AA80E 8-speed

[Jim Blackwood]

Guys I'm sorry to take so long getting back to this, I don't do very well at all with cold weather. But I agree with both of your comments. Here's a thought on the gear position indicator LED's though, the intermediary gears are essentially unimportant in terms of knowing which gear you are in as what is important is road speed vs engine speed, both of which are readily available via the tach and speedo. It only becomes important as you reach the top and bottom gears. So even if we blanked the display on say the two middle gears that would be no great problem. BUT, with only 3 LED outputs to the gear indicator we have enough to display 8 gear positions if we use a logic driver on the display. Cadillac does this with their shifter console gear position indicator lights and it shouldn't pose much of a difficulty to use 3 outputs to drive a 7 segment display. This would give a more sophisticated feel to the install anyway, so that's the direction I would suggest. However I will defer to your expertise.

I noticed a discrepancy, on the TCC lock-up. The standard AA80E uses lock up on the top 3 gears whereas the ISF version of the AA80E uses lock-up on all gears EXCEPT 1st gear. This is almost certainly done entirely in software and there should be no reason why we can't make use of that upgrade option. It was done that way to give the performance version a more sporting feel. I think we should allow lock up in the top 7 gears or perhaps have a user switchable choice. My version is the ISF tranny in a sporting application so I personally would like that to be the case but if that is a problem I can probably use a manual switch.

I'm waiting on warmer weather to get back on the mechanical parts of this project and there is a significant amount of fabrication yet to do, so I'd project at this point that it will be late spring to mid-summer before the job is mechanically completed. There should be plenty of time for us to iron out the control issues by then I would hope. I'll make it a point to stay on top of things better now that the holidays are behind us.

JB

[Jim Blackwood]

I'm doing some studying on the solenoid truth table, there seems an apparent discrepancy in that SL1 is energized in P, N, and 1st gear and the rest of the table looks identical. Obviously something else is up as the Transmission Power Flow table in sec. 3 (p.10) shows SL1 and SR energized, and C1 used in 1st (along with F1-sprague unit) but not in P and N. I'm not sure how it gets power in 1st and not otherwise but there must be a reason. I'll have to re-familiarize myself with the rest of it before I can make any comments on the circuit assignments but I hope to do that over the next few days. As soon as I get a chance I'm going to try to get a control cable (wiring harness) for the transmission so I can at least get started on that end of it, and I probably should bring in my MS controller and refresh my memory on it's specs, and then get a GPIO board to work with. My stinkin truck has been gobbling up all my resources though so I might not be real fast at getting all of that done but I'll get started on it.

My Lexus contact just sent me the documentation on their 5 speed automatic, model A650E so I'm going to look those files over to see how similar they are to some of the others that have been done already. Maybe it'd be simple to add that one to the list. As soon as I have something I'll start a thread on it.

JB

[Jim Blackwood]

Lance, I looked at the files for the A650E and it's control scheme seems to be very much like that of the AA80E so I'm thinking these should be useful in cross checking for errors in the files for the 8 speed. It has 2 fewer solenoids but the naming convention is identical except for one solenoid and the descriptions are extremely similar, maybe even identical in some respects. So just as soon as I can get my head clear I'm going to go back over all of these files in depth to make sure the details are right and then post my results here. I can't always do that sort of work, seems like I have a cycle I go through where I have sharp intense days ranging to befuddlement when I'm better off with simpler tasks. Shouldn't be more than a few days now and I'll be able to tackle it. Do you think it'd be good to start a A650E thread and upload the files?

JB

[Bernard Fife]

Jim,

Yes, starting a new A650E thread sounds like a good idea.

I know what you mean about some days being better than others - there are definitely days I shouldn't be allowed near a computer, much less power tools or race cars!

Lance.

[Jim Blackwood]

Thanks Lance, in a sort of perverse way I guess it's nice to not be alone. Ah well, we make the best of it. I will go ahead and start that other thread, probably a little later on today.

JB

[Jim Blackwood]

In case my last post gave the wrong impression, that really wasn't right. What I really want is for Lance to have all good days. May not be possible of course but those'd be my wishes.

How thick I've been! Now that the fog has lifted a bit it's perfectly clear that the difference from 1st gear to park and neutral is not the selection of the solenoids at all, but instead the position of the gear shift which is mechanically linked to the valve body. That should have been perfectly obvious.

JB

[Bernard Fife]

JIm,

That's the way I took it - I wish we all had more good days!

Good to know about the 1st gear and the shift solenoids. Right now the code assumes that PNR (and only PNR) are a function of the shift lever position only, but I could add a user setting to make 1st, 2nd, etc. a function of the shift lever only.

Lance.

[Jim Blackwood]

Thanks. I don't think the stock shifter ever had any provision for selecting anything other than Drive (for forward gears) unless it was then slid to the side, engaging manual mode, at which time the + - switches (and paddle switches) became active. At any rate that would be the control scheme I would adopt. Since the chart does show D1 through D8 positions one might think that those were selectable positions but I'm pretty sure the detents in the transmission allow only PRND positions. It could be that the D1-D8 positions were enabled in software through the "Mode" select switch, something we probably don't need to worry about just yet, although at some point it might be desirable on a vehicle used for towing. I will double check in a few days when I get the car back on the lift. In the meantime I will attempt to go over the solenoid assignments in more detail just to verify the chart. I think we can probably move forward with it unless there are other specifics we need to know.

I've opened my MS controller and see that the combo I have is the MS v3.0/MS-II v 3.01 (C) with heat sink mounted driver Q4 and a knock sensor circuit in the proto area using SPR3, IGBT IN, IGBT OUT, and IGN connections on the motherboard. It is set up for the Ford EDIS ignition and Ford IAC.

JB

[BupapaddyCoff]

I don't know if this has been suggested before, but is it possible to use the solenoid outputs to also drive the shift light LEDs, and leave those LED outputs for other uses?

[Bernard Fife]

pcmenten,

You can use the solenoid outputs to drive LEDs as well, the only issue is that there usually isn't a simple 1234... pattern correspondence between the gear you are in and the number of shift solenoids that are on.

If you choose not use them for gear indicators, the LEDs drivers can be used for anything that depends on being on/off in certain gears, with the appropriate components. There's more on this here: http://www.msgpio.com/manuals/mshift/V2tune.html#e and here: http://www.msgpio.com/manuals/gpo.htm

Lance.