Originally Posted by magnakansas
The vin will do nothing in my case. So no point bothering. Go bock and read through Cadillac kids redbyrd thread on his transmission swap.
There is fellow that will supply me with a new TCU, wire harness, and throttle position sensor.
In my case I will likely build/modify my own harness.
There is no input from my engine, it doesnít have electronics
let me guess jason at transmissiontuner dot com.. if so then I fully recommend him!!
this goes for the other post looking to put a 2000 series in a 94 that doesnt have the J1939..
what you will need to do is fashion up a throttle linkage to get throttle position into the transmission.. there are a few ways to do it..
if you buy a transmission, wiring harness and TCM from a newer bus as a set, it will be a "J1939" throttle, meaning its looking for throttle position from a data link.. this is what the mnid 97 and older engines lack,
CAC (custom automatic conversions) makes a throttle box in which you piggyback wire into your existing throttle pedal circuitry.. it measures the voltage and creates a J1939 data message that approximates to throttle position 0-100..
I have one of those boxes laying in a drawer.. that is the route I went on my redbyrd before I discovered my engine contained the native J1939 link (the Redbyrd TRANSformation) thread.. it did work but me being a perfectionist didnt like the operation of my transmission when running cruise control.. I had no downshifting because the pedal never moved.. it stayed in the '0' position all the time so I had to always punch the pedal on hills so kind of defeated cruise control..
the other method is a mechanical to electronic throttle box.. I believe the way Jason does it is takes a mechanical cable that is pulled in and out of a box that translates to a resistance.. his box is designed to connect to a TCM that is set up for analog or "auto" throttle .. generally this box will not work with an OEM TCM that looks for J1939 throttle only.. (he sells pre programmed TCM's as well as harnesses as well).. he may have a J1939 boix, I havent asked him for awhile..
with this type of scenerio yuo would fashion a bracket to anchor the cable housing and then a linkage you would connect physically to the arm on your pedal.. a J1939 scan tool is paramount for this as you would nbeed to see how the trans sees the throttle position as you floor and release the pedal so you can adjust your geometry (geometry is how far up or down the shank of the pedal and where to place the anchor on the dash frame) so you can achieve as close to 0 throttle off pedal and 100% throttle reading to the trans when floored..
this method also will give you lackluster results running cruise control as the pedal is always at 0% even when climbing hills and the engine is working its arse off..
the next method is to do it all electronically with either a commercially sourced J1708 to J1939 converter or you can build your own..
even the 1994 T444E engines have J1708 (its whats on the 6 pin gray connector under the dash).. in this data stream are several data points of note..
1. TPS - threottle position. 0-100% of actual pedal position
2. Engine Load - an approximation of the engine's load factor 0 - 100%
3. Cruise Set speed. when cruise is active shows as the set.. or 0 if cruise is off
4. Cruise Active. shows as engaged or disengaged..
these parameters also exist in J1939 as well...
using a translator you can run an OEM J1939 allison TCM (like would be on a modern bus).. and you can translate the data from your J1708 into J1939 parameters and send them to the transmission.. sometimes when cruise is engaged you can simply send the engine load factor in place of the actual pedal position.. modern TCM's recognize that cruise is on (since you tell it thats the case).. this method is the hardest if you dont know how to write code, but is the easiest if you do..
you use a pair of these devices..
and then run the data through a raspberry pi or such and write a program to make the data translations.. I think there is some coding stuff in my redbyrd trans thread...
I have a few of those advantech devices (their earlier versions) and they work well...
you could also build your interfaces using ELM325 (J170
and ELM327(J1939) chips and roll your own raspberry pi hat...
since i write code for everything from my work stuff to my home HVAC to my busses.. it seems like a rather easy method..
just some things to think about..