Consolidated Rant: DIY4L80e Computer Swap

[KFreddy]

DIY4l80e Computer Swap is a topic that comes up time to time, this is a fresh post in response to consolidate information, the disjointed wheel and tire threads drive me insane but that's another issue altogether...

I hope this helps someone out in some way...

My trucks been parked for close to 7 months after I lost 2nd gear on the TH400, at first I was looking to rebuild the Th400 for a few hundred bucks, then I wanted more of an upgrade to handle 600+ HP then I contemplated a new HD tranny swap/ rebuild. Every thought got more and more expensive, $700 for a Yank converter alone After months of "counting sheep" at night figuring out the tranny situation as I went to sleep I found myself completely over the idea of spending a dime or my time fixing the Th400 when what I really want is a 4 speed auto, a 4l80e. I know this is different for everyone but at the end of the day I'm a damn good electrician so that someone else can be a damn good mechanic...

My Logic

5-6 years ago a HD rebuilt 4l80e was relatively cheap, reason being there was close to zero aftermarket stand alone computer knowledge, setup or support for these trannys, nor was there a huge demand for HD upgrades because of the latter. The stand alone TCU's that did exist, TCI's 1st gen TCU and the Bauman TCU were $400 to $600 and they still had their issues and needed a laptop. There are a few home brew Diesel TCU's out there however you needed a degree in "Underwater Rocket Science" just to read the code/tables never mind programming the code and tables. After a lot of maturity, and US DOD contracts, the aftermarket has caught up to the 4l80e's needs and with it the pricing has gone up for TCU's however so has the technology, usability, tune-ability and support. Check the pricing for a quality built 4l80e now close to $3000 or more, people want to be using this set up as it works really, really well.

Tranny control units and Transmissions

Computers from 2500 and 3500 Vans from 1992 to 1996 with mechanical injection and no turbo came with a separate transmission control unit. These are the computers that you want. $25.00 to $150.00

Turbo Diesel Trucks use a ECU not a standalone TCU, so there is a need to clear the upper tables and then flash and reprogram the lower tables.
'91-'92 same ECU or '93 different ECU and harness need to be used with '91-'93 transmissions and though these will all work together a non specific year will take more programming knowledge to interface. '94-'96 ECUs can be used on '94 and newer transmissions.

Reverse engineering the software/ DIY

Not to wee in anyone's cornflakes, however the wonderful thought of a cheep junk yard computer for $39.99 just doesn't pan out. If it were that simple a lot of people would be doing it this way. This is what I figured that I needed to get it done with the approximate cost. (I don't have a brother's uncle's Friend who owns a junk yard that happens to be a retired GM transmission Engineer.)

Hardware, Sensors, Schematics and Knowledge:

Laptop Computer Have one already or $250-500 on ebay
USB/ALDL-1 $85
USB/ALDL-Y cable set $120
OBDI TDF Files $50
Piggyback- chp adapter PROM/ECM $40
PROM Free to $55
TPS $25-50
VSS from a 91+ Transfer case $70
digital ratio adapter controller $80 http://www.dakotadigital.com/index.c...rod/prd126.htm
Harness Junk yard cost to $150.00
OBD-I real time scanner $250-$500 or the one you
just sold at the last garage
sale for $15
Manual locking toque converter switch
and harness or build your own. $100-$300

Wiring Diagram Free
Programming Tables Free
A switched 12V source Free

A degree in Underwater Rocket Science Priceless...

All that being said. and I'm sure I'm missing some of what is needed. your already conservatively at $700 to $900. Then to figure your time and the learning curb, the soldering and the head ache of programming dozens and dozens of lines of code though the satisfaction of accomplishing this yourself would be amazing, just make sure you have the laptop, scanner and cables if it dies on the side of the road on a road trip or a run to the grocery store...

Alternatives

If you do not mind shifting the tranny your self you could get a new valve body so you do not need a computer.

Transgo vacuum modulator Stage 3 kit $250
redrilled valve body core $100-$250 or DIY
Art Carr offers a full manual control harness $200
Painless Wiring also makes some sort of Transmission Controller though it's like $600 and the description is weak, calling tech support left the tech scratching his head and more confused then I was.

Off the shelf stand alone transmission computers

Compushift $1200 with harness, TPS and carburetor linkage, no laptop needed
TCI $750 + $150 for harness, needs laptop
GM $1100 with harness, needs laptop
PCS $1400 with harness, needs laptop -

Notwithstanding Compushift, a very good product; PCS is the # 1 reason that any TCU has made it's way into the consumer market, via SEMA show attention. Featuring in field hot swap capability laptop, TCU and correct harness are all that is needed to get just about any any electronic transmission up and running.

This list includes:
Ford AODE, 4R70, E4OD, 5R55E, 5R110
GM 4R100, 4L60E,4L65E, 4L70E, 4L80E, 4L85E, 4T40E, 4T45E, 4T60E, 4T65E,4T80E, GM 5L40/50
Mazda R4A-EL
Mitsubishi F4A3/W4A3
Nissan RE4R03A/RE4R01A
Toyota A340, U140, U340
Mercedes/Chrysler 722.6


PCS is the Granddaddy of ECU's, got a Humvee 1 or a M2 Bradley IFV, not a problem, transmission shot in that Taliban Toyota truck that was just commandeered PCS has got that covered too...

Keep in mind that both the TCI and the GM unit are made by PCS just re-badged. The PCS gives you the most control with their software the GM unit a bit less control and the TCI unit even less.

At the end of the Day well at the end of 7 months of saving and researching and saving and thinking and a little more saving I went with the GM controller and a 2010 4l85e Supermatic transmission. I figure for me it's the most complete and cost effective way to go about this, I've got enough uncharted water in my life and at the end of the day I just want to enjoy driving my truck...

Hope this rant helps someone out...