Pre-1998 T444E Transmission Options

[j2d2-SKO]

Hi folks,

I've been lurking a while here and a few other places like pirate 4x4 looking for possible transmission options. I've got a '98 Thomas 3800, which unfortunately was built on a '97 chassis - so I'm a year off from having J1939 support from the ECM.

My current plan is to throw a cooler on the 545 and run it until it blows. But I'm trying to plan out what will go in there when that happens.

Obviously I could attempt a 643(with great difficulty) or a Spicer 5-speed. But I'm curious if anyone knows options for the MD3060 or the A-2000.

I've found conflicting reports on the 3060 - some saying it requires J1939, and others indicating there were TCMs that ran off J1708. So far I've seen J1939 and "AUTODETECT" stamped TCMs for sale and I'm not positive what that autodetect means.

I'm also curious if anyone has experience with the J1708 -> J1939 converters:

https://c-a-i.net/translators/j08
https://copperhilltech.com/mastercan-v-gate-sae-j1939-sae-j1708-to-sae-j1939-gateway/

Looking at the documentation - they convert throttle position, engine load, road speed, etc messages. I can't think of much else the transmission might need - so I'm curious if anyone has experience there. I can't imagine the transmission NEEDS the faster baud rate of J1939.

 

[magnakansas]

my example

2007 2400pts

there is an engine rpm sensor in the transmission -- it looks at the torque converter rpm.

drive shaft rpm sensor is at the tail of the transmission... I assume the TCM programming has stuff like rear end gear ratio and some thing to do with tire sizes

To me it looks like there is a third rpm sensor in the middle of the transmission.. I assume it has something to do with being able to see if the transmission is shifting gears.........

My engine is a mechanical injected cummins -- there are no electronics to interface with.

The mechanical injection cummins 8.3 is found with the 3060 and that had no electronics.... so from talking with Jason at transmission tuners.....

I will have to wire in some parts from a harness... He preferred to use a new TCM. So, there is the ability to use this transmission with an engine that is all mechanical.

CadillacKid is the fellow that forged the path for people like us here on the forum. I am just following along his path.

william

william

 

[cadillackid]

the AutoDetect TCM is your best bet, or you can get a throttle box from CAC (or i believe jason at transmissiontuner dot com)..


the box I originally got from CAC (and still have in a drawer).. took the voltage reading from my drive-by-wire pedal and converts it to J1939..



that was what I used before I enabled and connected my J1939 link, it didnt affect my normal drive-by-wire operation.



the other method you could go is to forge your own mechanical cable-pull and use a mechanical-to-J1939 throttle box. sold by CAC and Jason also I believe... these equate an amount of cable pulled from the box to a J1939 throttle reading...



I havent used a J1708 to J1939 converter although as long as it sends throttle data it would be an option.. I built one but cant remember what I was going to use it for..



supposedly the WTEC-II TCMs were built to use J1708 as the throttle input.. at least some of them.. many of them used an analog throttle (a TPS sensor that sent a return voltage based on position).. I have next to no experience with WTEC-II stuff so i havent tested..



this is one of CAC TPS units for mechanical use..



https://www.caconversions.com/cac-throttle-position-sensor


they also make an electronic version.. the one I have and had connected to my 444E prior..



the all analog throttle and auto-detect TCM are often CAT throttles.. as caterpillar was the first to install electronic transmissions on the electronic engines.. the 8.3 was a favorite to get the 3000 series and the 3116 / 3208 saw a few as well..



if you are going 6 speed 1000/2000, then I doubt you'll find many TCMs that are auto detect. most will be J1939..



again I have ended up forgin my own path to get to my beautifully shifting and responding set up.. everything from engine mods to trans tuning, boards, etc..



when thinking about how this stuff works, cruise control is another issue altogether.. as the pedal stays at 0% when on cruise in a T444E.. which can create a host of issues from no downshifting to shifting in a non modulated state.. this is why I went J1939 and enhanced the data stream to feed the TCM as much cruise info as i could, if you dont use the cruise control then its probably a noin issue for you.

 

[j2d2-SKO]

Thanks for all the info folks. Sorry it's been a sec - been away for work for quite a while.

Found some interesting reading here from folks reversing the GM TCMs (taking a PWM TPS input instead of j1939) https://www.4btswaps.com/threads/th...0-2000-2400-info-and-swap-guide-thread.15428/

Curious what kind of j1939 cruise data you're able to send to the transmission for cruise?(I haven't bought the spec yet and haven't found a free download, so don't have the full list of messages)

I'd been contemplating cruise control too and thinking about having a MITM unit between the TPS and the transmission (isolated from the TPS signal heading to the engine for safety) that would use the J1708 Engine Load message as a proxy for throttle position whenever cruise is on. And hope that it gives stable results.

 

[cadillackid]

Thanks for all the info folks. Sorry it's been a sec - been away for work for quite a while.

Found some interesting reading here from folks reversing the GM TCMs (taking a PWM TPS input instead of j1939) https://www.4btswaps.com/threads/th...0-2000-2400-info-and-swap-guide-thread.15428/

Curious what kind of j1939 cruise data you're able to send to the transmission for cruise?(I haven't bought the spec yet and haven't found a free download, so don't have the full list of messages)

I'd been contemplating that and thinking about having a MITM unit between the TPS and the transmission (isolated from the TPS signal heading to the engine for safety) that would use the J1708 Engine Load message as a proxy for throttle position whenever cruise is on. And hope that it gives stable results.

yep ive done it.. ive build a MITM J1939 box to manipulate the parameters going to my allison... I have not played with actual throttle control via a box but im sure i could do it.. I did set the high idle by becoming the module ID for an auxilliary throttle control such as an RE bus would have and sending a setpoint... but never on the road.. i have no need and could cause real issues..



anyway i cant remember the PGN / SPN numbers for the cruise data, however the ECM sends to the TCM that cruise is engaged and sends the setpoint data.. the TPS signal for the trans directly matches the engine load factor... the other paranmeter that gets sent which the allison responds to much quicker is a kickdown request which drops the transmission down a gear.. this request gets released to 0 when the overload factor is cleared down.. seems to be load factors less than 75% or so..



depending on your TCM you can also emulate module ID 5 which is the allison standard for a digtal shift-pad and then you can up/down shift at will and set your maximum gear range..



manipulating the throttle data to the trans wont hurt.. it wont downshift into a dangerous gear as the TCM has a maximum RPM..



on my tuneable TCMs that RPM is programmable by me... non tunable TCMs that RPM is factory set and stamped on the TCM..


someplace in one of my threads i talked about reading and parsing J1939 data and code I played with..



I have the spec but its too big to upload to the bard so ive never sent it here

 

[Bouje bus]

@j2d2 did you end up swapping out your transmission?

Curious if you went the route of a j1708 to 1939 converter?



I am in the same bus (sorry bad joke) my 1998 amtran has a 1997 build t444e. I'm looking at options to convert the older signal.

This company seems to offer more info than some of the others I've found


https://www.auelectronics.com/System-GW2-1708-1939.htm

 

[nikitis]

@j2d2 did you end up swapping out your transmission?

Curious if you went the route of a j1708 to 1939 converter?



I am in the same bus (sorry bad joke) my 1998 amtran has a 1997 build t444e. I'm looking at options to convert the older signal.

This company seems to offer more info than some of the others I've found


https://www.auelectronics.com/System-GW2-1708-1939.htm

I'm in this boat as well. I will run my 545 till it grenades, but I want to eventually upgrade it. Would be nice to throw a 6 speed in here. 3box 1995 T444E with J1708 only. (Built in 1994 so first model).

If you figure this out and DIY, please take pictures and document the process. There's a few of us who'd like to do this ourselves but have no idea where to start.

This device does seem to be a J1708 to J1939 CAN network gateway, and converts certain items listed in the chart. Can you review the chart @Cadilackid and let us know if the chart has all of the converted values a transmission/ECM would require? I would think if the values converted are all the transmissions needs then we just need a medium to plug in the modern Allison TCM into it and I'm not sure if you can just simply plug a TCM into that GW2 device, it seems it may require an additional device between GW2 and the TCM as it's just a gateway device.

It does claim to translate the following bi-directionally:
J1708 J1939
(Excuse the double listing, it's listing J1708 name and then the J1939 name)
1 Road Speed Wheel-Based Vehicle Speed
2 Total Vehicle Distance Total Vehicle Distance
3 Total Engine Hours Engine Hour
4 Engine Speed Engine Speed
5 Engine Coolant Temperature Engine Coolant Temperature
6 Engine Oil Pressure Engine Oil Pressure
7 Boost Pressure Engine Turbocharger Boost Pressure
8 Cruise Control Set Speed Cruise Control Set Speed
9 Percent Accelerator Pedal Position Accelerator Pedal Position 1
10 Percent Engine Load Engine Percent Load At Current Speed
11 Intake Manifold Temperature Engine Intake Manifold 1 Temperature
12 Barometric Pressure Barometric Pressure
13 Battery Potential(Voltage)) Battery Potential / Power Input 1
14 Fuel Temperature Engine Fuel Temperature
15 Engine Oil Temperature Engine Oil Temperature 1
16 Fuel Rate (Instantaneous) Engine Fuel Rate
17 Instantaneous Fuel Economy Engine Instantaneous Fuel Economy
18 Average Fuel Economy Engine Average Fuel Economy
19 Power Takeoff Set Speed Power Takeoff Set Speed
20 Road Speed Limit Status Road Speed Limit Status
21 Cruise Control Status Cruise Control Status
22 Power Takeoff Status Engine PTO Governor Accelerate Switch
23 Idle Shutdown Timer Status Engine Idle Shutdown Timer State
24 Engine Retarder Status Retarder Enable - Brake Assist Switch

 

[cadillackid]

that device is one ive looked at online in the past but never boght one.. it looks like it would translate enough PID's for the allison to work.. throttle being the most important.. the cruise downshift control probably wont work right unless it sends the cruise infp in such a way allison understands it...



looks like they will sell to the US...

 

[Bouje bus]

I reached out to the vendor and they were very responsive. I went for it and ordered the version with the resistor to create the 120 ohm loop, thinking that is what the TCM will be looking for. Within an hour I had shipping information. I'll take pics and document what I find when it arrives from Canada.

 

[nikitis]

I reached out to the vendor and they were very responsive. I went for it and ordered the version with the resistor to create the 120 ohm loop, thinking that is what the TCM will be looking for. Within an hour I had shipping information. I'll take pics and document what I find when it arrives from Canada.

I'm cheering you on, and please do send pics and instructions. Did he say it required anything else or can you just pop your TCM straight into that thing, and that thing into where the TCM would normally plug into?

 

[cadillackid]

I'm cheering you on, and please do send pics and instructions. Did he say it required anything else or can you just pop your TCM straight into that thing, and that thing into where the TCM would normally plug into?

this is custom building, there is rarely "pop this into your TCM"..


most likely it will need a little programming so it can view the J1708 data, and be set as the Module ID of an ECM on the J1939 side.



the pinouts are on the site and so you will need to use twisted pair wire to connect it up.. theoretically it will be a minimal amount of setup and will just work..



to power it , it appears to take a wide range of power.. my experience with datalink type devices is you will likely want to source a DC-DC converter that is regulated at 12 volts to run the device simply to give te device a good filtered DC reference. it may not be necessary but just somethingto think about vs just connecting it to Ignition power..



TCM wise 98% of the TCM's on 2500 PTS built after 98 (3rd gen) will be throttle type J1939 which is what you want.. if you are buying a TCM from someone else like CA conversions or Jason at transmissiontuner, be sure to specify you want a J1939 throttle type TCM..

 

[Bouje bus]

The converter arrived quickly. Seems like a solidly built little box. 6 input wires, pwr/gnd, 2 j1708, 2 j1939. I have a voltage regulator on order (that KS for the suggestion Chris) for testing I have It plugged into the Fuse box for now.



I'm struggling with the output rs232. The output side if the box is female 9 pin. Attaching a pic for size reference. Posting now as I keep losing my text working off my phone.

 

[Bouje bus]

I got a j1939/j1708 to computer cable, but it was a 16 pin connector.

Then I tried db9 to rs232 cable, it was also a female connector. I got 2 different styles of male to male connectors to bridge the gap, but I question the wiring. One adaptor has the plugs 180 inverted, the other is longer, and plugs have the same orientation, but the pins are not straight through.

My questions today are how do I connect female db9 to computer and what is the best (inexpensive) program to read signals and set this as address for tcm to "read" it.

 

[cadillackid]

You need a USB to serial device for your computer. The right one will be a USB port to a 9 pin male. I’m not sure what cable you are using now to know if you have a rx/tx mismatch.

Software wise I was thinking the converter had a test program you could download that has a terminal program to talk to the rs232 side.

Tera term is a windows program I have used in the past to talk serial .

 

[nikitis]

Hardware wise I get it. Software wise no.

Just ensure the device has power, get a rs232 daughter board which connects to a USB cable, and ensure TX and rx are connected to your device and use serial connection in putty application on windows on the right com port. If the device outputs anything it'll light up your terminal. Not sure why we are trying to hook it up to a PC first are we reverse engineering the device? Does it not come with hookup instructions?

 

[Bouje bus]

Nikitis, i'm with you on this one. i'm a mechanical engineer that worked my way through school as a mechanic. i can figure out the mechanical side, and electrical hardware stuff, but this communications stuff is well outside my wheelhouse.
when i started this endeavor, i mistakenly assumed my 1998 truck and 3 pin connector would be a close to plug-n-play with the allison TCM.
lo and behold, it is a 1997 chassis, and i still don't know what the 3 pin plug with twisted wires goes to. probably a 1708 connector.

so, i found the 1708 to 1939 converter. installed a 120 ohm resistor parallel to the converter to get a 60 ohm "network" knowing nothing about RS232 data, I have bought several iterations of DB9 cables to try to connect to a PC, just to see the signals and if the converter is converting.
the output of the converter box is female. the first cable i bought (DB9 to Cat9 looking connector) was female DB9. not knowing any better, still thinking in terms of electricity, not comms, i picked up a male to male DB9. i plugged that into the scanguage display and may have let some smoke out of the plug. just because the cable says RS232 and the display says RS232, they don't play nice. i think i swapped the power out of the converter by using the male-to-male adaptor.

so, i picked up a DB9 to USb cable from best buy. the AUelectronics site has data monitoring and a cool dashboard you can download for free.
i've got the PC seeing the converter box, but not the J1939 data. at this point i've tried to download the teraterm program 2 times unsuccsessfully.
i've ordered cable #4 - DB9 to USB with internal chip. hopefully once i get to the point of being able to see the data i can start trying to get the TCM to see the converter box as the ECM.


baby steps.

for anyone that has made it this far, here are a couple links i found that explain CAN bus hardware/software and the specifics of the J1939 communication.
https://www.csselectronics.com/pages/can-bus-simple-intro-tutorial
https://www.csselectronics.com/pages/j1939-explained-simple-intro-tutorial

 

[cadillackid]

OK im confused a bit here..


the MALE connector on the AU device is what you wire up to the vehicle datalinks.. the Female is the RS232 side which goes to your PC..


the USB to RS232 cable that is on the AU site is what you use to plug directly into the RS232 female on the AU device,,



the scangauge should NEVER be connected to the RS232 side.. thatd essentially connecting a variant of RS485 to RS232.. something will likely be destroyed..


if your scangauge has a 9 pin cnnector directly on it.. it is NOT likely the same pinout as your AU device so dont plug the 2 together in any way.. for testing you CAN connect the J1708 or J1939 pins to the appropriate wires on your AU device.



I have no idea what model scangauge you have.. is it designed for J1708 or J1939, or both? it will have specific pins to commect to the datalink..



if you bought one of the premade 9 pin female to harness connectors then the yellow / green are your J1939 wires and the purple brown are your J1708..





the cable you are buying is not just a USB to 9 pin adapter.. it is a USB to serial converter... most of them have drivers built into windows and will show up as a COM port in device manager (windows)..



NEVER connect that USB to serial device in any way to the Male side of the AU device..


teraterm I went to teraterm site and clicked on the release page under "download".. clicked 5.2, and then scrolled down to the "assets" section and downloaded the program easily.. I downloaded the zip.


https://github.com/TeraTermProject/teraterm/releases/tag/v5.2


I ordered one of these as it looks like something I could use for my digital dash project..

 

[Bouje bus]

All lessons learned the hard way

OK im confused a bit here..

the MALE connector on the AU device is what you wire up to the vehicle datalinks.. the Female is the RS232 side which goes to your PC..

the USB to RS232 cable that is on the AU site is what you use to plug directly into the RS232 female on the AU device,, i didnt know better and didnt order that cable when i ordered the converter. it is on order now.


the scangauge should NEVER be connected to the RS232 side.. thatd essentially connecting a variant of RS485 to RS232.. something will likely be destroyed..Yes, it was. smelled weird and now one plug doesnt work.


if your scangauge has a 9 pin cnnector directly on it.. it is NOT likely the same pinout as your AU device so dont plug the 2 together in any way.. for testing you CAN connect the J1708 or J1939 pins to the appropriate wires on your AU device.


I have no idea what model scangauge you have.. is it designed for J1708 or J1939, or both? it will have specific pins to commect to the datalink.. the scanguage was in the bus when i bought it. the connector doesn't have wires for the 1939. it still reads the 1708 data.


if you bought one of the premade 9 pin female to harness connectors then the yellow / green are your J1939 wires and the purple brown are your J1708..


the cable you are buying is not just a USB to 9 pin adapter.. it is a USB to serial converter... most of them have drivers built into windows and will show up as a COM port in device manager (windows)..

NEVER connect that USB to serial device in any way to the Male side of the AU device..

teraterm I went to teraterm site and clicked on the release page under "download".. clicked 5.2, and then scrolled down to the "assets" section and downloaded the program easily.. I downloaded the zip.
i'll try this one. the zip in the AU site have not worked for me.



https://github.com/TeraTermProject/teraterm/releases/tag/v5.2


I ordered one of these as it looks like something I could use for my digital dash project..

i'm documenting my screw ups so that hopefully the next guy that doesn't know any better will save some time/energy and hardware.

 

[Bouje bus]

i'm really hoping that by the end of the week i can post up a:

buy this converter, this wire, and that adaptor, connect it this way, change this parameter and badabing, your older than dirt truck can talk to a newer transmission.

not there yet, learning a lot along the way. so far, i haven't managed to screw anything up permanently, other than one port on the scanguage doesnt work anymore. the 2nd port is still working.

i did pick up a DC-to-DC filter for the converter power. i plan on wiring that in while I wait for the proper cable to show up.

with the cable that has the serial to USB converter, will i still need to run the teraterminal to read the 1939 data? or will the AU data message center handle the incoming data?
https://auelectronics.com/System-MCSJ1939-001.htm

once i get to the point of seeing the 1939 data, what is required to tell the TCM to accept data from the converter box.

Chris, thank you for all your information.
Again this is totally new to me and hopefully others can learn from my mistakes.

 

[cadillackid]

hopefully your device didnt die.. yeah teraterm is an active open source project so the links change and im guessing AU prob didnt update it.. I didnt even see there was link to it on AU site.


I use RS232 pretty frequently in my job so ive got several software programs including teraterm on my machine already..



I ordered one of these, when i get it, I can help you guys set it up.. my T444E has J1708 on it so i should be ableto unplug my allison 1000 from the factory J1939 and plug it into this converter to see how it works..



hopefully I can help decipher some of the confusion here