Electronic tranny controllers...4L80e

I did a search on tranny controllers....and was not getting anything but super high prices and little else but so they make it seem like a rare find...

parameters are a Qjet 350 engine in a van camper....

and so with a 411 rear it needs a overdrive...but the only one capable of standing the load is a 4L80e

so to find a REASONABLY priced controller....

then to find out just HOW, exactly it controls....

can anyone get me a wiring diagram?? and a function chart??

or a source that don't want 600+ bux for a simple controller 'computer'>???


:friends:

Sorry Gene, I don't think there is one...

I maybe have to make one then....it's gotta be simple to do....

I suppose a MAP sensor off a TPI and a engine rpm sensor...make that a voltage taken off the tach.....

and I suppose there is some sort of vehicle speed sensor input too....

then I presume 6 wires into the tranny....1-2-3-4 gears and lockup.....and a +12 source for the lockup solenoid if nothing else....

so a simple op amp and some voltage comparators so switch at whatever is needed, saturate some transistor to pull shift lines up or down.....

BUT I have never seen a print of any wiring for one of them....

anyone have something??

:shocking:

In addition to the parameters you mentioned, there is also a line pressure solenoid- that one will be the tough one. It has to stay proportional to the road speed and the selected gear- no sense running 200 PSI all the time and working the pump to death, not to mention the added heat.

TimAT said:

In addition to the parameters you mentioned, there is also a line pressure solenoid- that one will be the tough one. It has to stay proportional to the road speed and the selected gear- no sense running 200 PSI all the time and working the pump to death, not to mention the added heat.

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Tim has some very good points.
I've designed PCMs for other electronically controlled tranmissions (I don't have any personal experience with the 4L80E), and there's a variable PWM circuit in the PCM that modulates the position of a line pressure solenoid (modulating the pressure). This solenoid control circuit obviously controls an inductance, meaning keeping track of the solenoid current, and properly allowing current recirculation (and flyback voltage clamping) during the time that the driver transistors are turning on and off. Simple in principle, but just a lot of parts sizing and timing issues to deal with.

Thanks anyway, guys, too much PIA to fiddle with, like most aftermarket computer/car crap....better off with factory setup....certainly cheeper....

so am going late 700r4, as TimAT said he will help rebuild one....I got a 4L60e and a '91-92 700 truck core a couple days ago, so tore the 700 apart....going to talk to Tim about it, and go from there, have to pay property taxes on what is supposedly MY house, and so maybe sometime in Feb before I can get the parts.....

:twitch::skeptic:

mrvette said:

Thanks anyway, guys, too much PIA to fiddle with, like most aftermarket computer/car crap....better off with factory setup....certainly cheeper....

so am going late 700r4, as TimAT said he will help rebuild one....I got a 4L60e and a '91-92 700 truck core a couple days ago, so tore the 700 apart....going to talk to Tim about it, and go from there, have to pay property taxes on what is supposedly MY house, and so maybe sometime in Feb before I can get the parts.....

:twitch::skeptic:

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Yeah, that has always rubbed me the wrong way. I feel less like I own my house, and more like I'm just renting it from the county. If I don't pay that bill on a regular basis, I'll get tossed out on my ass.

On that same subject, is there a cheap, simple electronic manual controller for an electronic trans? Like something that could be used with paddle shifters?
Sorry, I dont know enough about electronic transmissions...but if it's simply applying voltage to the correct solenoid(s) without having to monitor engine load, rpm, etc, that could be done cheaply.

Garys 68 said:

On that same subject, is there a cheap, simple electronic manual controller for an electronic trans? Like something that could be used with paddle shifters?
Sorry, I dont know enough about electronic transmissions...but if it's simply applying voltage to the correct solenoid(s) without having to monitor engine load, rpm, etc, that could be done cheaply.

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Yeh, that's what I thought too, but when thinking about it, they all have some rpm/tposition lever or vac modulator, or both.....

too much like high probability of burning the damn thing up while testing/experimenting....on route with the 700 now,

:noworry:

I thought they made a manual valve body for the 4l80e now. I used a PCS controller for mine. Works great!

wickd said:

I thought they made a manual valve body for the 4l80e now. I used a PCS controller for mine. Works great!

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Welcome to the motley crew of the Flying Dutchmen....


I never heard of the manual VBody, dunno, but would be scared of the cost, this whole thing is a budget build....bad enough with the 700 but to be tossing something over a grand for overdrive is a bit much....

:crutches:

I think what you are looking for is a trans controller for a 95 6.5L diesel. Reason being that is the only year that GM had a 4L80 behind a mechanical pump diesel. Don't know what it would take to get it to work in your van though.