customer with a vvti and it has slight miss as u take off and when cold its not to bad but when it warms up its bad
so im sending him another ecu to try and my scanner
until u get live data out of it and drive it for awhile trying too figure what the data is telling u u wont get to far

 

[George_R]

Jim, you're really over complicating things now. As I described above, simply connecting NSW to earth in otherwise healthy LS400 is enough to get things really screwed up, including DTC42

 

[Handgrenade]

My NSW wire was not connected to ground. It never was. It is in the factory location in the ecu pin and you can trace it in the loom to the transmission plug. Same with the STA wire. I can completely disconnect them/ cut them and it's the same result. The car acts no different if they are connected or not connected. It's as if they do nothing either way.

 

[sideshow]

hey George I thought code 42 was missing speed signal from dash
that's y I sometimes put that wire to an injector
I know code 51 is sometimes a start signal problem
but on the older ecus if u had nsw to a ground it would hit a 4000 rpm limit

not sure if vvti ones do the same

hey handgrenade
I would fix code 12 first before code 42
have u done timing belt ?

 

[Handgrenade]

Yes, I have done the belt when it was out of the car.

 

[sideshow]

might be worth double checking it
I know the older 1uzs bring up code 12 or 13 if the belt is out one tooth
and the engine feels slightly under powered and retarded