T87 Swaps

[kidturbo]

Had an Allison transmission guru hit me up last week about making a T87 communicate with E38 and E67 ECMs. Seems people are into sticking the 8spd behind cranked up LS gassers. And while the T87 is used to control other transmissions beside the Allison, it's only compatible with 2016 and up GMLAN GlobalA ECMs.

So I took a peak and found a few canbus data differences between the older E38 and newer E92 ecm. But see nothing I can't resolve by adding a little data translator to the mix.

So while setting here wiring this TCM up to an E38 on the beach, question is, should build one for LBZ/LMM/LML also??

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[Cougar281]

I personally wouldn't be opposed to be able to replace my A40 with a T87/T87A.... supposedly ATS has something for the LMLs, but it doesn't seem to be LMMs or lbzs... and they're REALLY proud of it... if you figure something out and need a guinea pig...

I should go troll my local U-Pulls for a TCM or three and a connector, but I suspect the T87 is a bit new for my local yards.

 

[kidturbo]

Ok I'll hit ya up once I have something ready to go.

Biggest thing is that T14 male side connector is a one off deal. But I have someone who claims to have solved that issue. And from what I learned, running a T42 to collect shafts speed data in the boat, if this device works on E38 swap, it should also work on LBZ/LMM.

So one would just need a $100 connector adapter, then swapping to T87/A would be plugNplay without breaking the



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[Cougar281]

Ok I'll hit ya up once I have something ready to go.

Biggest thing is that T14 male side connector is a one off deal. But I have someone who claims to have solved that issue. And from what I learned, running a T42 to collect shafts speed data in the boat, if this device works on E38 swap, it should also work on LBZ/LMM.

So one would just need a $100 connector adapter, then swapping to T87/A would be plugNplay without breaking the



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That would be.... AWESOME in my opinion. ATS markets their solution with their 'copilot', which not everyone wants or needs, and like I said, they're REALLY proud of it.. a solution to run a 06-10 or so Allison on an obtainable T87/T87A for a couple hundred bucks vs an unobtanium A40/A50/T14 or ATS"s several grand for their unit that includes their co pilot that most don't want or need...... Of course there is the 'planned obsolescence ' that part of which we're t trying to overcome....

And yeah, the male side A40/A50/T14 is a bit of a challenge...

 

[kidturbo]

Would ya believe me if I said I have it solved already?

Thanks to a little support from a couple people with way more talent than spare time, I caught a bone.. Guess sometimes it pays to be that guy not looking to one up everyone out there. Cause the bone was juicy, and I've been chewing on it for three days straight now..

Couple ways this mix and match issue can be tackled. With proper data in hand, one could realistically write a couple cax files for the ECM and TCM that adjust a few canbus messages, swap out the TCM connector, and be rolling before lunch tomorrow as if Detroit shipped it that way. But that takes the plug-N-play aspect out of the picture. And if someone ever replaces one piece of that pair, your gonna be limping around until the correct files are reloaded. So we will leave that for another day, under they yes it can be done file..

This little T87A is a pretty sweet piece, with a load of potential power. Much of which looks to be unharnessed in normal operation. But it also listens to a lot of unrelated stuff on the CANbus. Like ID 0x1FC - Long_Lat_Sensor_Data_HS. Why would a TCM care where it is on earth? Maybe it's IDR related, because even collision and rollover data is found in our listening ID list. Guessing if ya pull the freezeframe from one of these pieces that's been in a crash, ya can probably learn a lot about that vehicles last ride. Not just the SRS module logging every parameter of that last 30 seconds before impact any more. The once little known of, and never spoken about outside a courtroom, GM onboard Black Box data recorder, sure looks to have become the Black Boxe"s" around model year 16.. Just a friendly FYI...

To actually utilize this piece in a way that doesn't require advanced skills in tuning and wiring, we need to stick with the basics. And lucky for us, this TCM doesn't seem to requires all that extra data to function correctly. Just some specific engine parameters, and a few inputs from our BCM if we wish to retain manual mode, tow haul, and tap shift functions. But it shouldn't be a problem to take what data our LBZ/LMM ECM currently speaks, run it through an extra node to give it a voice over, and our T87 is none the wiser. Same thing with a couple messages heading back to our ECM. All the years of recorded data manipulating GMLAN, finally good for something.. So I have a simple prototype heading out later this week for some real world testing in the E38 based config.

What I could use right now is a couple A40/A50 T14 style TCM's that are beyond repair. I've sourced the T87 side connectors, but probably going to 3d print my own mating sockets for our factory harness side. Unless someone has a part # I've missed, or can rob a truck heading to,,,, well I'm exploring all options. LOL. In exchange for a fried T14, I'll gladly let ya beta test this new adapter soon as I can wire one up. Making all this work on the bench is great, but no substitute for real world data. If ya can score an unlocked 87A, I'll provide the rest..

 

[pl_silverado]

I have a good A50 with a broken housing you could pilfer for parts, willing to do the beta testing on one of my spare trucks.

 

[juddski88]

Would ya believe me if I said I have it solved already?

Thanks to a little support from a couple people with way more talent than spare time, I caught a bone.. Guess sometimes it pays to be that guy not looking to one up everyone out there. Cause the bone was juicy, and I've been chewing on it for three days straight now..

Couple ways this mix and match issue can be tackled. With proper data in hand, one could realistically write a couple cax files for the ECM and TCM that adjust a few canbus messages, swap out the TCM connector, and be rolling before lunch tomorrow as if Detroit shipped it that way. But that takes the plug-N-play aspect out of the picture. And if someone ever replaces one piece of that pair, your gonna be limping around until the correct files are reloaded. So we will leave that for another day, under they yes it can be done file..

This little T87A is a pretty sweet piece, with a load of potential power. Much of which looks to be unharnessed in normal operation. But it also listens to a lot of unrelated stuff on the CANbus. Like ID 0x1FC - Long_Lat_Sensor_Data_HS. Why would a TCM care where it is on earth? Maybe it's IDR related, because even collision and rollover data is found in our listening ID list. Guessing if ya pull the freezeframe from one of these pieces that's been in a crash, ya can probably learn a lot about that vehicles last ride. Not just the SRS module logging every parameter of that last 30 seconds before impact any more. The once little known of, and never spoken about outside a courtroom, GM onboard Black Box data recorder, sure looks to have become the Black Boxe"s" around model year 16.. Just a friendly FYI...

To actually utilize this piece in a way that doesn't require advanced skills in tuning and wiring, we need to stick with the basics. And lucky for us, this TCM doesn't seem to requires all that extra data to function correctly. Just some specific engine parameters, and a few inputs from our BCM if we wish to retain manual mode, tow haul, and tap shift functions. But it shouldn't be a problem to take what data our LBZ/LMM ECM currently speaks, run it through an extra node to give it a voice over, and our T87 is none the wiser. Same thing with a couple messages heading back to our ECM. All the years of recorded data manipulating GMLAN, finally good for something.. So I have a simple prototype heading out later this week for some real world testing in the E38 based config.

What I could use right now is a couple A40/A50 T14 style TCM's that are beyond repair. I've sourced the T87 side connectors, but probably going to 3d print my own mating sockets for our factory harness side. Unless someone has a part # I've missed, or can rob a truck heading to,,,, well I'm exploring all options. LOL. In exchange for a fried T14, I'll gladly let ya beta test this new adapter soon as I can wire one up. Making all this work on the bench is great, but no substitute for real world data. If ya can score an unlocked 87A, I'll provide the rest..

I find this all kind of amusing, because last year I had a harness builder up in NY who does standalone harnesses for Motec-controlled Vipers willing to work on this exact type of solution, and he decided to ask Kory if this was a viable solution, to which Kory replied that he had already spent a long time looking into it and couldn't make it work. A couple months later, ATS announced their conversion kit for the A50, and then I found a couple other conversion specialists had been working on the T87/A50 conversion too, so I decided to just stop spending time on it. Obviously I should nor have dropped it, and should have called you instead.

Pm me the shipping address to send you some stuff.

 

[Cougar281]

One thing I had thought of - how would Class2 be handled for the LBZs? Does the T87/T87A have the ability to communicate on Class2?

Are you using the T87, T87A, or both? The T87 would be better, I would think, since the T87 and T87A are nearly identical, except the T87A cannot be written to unless it's been unlocked, and as far as I know, only HPTuners can do that.

I've been keeping my eyes peeled for a T87 for cheap...

 

[kidturbo]

I find this all kind of amusing, because last year I had a harness builder up in NY who does standalone harnesses for Motec-controlled Vipers willing to work on this exact type of solution, and he decided to ask Kory if this was a viable solution, to which Kory replied that he had already spent a long time looking into it and couldn't make it work. A couple months later, ATS announced their conversion kit for the A50, and then I found a couple other conversion specialists had been working on the T87/A50 conversion too, so I decided to just stop spending time on it. Obviously I should nor have dropped it, and should have called you instead.

Pm me the shipping address to send you some stuff.

Sometimes ya just need to lay around the pack quietly waiting for the big dogs to get full up...

There was a lot better choice cuts than I require to make an 08 module speak to a 16+. So I can see why others might pass it over. For sure no cut/paste project either way. Just so happens I spend my days looking at Tank's view of the Matrix, rather than being Morpheus..

PM on the way.

 

[kidturbo]

One thing I had thought of - how would Class2 be handled for the LBZs? Does the T87/T87A have the ability to communicate on Class2?

Are you using the T87, T87A, or both? The T87 would be better, I would think, since the T87 and T87A are nearly identical, except the T87A cannot be written to unless it's been unlocked, and as far as I know, only HPTuners can do that.

I've been keeping my eyes peeled for a T87 for cheap...

From my experience, everything we need should be on the HSLAN with the LBZ. Class2 was on it's way out, and GlobalA was already the standard for every other platform by 06. Don't recall Class2 being pinned to the TCM. But maybe I missed it.

There is a few message differences between the LBZ and LMM. Specifically oil pressure I searched high and low for, but seems to be broadcast on class2 only rather than HSLAN that year. But I think the TCM was only HS data just like LB7 and LLY before it.

Seems everyone on the transmission tuning side of life is focused on these 87A models. Better processor I guess.. Also some changes to PWM solenoids on the 9/10spds that requires that specific unit. But I feel unlocking will soon become the old seed keys of days past. Soon as the big dogs make back their hardware investments and get tierd of doing tech support.. So I don't see that lock being a big hindrance going forward. And agree the 87 model is probably a good starter unit. Is what I have on the bench poking and prodding right now.

Should know in a few more days if there is any reason those can't be directly interchanged for A40/A50. Right now my biggest concern is the way GM played with tap shift and BCM related messages between the years. Believe parts of that has been explored some years back. So step one remains, make em all run, drive, sit and speak. Then sort out the smaller details before finalizing a design. At worst, a simple dip switch to identify the mating ECM.

 

[Cougar281]

From my experience, everything we need should be on the HSLAN with the LBZ. Class2 was on it's way out, and GlobalA was already the standard for every other platform by 06. Don't recall Class2 being pinned to the TCM. But maybe I missed it.

There is a few message differences between the LBZ and LMM. Specifically oil pressure I searched high and low for, but seems to be broadcast on class2 only rather than HSLAN that year. But I think the TCM was only HS data just like LB7 and LLY before it.

Seems everyone on the transmission tuning side of life is focused on these 87A models. Better processor I guess.. Also some changes to PWM solenoids on the 9/10spds that requires that specific unit. But I feel unlocking will soon become the old seed keys of days past. Soon as the big dogs make back their hardware investments and get tierd of doing tech support.. So I don't see that lock being a big hindrance going forward. And agree the 87 model is probably a good starter unit. Is what I have on the bench poking and prodding right now.

Should know in a few more days if there is any reason those can be directly interchanged for A40/A50. Right now my biggest concern is the way GM played with tap shift and BCM related messages between the years. Believe parts of that has been explored some years back. So step one remains, make em all run, drive, sit and speak. Then sort out the smaller details before finalizing a design. At worst, a simple dip switch to identify the mating ECM.

Yes, the LBZ uses HS GMLAN between the ECM and TCM, however, it uses Class2 to communicate with other modules such as the BCM and Instrument Cluster, possibly others as well like the EBCM.

 

[juddski88]

From my experience, everything we need should be on the HSLAN with the LBZ. Class2 was on it's way out, and GlobalA was already the standard for every other platform by 06. Don't recall Class2 being pinned to the TCM. But maybe I missed it.

There is a few message differences between the LBZ and LMM. Specifically oil pressure I searched high and low for, but seems to be broadcast on class2 only rather than HSLAN that year. But I think the TCM was only HS data just like LB7 and LLY before it.

Seems everyone on the transmission tuning side of life is focused on these 87A models. Better processor I guess.. Also some changes to PWM solenoids on the 9/10spds that requires that specific unit. But I feel unlocking will soon become the old seed keys of days past. Soon as the big dogs make back their hardware investments and get tierd of doing tech support.. So I don't see that lock being a big hindrance going forward. And agree the 87 model is probably a good starter unit. Is what I have on the bench poking and prodding right now.

Should know in a few more days if there is any reason those can't be directly interchanged for A40/A50. Right now my biggest concern is the way GM played with tap shift and BCM related messages between the years. Believe parts of that has been explored some years back. So step one remains, make em all run, drive, sit and speak. Then sort out the smaller details before finalizing a design. At worst, a simple dip switch to identify the mating ECM.

My initial concern/speedbump was the different speed sensor types and the way that engine speed and trans speed is handled between the different generations

 

[kidturbo]

I'll dig out a LBZ truck high speed CANbus capture to compare, and see if any TCM traffic was different between 06-08 years. Always favored the LMM hardware for stand alone builds because everything ya need for a proper dash, is streaming by default on the high speed side. While for the LBZ, I have to setup a dynamic pid structure to fetch oil pressure and few others missing parameters from that year. Which works ok in stand alone setups, but will typically cause conflicts if you add another scan tool or dashtop display to the mix. So we need to verify every required parameter across all years and models.

One good thing I've learned so far, GM stuck to the same set of ID's and byte structure from about 04 forward. They added to, and deleted a few, but what was engine RPM in a 2004 E38, is still RPM in 19 E41.. So once ya sort it all out on paper, ya can map the missing pieces and spoof that data to see how things work.

But yes, things like output shaft speed, are actually used by the ECM rather than a MPH number supplied by the TCM or ECM. I learned that in the T42 to LMM rig in my boat setup. While I set what I thought was a reasonable MPH fuel cut limit in both units, it was the output shaft tooth per revolution that snagged me up at 60mph true speed while trying to compare input/output shaft speeds. Was a head scratchier for a few.. Even though I knew what was going on, it didn't match our long perceived way the EFI instructions listed it. Same is true with the VSS wires on LMM. The pinout says connect here, while the actual OS never looks at that pin for a signal unless you flip a bit in a cax file. IE the never produced Standard Transmission option for LMM...

 

[Cougar281]

It'll be interesting to see where this goes. It seems like the T87, with an appropriate 'adapter harness', could be plug n play in the 07+ LMMs, since the electrical architecture hasn't changed much, if at all since then... The LBZs might end up the problem though, since they do use Class2 for some things.

I did manage to acquire a T87 that was out of a 16 Duramax truck, now to see if I can devise an adapter harness like I did long ago to connect an A40 to my truck when it was still a LLY/5Speed.

 

[LBZ]

Weren’t the T87/T87A much more flakey when it comes to flashing? In my world those are the only TCM’s I’ve ever had brick and hear about more of them than any of the older models. Just curious as to the point of this experiment (albeit very cool)?
Are the A40/A50 getting hard to find or something?

 

[Cougar281]

I believe the A40/A50/T14's are becoming unobtanium, which was one of ATS's 'Justifications' for their 3k price tag... I recall reading something along the lines of 'buy our kit now for $3k and have your truck on the road now, or have your truck down with a failed TCM waiting for one to become available someday maybe'. They may become more available again, but planned obsolescence and all that. They don't want us fixing our old trucks, they want us buying new ones.

 

[juddski88]

Weren’t the T87/T87A much more flakey when it comes to flashing? In my world those are the only TCM’s I’ve ever had brick and hear about more of them than any of the older models. Just curious as to the point of this experiment (albeit very cool)?
Are the A40/A50 getting hard to find or something?

It is more than an experiment. It is 100% required in order to maintain the viability of pre 2015.5 Allison-equipped trucks. The ability to convert will likely also carry over to other transmissions that are t87 and t87a controlled.

 

[LBZ]

Weird. I can get my hands on half a dozen used A40/A50 tomorrow where I live. Lots of parts trucks around. But I suppose someday you’re right they will become hard to find. Probably not a bad idea to get out in front of the forthcoming issue.

 

[juddski88]

Weird. I can get my hands on half a dozen used A40/A50 tomorrow where I live. Lots of parts trucks around. But I suppose someday you’re right they will become hard to find. Probably not a bad idea to get out in front of the forthcoming issue.

If you can get them for a fair price, let's make a deal...

 

[kidturbo]

Weird. I can get my hands on half a dozen used A40/A50 tomorrow where I live. Lots of parts trucks around. But I suppose someday you’re right they will become hard to find. Probably not a bad idea to get out in front of the forthcoming issue.

Few years back, I couldn't give the 3 spare A40/A50 units I had laying around away. Then about two years back, they became hard to find during the great chips shortage. But seems that wasn't the true root of the problem. All those units are ticking time bomb, and seem times getting short.. Check out some videos from the guys who repair em, and you will soon understand, they are doomed to die if you actually use your truck.. Then out of the blue it seemed, all of my LMM-LML Duramax buddies were searching for TCM's in the same year.. While some new GM stock is trickling in, FB market and eBay show the demand for working units is pretty high..

As for the T87 family, I personally know very little about the hardware. Only it's built by Hitachi, and can cover a wide range of of transmissions, besides the Allison. Nothing special jumped out at me in the EFI tune files, but transmission builders I know all say they can make em shift faster than any other TCM out there. So take it for what it's worth I guess. Main attraction to me is, not a piece of crap, and ready supply.