Memory dump of ECU

[b3lha]

Originally Posted by Nomake Wan

And now, the results!

HOLY CRAP, MOST AWESOME PROGRAM EVER. You should've seen my grin as I drove around with the thing running. It's amazing how your programs seem to pull off what a certain other program can't--namely polling multiple variables all at once and returning accurate information 100% of the time in nearly real-time speed.

I'm glad you like it.

Originally Posted by Nomake Wan

Turns out, the only time I could get Solenoid C into 95% (FWD I'm guessing) was if I put the shifter into N or P. As soon as I put it into drive, I'd usually get about 60%-70%. Drop it into 1st and that lowers to 45% or so.

I did manage to drop it to 5% once, when I mashed the gas from a dead stop. That was fun too.

Maybe one of the mechanical guys can chime in here on how the duty cycles relate to the torque split?

Originally Posted by Nomake Wan

After the whole test drive was done, I did notice that a second percentage appeared next to Solenoid C's duty percentage. 27%. What's that about? Glitch? It didn't change at all after I messed around sitting in the driveway... hm.

Yeah. Sounds like a bug in the program. There's quite a few things that I need to fix up.

It's a pretty simple program. Just three steps repeated over and over: read value, decode value, display result. All the hard work talking to the TCU is handled by the ssm library functions. Could very easily be modified to pull in ECU data as a less pretty alternative to Kevin's program.

Originally Posted by Nomake Wan

My only suggestion is that you add in an indicator for the Torque Converter Lockup. I'll test it the next time I hit the freeway.

I thought solenoid B controlled the torque converter, but I'm not 100% sure. On my car DutyB seems to stay at 5% unless I'm in 4th with power mode off. Can somebody explain how this works?

[b3lha]

Actually I have another question about the workings of the transmission. Do the shift solenoids do anything when the car is in reverse? I always thought that reverse was 1st gear run through an extra cog to change the direction.

But I noticed that, on my car, clicking the manual button changes the state of solenoids 1 & 2 from "1st gear" to "2nd gear" even when the stick is in reverse.

[svxistentialist]

Originally Posted by b3lha

Actually I have another question about the workings of the transmission. Do the shift solenoids do anything when the car is in reverse? I always thought that reverse was 1st gear run through an extra cog to change the direction.

But I noticed that, on my car, clicking the manual button changes the state of solenoids 1 & 2 from "1st gear" to "2nd gear" even when the stick is in reverse.

Phil, I'm not an expert on the workings of the box, but your supposition is incorrect anyway. Reverse is not actually 1 range going the opposite direction.

The ratio for 1 range is 2.785, that for reverse is not quite so low at 2.272. Effectively they are different cogs.

I would expect the Manual button to behave as you describe; as MANU has no effect on reverse [reverse is not as low as 1st, so will be less likely to spin the wheels], what is happening when you engage Manual will be pre-selection of 2 range for forward travel only.

So if you are "rocking" the car between forward and reverse with Manual lit up to get it out of a sticky spot, you will be changing between reverse and 2 range, rather than reverse and the lower, more wheel-spinning 1 range.

At least that's how I would imagine it is set up.

Joe

[Nomake Wan]

Originally Posted by b3lha

It's a pretty simple program. Just three steps repeated over and over: read value, decode value, display result. All the hard work talking to the TCU is handled by the ssm library functions. Could very easily be modified to pull in ECU data as a less pretty alternative to Kevin's program.

Please do! I'd love to test that out...but I guess I gotta build that correction board to test it...

Originally Posted by b3lha

I thought solenoid B controlled the torque converter, but I'm not 100% sure. On my car DutyB seems to stay at 5% unless I'm in 4th with power mode off. Can somebody explain how this works?

Well, I'm not sure how it works... but if so, you could even have an indicator that's something like "IF SolB = n% THEN display_LockupIndicator" or whatever. I dunno, it just came to mind as I was driving back home from the first test drive.

[b3lha]

Originally Posted by svxistentialist

Phil, I'm not an expert on the workings of the box, but your supposition is incorrect anyway. Reverse is not actually 1 range going the opposite direction.

The ratio for 1 range is 2.785, that for reverse is not quite so low at 2.272. Effectively they are different cogs.

The ratio would not be the same as 1st because it would depend on the number of teeth on the reverse cog. But as you say, my supposition was most likely incorrect. Things I have read about old 4MT boxes almost certainly don't apply to the 4EAT.

[b3lha]

Originally Posted by Nomake Wan

Well, I'm not sure how it works... but if so, you could even have an indicator that's something like "IF SolB = n% THEN display_LockupIndicator" or whatever. I dunno, it just came to mind as I was driving back home from the first test drive.

Yeah that would work. Something like:

if (DutyB < x)
{
    display "unlocked"
}
else
{
    if (DutyB < y)
    {
        display "locking"
    }
    else
    {
        display "locked"
    }
}

Provided that somebody says Solenoid B is the right one and we can figure out the values for x and y.

[Nomake Wan]

Originally Posted by b3lha

Yeah that would work. Something like:

if (DutyB < x)
{
    display "unlocked"
}
else
{
    if (DutyB < y)
    {
        display "locking"
    }
    else
    {
        display "locked"
    }
}

Provided that somebody says Solenoid B is the right one and we can figure out the values for x and y.

If solenoid B is the one, I'll try hitting the freeway later just to see what % it's at when locked. Interesting that there's no "locked" signal, though.

[oab_au]

Originally Posted by b3lha

Actually I have another question about the workings of the transmission. Do the shift solenoids do anything when the car is in reverse? I always thought that reverse was 1st gear run through an extra cog to change the direction.

But I noticed that, on my car, clicking the manual button changes the state of solenoids 1 & 2 from "1st gear" to "2nd gear" even when the stick is in reverse.

Hi Phil n all, there are two sets of solenoids in the box, Solenoids A, B, C control the effect of Line pressure, AWD pressure and converter lock up operation. Solenoids 1,2,3, control gear selection. The A, B, C solenoids are modulated with a PWM Duty Cycle. Solenoids 1,2,3, are just turn on or off. Not modulated.

The way the solenoids operate the box is like this. First and Reverse are both selected by the Shift lever operating the Manual valve, the No.1 and No.2 shift solenoids don’t really play a part in First or Reverse, they are electrically turned on, but just bleed off pressure. The shift solenoids 1,2 then turned off in turn to control the selection of 2,3,4. The No.3 shift solenoid turns the over-run clutch on to give engine braking, and used to smooth the 3rd to 2nd change.

The A, B, C, solenoids are modulated to control oil pressure. The A controls the Line pressure, and varies between 5% (full line pressure) and 95% (low line pressure). The C solenoid operates the AWD. For the Transfer system, 5% is fully applied clutch, 95% is a free clutch. For the VTD AWD 5% is free clutch, 95% is a locked clutch. The B solenoid operates the converter lock-up clutch, it is not varied as much as A or C solenoids, it is just turned on or off, but the turned on, is modulated, to reduce shock.

Harvey.

[svxistentialist]

So Harvey, are you saying that the shift lever manually operates a valve that selects either first or reverse, depending on position?

And does this imply that Phil is correct, first and reverse are using the one gear shaft, just turning in a different direction based on the position of the selector?

Joe

[oab_au]

Originally Posted by svxistentialist

So Harvey, are you saying that the shift lever manually operates a valve that selects either first or reverse, depending on position?

And does this imply that Phil is correct, first and reverse are using the one gear shaft, just turning in a different direction based on the position of the selector?

Joe

Yes and no Joe.
The shift lever selects first and reverse manually.

As to how the two ratios are achieved. not like a manual box, not different cogs.
There are two planetary gear sets, that are always engaged. There are three elements toq each set, Sun gear, Planet gears and Ring gear.
The drive is applied to one of these elements, the output is taken form one of the others, and we use a clutch or brake to hold the third element still, to achieve the ratios.

Harvey.

[Trevor]

As a result of this post I will no doubt again be accused making an attack, but so be it. Incorrect information is not in the interests of members and requires correction. This particularly applies in respect of the arduous work covered by this thread.

First and Reverse are both selected by the Shift lever operating the Manual valve, the No. 1 and No. 2 shift solenoids don’t really play a part in First or Reverse, they are electrically turned on, but just bleed off pressure.

Solenoid valves 1, 2, & 3 are normally open devices and close and shut off fluid when energised (electrically turned on). In this state they do not bleed off pressure and close the bleed so that pressure is applied.

The shift solenoids 1,2 then turned off in turn to control the selection of 2,3,4.

These normally open solenoid valves are turned ON in order stop pressure bleed off and as a result then provide control pressure in respect of the selection of ratios 2, 3, & 4.

The C solenoid operates the AWD. For the Transfer system, 5% is fully applied clutch, 95% is a free clutch. For the VTD AWD 5% is free clutch, 95% is a locked clutch. The B solenoid operates the converter lock-up clutch, it is not varied as much as A or C solenoids, it is just turned on or off, but the turned on, is modulated, to reduce shock.

Solenoid valves A, B, & C, in the case of transmissions incorporating a centre clutch, are all normally closed devices. Solenoid valve C is a normally open device in the case of transmissions incorporating a centre differential.

Thus in both systems the respective C Solenoid valve is near fully energised for virtual lock up of front rear, without requiring a different configuration of electrical or hydraulic systems. Both C valves bleed off fluid as a means of control.

Cheers, Trevor.

[Trevor]

Greetings Joe,

Your confusion is understandable.

The range selector lever holds the range/extent of progressive gear selection, rather than selecting low or any individual gear. As you well know, unless manual is selected, the transmission will start out in low and then move in progression as far as the ratio chosen, e.g. third speed for city use.

When set in first the lever sets the inhibitor switch which transmits a range signal to the TCU, whereby solenoids 1 & 2 are energised and the ratio is held. The operation involves both manual lever movement and electrical signals.

Cheers, Trevor.

[b3lha]

Originally Posted by oab_au

Hi Phil n all, there are two sets of solenoids in the box, Solenoids A, B, C control the effect of Line pressure, AWD pressure and converter lock up operation. Solenoids 1,2,3, control gear selection. The A, B, C solenoids are modulated with a PWM Duty Cycle. Solenoids 1,2,3, are just turn on or off. Not modulated.

The way the solenoids operate the box is like this. First and Reverse are both selected by the Shift lever operating the Manual valve, the No.1 and No.2 shift solenoids don’t really play a part in First or Reverse, they are electrically turned on, but just bleed off pressure. The shift solenoids 1,2 then turned off in turn to control the selection of 2,3,4. The No.3 shift solenoid turns the over-run clutch on to give engine braking, and used to smooth the 3rd to 2nd change.

The A, B, C, solenoids are modulated to control oil pressure. The A controls the Line pressure, and varies between 5% (full line pressure) and 95% (low line pressure). The C solenoid operates the AWD. For the Transfer system, 5% is fully applied clutch, 95% is a free clutch. For the VTD AWD 5% is free clutch, 95% is a locked clutch. The B solenoid operates the converter lock-up clutch, it is not varied as much as A or C solenoids, it is just turned on or off, but the turned on, is modulated, to reduce shock.

Harvey.

Thanks Harvey,
That's useful information.

[Nomake Wan]

Okay, just went on another run. Unfortunately, during this run my wiring to the TCU for POWER mode seems to have fallen apart (though I've checked it and it seems to be correct, so I'm not sure why it isn't registering power mode anymore). I'll have to redo it tomorrow, but until then, it's back to normal USDM economy mode...

Anyway, some observations from this run.

1.) Those weird secondary percentage indicators appear on all three of the Duty Solenoids. Bug in the GUI.

2.) Duty Solenoid B remains at 5% when unlocked. When the torque converter locks, the solenoid jumps to 50% and then transitions from 50% to 95% gradually. If the transmission is in "Normal" mode when you disengage the cruise control, it drops to 55%, but does not go down to 5%. So when driving around without Power Mode, the torque converter appears to be in a semi-locked state. Odd. It'll go down to 5% if you start to brake for a stop, though. Presumably to prepare for sudden acceleration.

3.) Duty Solenoid C is at 65% about 95% of the time when driving around normally. So whatever 65% represents torque-split wise, that's what the USDM cars maintain. Power or Normal mode doesn't make a difference. Also, as before, the only time that Duty Solenoid C went to 95% was when the shifter was in P or N. The most I've ever seen it at while driving was 70%. And the lowest of course was 5% when launching from a stop.

4.) Duty Solenoid A remains at about 58% most of the time when just cruising, and alters based on a direct relation to throttle input.

I also took a better screenshot... I'm a sucker for clarity.



Hope this helps some!

[Trevor]

Nomake,

Your observations add up and as you will see tie in with my explanation regarding solenoid operation.