Automatic Transmissions. !!#$%*&$%!!!

[Grenade]

Ok, there is a guy that is helping me figure out why I'm getting this Code #42 over on Lextreme. He's unavailable at the moment so I thought I'd put it up here and see if anyone knows anything about the subject.

Main problem- The car starts in any gear. I also believe that has something to do with power delivery and shift points.

I am not happy. I have tried everything I can come up with based on the info I have.

Here is the diagram from the book that I'm dealing with:


It appears the STA wire along with the NSW wire, run through the auto box's PRND indicator switch. (The indicator switch is located on the side of the auto box, just above the gear selector arm) Alright, fine. I have continuity from the ECU at the correct pins for both STA and NSW. I have continuity from the ECU to the transmission indicator switch. In theory, it should be working properly. Car starts in any gear. That's not right, so I checked power to the R-L wire that feeds the switch. No power when the car is running or the ignition is in the ON position. Hmm, so I ADDED 12V to the R-L wire. No change. That was just a guess anyway.

Here is something that George the Russian showed me, it is supposed to make sense, but all it did was screw me up even more, My starter relay isn't a pass through ground like this one shows, mine is a pass through hot 12v. Check this and see if it makes sense because to me, is he talking about the starter solenoid grounding out the STA wire? No clue, makes no sense.

http://wilbo666.pbworks.com/w/page/4...ne%20ECU%20Pin

And as an additional note, I check power coming out of the ECU at the NSW and the STA wires. They both have 12V as soon as you flip the main power in the car. Straight out of the ECU, they have 12V. I hear that's not good.

I fucking hate this car. Well, not really. But when I get frustrated, it's easy to forget why I like it. I just want it to work properly. Damn hillbilly Maserati's.

[Grenade]

George said this:
"It's amazing how people get everything fkt up with only two bloody ECU pins (STA,NSW)
ok so dtc12 is gone and that's quite an achievement

Now look at your NSW pin. What you should see is 0V in P,N and 12V in any other range. If not, fix it and DTC42 must be gone

43 is trac most likely, never mind it"

[Grenade]

Yeah.

[Goldy]

On your orignial lexus diagram it appears to show that nsw and sta are connected together when in park or neutral and to whatever source that 7.5a St fuse comes from, which I'm guessing is the ignition switch? You don't need to connect it though the gear lever unless you want to maintain that functionality?

[Goldy]

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.

[Grenade]

I don't have an ignition switch. I have a main power ON. It basically powers pretty much everything, all at once. I individually switched the fuel pump for safety and the fan because I didn't have a temp sensor to kick it on and off.
If things need different voltage and at different times, it'll never be right. On, is ON.

It's not the "gear lever" on that diagram. I thought it was, but that's the selector switch inside the tranny. There's a big plug right above the arm on the side. I was mistaken in thinking all of that selector switch junk happened on the console, it happens on/in the trans itself.

[Grenade]

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.

Ok, so how can I condition the signal?
And why does it start in every gear?

[Grenade]

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 fast, has shit for power.
All other codes gone and it revs out and idles fine.

[Grenade]

I just had one guy tell me to take an injector signal and feed it to the SPD wire, it'll trick it into thinking it's got the dash cluster.

[Goldy]

So have you wired sta and now through the gear selector switch as shown in your diagram up top?

Regarding injector signal to SPD... I'm Don't do that, you will have screwed up auto shift points. The ecu is expecting to see a 5V square wave and the gearbox is kicking out a 12V sine wave from what I remember. I think you have two options... 1 find a speed sensor that puts out a 5V square wave. 2 I think some electronic jiggery-pokery may be required (schmitt opto coupler?). Maybe Paul Woods knows a simple way of getting the 5V speed signal from elsewhere?