Chrysler 41te Trans Control

A forum for discussing applications and implementations of the MegaShift transmission controller code for the GPIO from B&G. This can control up to 8-speeds and 6 shift solenoids (plus a 16x9 table for controlling a PWM line pressure valve). It has manual and fully automatic modes (16x9 load x speed table), with under and over rev-limit protection, and full data logging of all inputs and outputs (among many other abilities). A TransStim to test your completed board is also available.
UnaClocker
Posts: 14
Joined: Tue Oct 13, 2009 2:34 pm

Re: Chrysler 41te Trans Control

Post by UnaClocker »

racerstev wrote:No no, the factory cruise control switch's are multiplexed and all use one wire to the PCM. Say when you hit the "set" button you get 3.3 volts, when the
trans controller see's 3.3 volts it is set to upshift. The Reset button on the steering wheel might give 1.1 volts, set the controller to read 1.1 as a
downshift.

When in manual mode you would need to turn off the cruise control to make it work, just a relay on the power wire or something. When in Auto mode
the cruise control can go back to normal.

Steve
This would also be VERY handy for people wanting to use their horn wire on older cars.. (Might even be able to run the horn through a spare output on the GPIO or the MS itself when it sees the horn value over CAN).. :shock:
racerstev
Posts: 19
Joined: Thu Jan 15, 2009 2:46 pm

Re: Chrysler 41te Trans Control

Post by racerstev »

Can anyone tell me how to get the 4th PWM output working? It's setup for pressure control but
we need it as a solenoid driver. Other then that it looks like this will work.

Steve
tjabo
Posts: 68
Joined: Mon Jan 12, 2009 10:40 am

Re: Chrysler 41te Trans Control

Post by tjabo »

Steve, does this mean you've been playing with the .ini file for MShift in TunerStudio or MegaTune? If so, I guess it's looking promising!

Have you looked back through this thread to see if this question may have been addressed? I was kind of thinking I saw an answer to your question within this thread somewhere when I did my last re-read of it. . . Time for me to re-read it again I guess! :?

I know one reason I may need to re-read it is that a lot of the discussion in the thread (especially early) related to how to run the MShift without being able to pull from the CAN bus in case you decided not to run MS2. Since you are, some of those matters are definitely simplified. Now all we need to do (I think) is figure out whether we can get away with one fewer inputs for the range sensor stuff, and then get this PWM output configured, and I think we're rolling! Does that sound right to you? (again though, I really need to do another re-read--this thread has a lot of good reference material in it)

Thad
Turbo Neon, converting to 41te trans sometime?
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Chrysler 41te Trans Control

Post by Bernard Fife »

Can anyone tell me how to get the 4th PWM output working? It's setup for pressure control but
we need it as a solenoid driver.
Steve,

I am not sure what you mean. The pressure control output in the code *IS* designed for PWMing a solenoid that bleeds the pressure to control the line pressure. So it can be used to drive a solenoid with PWM and will give PWM% according to the user settings and table. If you need it ON/OFF rather than PWM, you just put zeros and 100s in the table as required.

Maybe I am not understanding something?

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
tjabo
Posts: 68
Joined: Mon Jan 12, 2009 10:40 am

Re: Chrysler 41te Trans Control

Post by tjabo »

Hey guys,

I've finally opened up a MegaShift project in TunerStudio, and it looks GREAT! ! ! ! Beautiful work Lance!

So now the next phase of the work begins to start figuring out how to configure everything the way we will need it for this trans, and along the way figure out what hardware changes we might need on the board. I'm going to help Steve get setup on TS if he has still been using MegaTune, since I think it's easier to switch between projects (MS2 to MShift) on TS.

But Lance, if you could, would you be willing to give me/us some beginning pointers on which outputs we might need to configure to get our numerous inputs from the range sensor, and our numerous outputs to our solenoids (including our "extra" one) configured?

Thanks!

Thad
Turbo Neon, converting to 41te trans sometime?
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Chrysler 41te Trans Control

Post by Bernard Fife »

Thad,

Most of the user-configurable settings are described here: http://www.msgpio.com/manuals/mshift/4L60E_MT.html. I haven't checked to make sure that absolutely all of the latest settings are there, but I will do that soon.

Because I'm not familiar with your trans, I can't be a lot of direct help, but I can say that the defaults in the code are for:
- digital shift lever positioning (configured for a 4L60E),
- PWM pressure control,
- 3 solenoid shifter outputs (set up for a 4L60E, but the patterns, and PWM settings where used, are user configurable if required),
- 1 spare ADC (variable voltage) input, plus one more if CAN is used to get the load, plus more if a 'Ford' style variable voltage shift scheme is used,
- 2 spare outputs with PWM (these can be switched by gear or speed or rpm or load).

To see how these are used in the default "4L60E" configuration, look at this: http://www.msgpio.com/manuals/mshift/wiring.html

If there's anything that doesn't make sense or you can't find, just ask and I will try to help.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
tjabo
Posts: 68
Joined: Mon Jan 12, 2009 10:40 am

Re: Chrysler 41te Trans Control

Post by tjabo »

Thanks Lance,

I'll try to give that a good looking over in the next day or two, and then spend some more time with the settings in the TS project now that I have that setup. After that I'll see if there are any semi-intelligent questions I have! :D Hopefully Steve will be able to get going with the TS soon too, since he is intimately familiar with these transmissions, and the settings needed to operate them.

Thanks again for the help!

Thad
Turbo Neon, converting to 41te trans sometime?
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Chrysler 41te Trans Control

Post by Bernard Fife »

Sounds good, let me know how I can help. Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
UnaClocker
Posts: 14
Joined: Tue Oct 13, 2009 2:34 pm

Re: Chrysler 41te Trans Control

Post by UnaClocker »

UnaClocker wrote:Something I wanted to contribute to this thread.. The range selector.. It's simply 4 on-off switches.. It was mentioned that that's kind of a waste of inputs on the GPIO.. Why not multiplex them all into one wire? Put a different resistor value on the output of each switch.. Little bit of math in the code could quickly determine which switches are on to get the current voltage reading.. Chrysler does this ALL OVER the place inside their modern cars with the BCM.. Then you'd only need one ADC input to the range selector.. No other inputs wasted.
Lance wrote:UnaClocker,

If you do it that way, you save inputs, as you say. The code already allows user-settable variable voltage inputs for determining the shift lever position, and when this is selected (over multiple digital switches) the remaining inputs become general purpose ADC inputs that can be logged, etc. So it's a very good idea you have!

Lance.
Ok, I'm in the process of assembling my GPIO and I'm looking into doing this now. I had forgotten Lance said that the code already supports what I want to do. That's great. As mentioned in this thread, and documented on the 41te WIKI, this trans has 4 on-off switches, one side tied to ground. They are "T42, T41, T3, and T1" and in that order, I plan to install a resistor on each, 500ohm, 750ohm, 1000ohm, and 2200ohm before the all join into the single input. I figure a 1k pullup on that input?
Using those resistors, you'd get these resistance values:
Park - 230.77 ohms
Reverse - 500 ohms
Neuteral - 264 ohms
4th - 2200 ohms
3rd - 1000 ohms
2nd - 289 ohms
1st - 523.81 ohms


As long as 230, 264 and 289 are far enough apart to get clearly different ADC #'s, I think this is going to work out great.
tjabo
Posts: 68
Joined: Mon Jan 12, 2009 10:40 am

Re: Chrysler 41te Trans Control

Post by tjabo »

Any more thoughts on this "multiplexing the shifter inputs(s) idea? Assuming there even are enough inputs for the 41te shifter, it would be nice to save them for other things like this. . . .
Turbo Neon, converting to 41te trans sometime?
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