A50/T14 confusion

[comnrailpwr]

Title should read A50/T14. Not T15

I have a customer with a failed TCM in his 09 LMM Duramax. He bought a replacement (used) and I swapped them. The replacement was service number 24256861 and the old one is 25978353. Not knowing this I just read the original which auto detected as an A50 and opened as an A50 file. Replaced. Auto detected the new one as an A50 and licensed ok. I I tried to load the original tune file in, the flash started briefly in the programming and got an error of which I thought was $0600. That's not a valid error so I'm thinking it was $06CC. After that error I began to re attempt with $0101. The TCM will no longer autodetect and continues to give $0101. I did unplug the TCM for a but and it did autodetect again as an A50. Same dance when I went to full flash tho, $0101. Anyone have any idea? Possible bad used TCM. Seller claims no issues. Possible this is a A50/T14 mismatch confusion and I inadvertently bricked the replacement TCM? What's the differences and are both files comparable with each other without bricking the TCM? Not sure where to go from here other than get a new one and try again. Just don't want to brick another if this is an issue on my end. I have flashed several A50 with stock and modified files without ever a hiccup. This is my first replacement job. I did change the vin in the controller prior to flashing and the vin in the tune was correct. Sorry for the rant, just trying to be detailed.

[GMPX]

Is a T14 supposed to be a direct drop in replacement for the A50? Can TIS flash A50 files in to the T14 ok?
FWIW we have not seen a T14 TCM here to know what differences there is to be causing issues.

[comnrailpwr]

I did verify the replacement TCM says on it it is a model t14. The original is model a50. T14 is an ACDelco part and the replacement from what I have gathered. I don't know what the differences are. EFILive does recognised the t14 as an A50 on auto detect but it will not take a flash. After the initial attempt where it attempted too. I think trying to flash an A50 file in this bricked it somehow. After it sits a while it will still auto detect tho is that means anything. Not sure what that process involves. The two units look identical.

[comnrailpwr]

He is going to take it to the dealer and try a flash with tis. I have a feeling it's not going to work tho.

[GMPX]

With GM controllers the Autodetect typically works based off a list of known part numbers we request, GM might have carried over a P/N that is shared between the two TCM's but they are in fact different.....that would be bad.
Do you know if the T14 been out long ?

[comnrailpwr]

I believe it to be out for at least a year and half.

[comnrailpwr]

TIS would not connect either. The controller is dead. So maybe this should be looked into. As stated the controller began to flash initially and error out. I can only assume the controller randomly died or it died because EFILive auto detected it as an A50 and I attempted to FF an A50 file. I sent all the trace files the day before I started this thread in a support ticket. If this isn't a coincidental controller failure then I feel something needs to be implemented to prevent this from happening in the software. Maybe the trace files will give some insight, maybe not. Not sure how those work. From now on I will be pulling all TCM on 09+ duramax trucks to check the model number. I would advise others do the same, we cannot currently rely on the auto detect feature. I'm all ears if any other tuners have any input.

[rcr1978]

https://forum.efilive.com/showthread.php?24979-2011-TCM-Full-flashing

Read this I bet someone sold you a pos. I have replaced numerous A50's with T14's with no issues all with EFILive software. Last one was a month ago so one release ago approximately on the software.

[comnrailpwr]

https://forum.efilive.com/showthread.php?24979-2011-TCM-Full-flashing

Read this I bet someone sold you a pos. I have replaced numerous A50's with T14's with no issues all with EFILive software. Last one was a month ago so one release ago approximately on the software.
I have read that. Different situation. You replaced a t14 with an A50 which I have never had any problems programming.. Have you or anyone ever successfully full flash an T14 with EFILive Software using a file you pulled from a failing A50?

[rcr1978]

Ok missed that no I have not tried to flash a A50 2009-2010 OS into a 2011+ T14.

[comnrailpwr]

The T14 is a replacement for the 2009-2010 as well is what I am being told. I unknowingly attempted to flash it as an A50 because that is what it auto detected as. I thought I was replacing like for like so to speak but that wasn't the case. It did begin the flash so that's what has me thinking it was an ok unit before I attempted to flash. I wish I tried to read out the replacement T14 prior to flashing to see if it would read. It licensed fine.

[rcr1978]

If it's a direct replacement then when flashed with TIS its going to get the 09-10 OS then and every dealer replacing them would be killing them. I do think this style of TCM (T14)) has been a pos from the beginning and hs been prone to fail even on flashes. All the ones I have done lately have been replacing T14's with a new T14. You would think it would be fine since the 2011 T14 OS worked in the 2010 A50.

[GMPX]

That is interesting

[rcr1978]

I have a spare T14 here that worked intermittently if I can get it to act normal for a bit I will try putting a 09-10 OS in it when I get time. I've already tuned it and it's already broke so it won't hurt my feelings if it takes a shit.

[GMC-2002-Dmax]

The replacement TCM T14A is a POS as well.

I have a bricked on here on my desk, TIS asks for the Hardware Number and even with the correct HW# and VIN entered in the TIS2WEB System it still bricked.

If you want the TCM to play with Ross I can ship it to you, its a paperweight, if you want a project I have one for you to play around with !!!

Lemme know.......

[comnrailpwr]

I think at the least we can prevent the software detect them as an A50. I'm interested to see what happens when you try to flash an 09-10 OS in one. If it works fine then I just had a bad egg I would say.

[GMPX]

I have a bricked on here on my desk, TIS asks for the Hardware Number and even with the correct HW# and VIN entered in the TIS2WEB System it still bricked.
OK, that is bad, I wonder how that has not fed back to GM / Allison from the dealers to get resolved.


If you want the TCM to play with Ross I can ship it to you, its a paperweight, if you want a project I have one for you to play around with !!!
I have lots of projects already thanks :grin:
Are you guys sure the T14 isn't supposed to be a replacement for the A40?


I think at the least we can prevent the software detect them as an A50. I'm interested to see what happens when you try to flash an 09-10 OS in one. If it works fine then I just had a bad egg I would say.
If anyone has a read from one of these T14's I can probably configure the software to not detect or attempt to flash one of these T14's if they just don't work.

[rcr1978]

Oh no don't do that the T14's are in all the 2011-2015 trucks, if thats done then we can no tuna anymore :master: :grin:

[Chuck CoW]

With GM controllers the Autodetect typically works based off a list of known part numbers we request, GM might have carried over a P/N that is shared between the two TCM's but they are in fact different.....that would be bad.
Do you know if the T14 been out long ? I tis flashed it twice and it died...again..... What now...????????? Chuck, CoW momentarialy STUCK like a pig.... stuck

[GMC-2002-Dmax]

The TCM will report a Valid SN#, when attempting to read it states "FLASH RECOVERY" then errors out $0101

But its alive enough to give up its TCM SN#

Executing: C:\Program Files (x86)\EFILive\V8\Config\A40_R.obj
Virtual Machine Started
Script Loaded
Script Verified
Flash recovery mode...
Please: Wait...
Script exited with code $0101: No data received


But its junk for sure.

T14A hdw # 24256864

Supposed to be a A40 replacement.......but they are JUNK !!!

[comnrailpwr]

That's exactly what the one I had fail was doing.

[Chuck CoW]

The TCM will report a Valid SN#, when attempting to read it states "FLASH RECOVERY" then errors out $0101

But its alive enough to give up its TCM SN#

Executing: C:\Program Files (x86)\EFILive\V8\Config\A40_R.obj
Virtual Machine Started
Script Loaded
Script Verified
Flash recovery mode...
Please: Wait...
Script exited with code $0101: No data received


But its junk for sure.

T14A hdw # 24256864

Supposed to be a A40 replacement.......but they are JUNK !!!

20879

This controller did not autodetect the TCM when it drove in. It's been doing much of what you said it would be doing. :(

This is a 2007 CLASSIC and TIS lists a bunch of controller options when I try to flash it. I lifted the controller to get the correct

part number and it failed anyways....

I'll keep you posted.

Chuck CoW

[Chuck CoW]

20879

This controller did not autodetect the TCM when it drove in. It's been doing much of what you said it would be doing. :(

This is a 2007 CLASSIC and TIS lists a bunch of controller options when I try to flash it. I lifted the controller to get the correct

part number and it failed anyways....

I'll keep you posted.

Chuck CoW

Strange..... The truck starts for one half second and dies with the non responsive TCM in the truck....

Got the TCM back online and updated and now the Truck runs fine.

Never saw that before.

Chuck CoW

[killerbee]

This subject has come up in various threads for years, and has created headache after headache. I have a working T14 I will be happy to ship to you Ross. They have been available for 5 years, and been nothing but confusing.

[GMPX]

Thanks Michael, if you can let me know the P/N we'll just order one.

[killerbee]

Thanks Michael, if you can let me know the P/N we'll just order one.

These are what I have on file

24256861
24257038
24256670

[comnrailpwr]

24256861 is the T14 I had that failed

[GMPX]

Wow, $400 a pop, that is crazy when you consider the price of some of the other controllers GM sell.

[GMC-2002-Dmax]

24256864 is the T14A I had that failed

[GMPX]

Oh no, T14 and T14A now, there's two of them?

[GMC-2002-Dmax]

Just say the word, it will be on its way to you............LOL

I hate to see paperweights and its too light for a door stop

HAHAHAHAHA

[GMPX]

Let me just check what I have lying around here, TCM's tend to get thrown as deep in a pile of mess as possible :music_whistling_1:
If I don't Tony maybe send it to Guy to make things easier, he often is our middle man for getting controllers out of the US.

EDIT: I found an A41 (whatever that is!) but no T14.

Thing is the way I am reading all this it appears that all we will end up doing is bricking them when trying to flash them like TIS does. Is there a fundamental flaw with this TCM?

[GMC-2002-Dmax]

Let me just check what I have lying around here, TCM's tend to get thrown as deep in a pile of mess as possible :music_whistling_1:
If I don't Tony maybe send it to Guy to make things easier, he often is our middle man for getting controllers out of the US.

EDIT: I found an A41 (whatever that is!) but no T14.

Thing is the way I am reading all this it appears that all we will end up doing is bricking them when trying to flash them like TIS does. Is there a fundamental flaw with this TCM?

Not sure, it will be on its way back to GUY, he had it for a while an had no luck, I am trying to find someone with ALLISON Tools to see if they can revive it.

And yes, I recommend getting a junkyard A40 to everyone with a tcm failure, these are junk controllers

[GMPX]

I am trying to find someone with ALLISON Tools to see if they can revive it.
If it is dead I don't want it thanks, probably not much I can do.

[vectorbundle]

Let me just check what I have lying around here, TCM's tend to get thrown as deep in a pile of mess as possible :music_whistling_1:
If I don't Tony maybe send it to Guy to make things easier, he often is our middle man for getting controllers out of the US.

EDIT: I found an A41 (whatever that is!) but no T14.

Thing is the way I am reading all this it appears that all we will end up doing is bricking them when trying to flash them like TIS does. Is there a fundamental flaw with this TCM?

A41 is not for GM pickups or MD trucks, forget it.

T14A (GM serv #24256864 on sticker, part #24256671 and T14A on the case) is Delco branded version of Allison A46 (part # 29546675 and ATA4601 on case). they are the same hardware.

T14 (GM serv #24256861 on sticker, part #24256670 and T14 on case) is Delco version of Allison A50 (serv #25978353, part #29545535).

T14 is to A50 what T14A is to A40 -- sort of. there are some differences that are part of the boot level. SPS does not write to that, it only writes the OS and trans cal segments.

when you flash an 06-08 GM pickup with SPS you must select the TCM type (list of part/service #s that just determine if it's T14A/A46 HW or A40). the cal segment for 08 will be the same 24257976. the OS will be different 29541751 (A40), 24256580 (A46). cross flashing will brick. you will find similar pattern when selecting A50 vs T14 for 09-10 pickup -- same trans cal, different OS.

you cannot SPS an A50 selection into a T14, it will brick. generally you cannot flash a file you read out of an A50 with EFIlive into a T14, it will brick. just as flashing A40 OS and cal into an A46 will brick. in some cases i can recover them.

for some strange reason for 2011+ GM pickups the same GM flash works in A50 and T14 (at least that used to be case, they may have made some "improvements"). i haven't figured out yet why that is, i don't have any A50s left to test stuff on and generally have no reason to use them.

there are a couple of problems specific to SPS and MD trucks. GM never updated their MD Allison A40 and A50 software for T14A and T14. there IS no MD calibration in SPS for the new controllers. and there is no TCM hardware selection screen. so people install a new T14A in their 08 MD trucks figuring GM says it's a replacement for an A40 and flash it for an 08 MD VIN... brick. SPS a T14 in 09 MD truck... brick.

what's worse, SPS also bricks an A50 when flashing for an 09 MD truck (that's an error with SPS, it's not a problem with the controller). A40s flash OK for 06-08 MD VINs. but as far as EFIlive is concerned, as long as one flashes only what was read out of a TCM with the same HW, there is no problem. there is no fundamental flaw in the T14 or T14A TCMs. the fundamental flaw is GM's support and documentation.

[GMPX]

Thanks, what an amazing write up and what a mess GM created!
I might copy / paste what you wrote as a sticky thread.

[Chuck CoW]

Thanks, what an amazing write up and what a mess GM created!
I might copy / paste what you wrote as a sticky thread.

I appreciate it as well..... I already copied the text to my little "cheat sheet", my grand GM controller cross reference. :grin:

Great info! The night I posted in this thread I thought I was going to die..... I think it was Ross that bailed me out of my disaster at like 4:30am.:rockon:

Thank god for Ross!
Chuck CoW

[GMPX]

Great info! The night I posted in this thread I thought I was going to die..... I think it was Ross that bailed me out of my disaster at like 4:30am.:rockon:
Oh yeah I remember that...what can I say, I felt sorry for you with your head about to explode at 4:30am your time trying to fix that SPS mess. You know how it works Chuck, just don't mention T43 and you'll get a response from me :hihi:

[Chuck CoW]

While I don't want to give it up, TIS is a fucking mess.... Tried to flash a 2009 suburban HVAC the other day and it wiped out and I got *-=%7 for a part # the second time I tried to flash it....

screen went totally blank and no responsive.....

TECH 2 - remote / passthru / MDI / MONGOOSE / openport / J Box etc.... NOTHING would talk to it.

Tried to do a TECH II flash but the tool would not work on a 2009 vehicle. 2007 was the latest....

SO, after 4 hours of VERY filthy language..... I told the tech 2 is was a 2007 - requested info... and TIS loaded a cal into

the TECH 2 (remote) and went back to the car and it worked..... Fuck YEAH! After 4 hours with freshly updated MDI and TIS

and that shit system falls on it's face.... had to power down the unit (the whole truck) for each retry and HOW STUPID. it reminds

me of the night I spent doing a "quickie" Duramax tune and the TCM failed on a routine TIS update.....

What a mess it is..... :(

Chuck CoW

[vectorbundle]

Thanks, what an amazing write up and what a mess GM created!
I might copy / paste what you wrote as a sticky thread.

no problem. the whole thing is totally moronic. GM could (and should) just release MD cals for the new controllers with a TCM selection screen. then all that remains will be the occasional SPS "anomalies"...

btw, it would be nice to have an A50 stream available (it is now a "legacy" controller after all). any plans for this?

[DURAtotheMAX]

A41 is not for GM pickups or MD trucks, forget it.

T14A (GM serv #24256864 on sticker, part #24256671 and T14A on the case) is Delco branded version of Allison A46 (part # 29546675 and ATA4601 on case). they are the same hardware.

T14 (GM serv #24256861 on sticker, part #24256670 and T14 on case) is Delco version of Allison A50 (serv #25978353, part #29545535).

T14 is to A50 what T14A is to A40 -- sort of. there are some differences that are part of the boot level. SPS does not write to that, it only writes the OS and trans cal segments.

when you flash an 06-08 GM pickup with SPS you must select the TCM type (list of part/service #s that just determine if it's T14A/A46 HW or A40). the cal segment for 08 will be the same 24257976. the OS will be different 29541751 (A40), 24256580 (A46). cross flashing will brick. you will find similar pattern when selecting A50 vs T14 for 09-10 pickup -- same trans cal, different OS.

you cannot SPS an A50 selection into a T14, it will brick. generally you cannot flash a file you read out of an A50 with EFIlive into a T14, it will brick. just as flashing A40 OS and cal into an A46 will brick. in some cases i can recover them.

for some strange reason for 2011+ GM pickups the same GM flash works in A50 and T14 (at least that used to be case, they may have made some "improvements"). i haven't figured out yet why that is, i don't have any A50s left to test stuff on and generally have no reason to use them.

there are a couple of problems specific to SPS and MD trucks. GM never updated their MD Allison A40 and A50 software for T14A and T14. there IS no MD calibration in SPS for the new controllers. and there is no TCM hardware selection screen. so people install a new T14A in their 08 MD trucks figuring GM says it's a replacement for an A40 and flash it for an 08 MD VIN... brick. SPS a T14 in 09 MD truck... brick.

what's worse, SPS also bricks an A50 when flashing for an 09 MD truck (that's an error with SPS, it's not a problem with the controller). A40s flash OK for 06-08 MD VINs. but as far as EFIlive is concerned, as long as one flashes only what was read out of a TCM with the same HW, there is no problem. there is no fundamental flaw in the T14 or T14A TCMs. the fundamental flaw is GM's support and documentation.

Awesome tech info, thanks!!

So people with 06-09 MD trucks are just SOL if they need a new TCM? Their only option is to find a used A40 for 06-08?? And nothing for 09? Or just put a used A40 into an 09 MD if you need replacement?

And you said A50 will brick when flashing for an 09 MD? Did the 09 MD's come with an A40 or A50 from the factory? So if they came with A50's from the factory, you're saying there is "NO" reflash at all for any 09 MD's?

Does the A50/T14 not have J1850/Class2 comms capability?

On another note....do you have any ideas why its "somewhat common" for 2011's to eat TCM's?

Ben

[DURAtotheMAX]

When they brick, do they fully go brain dead and not even boot? Or just wont be recognized by SPS/dealer-level software?

Can they be recovered by Allison software, or "other" GM software?

[vectorbundle]

A50 has no J1850 capabilities afaik. a takeout A40 (with appropriate programming) will work, people used to swap them over to tune before A50 support was available. for a *new* TCM, afaik MD guys are SOL with SPS. they are probably SOL with a typical Allison dealer too because their system has no GM cals anymore.

i have ways to set up the new controllers for MD guys, the point is it can't be done with SPS. these TCMs can be "converted" but that's not exactly an off-the-shelf OEM process for a typical guy out there with a bad TCM.

what i described is not necessarily an exhaustive or up to date state of affairs with SPS. i don't use it anymore. there were also cases when SPS bricked TCMs for no discernible reason whatsoever even with correct TCM HW selected. if you are not careful and flash the wrong TCM -- definitely brick, so at least don't do that. correct TCM -- eh, maybe still brick. the system sucks (not the TCM). recovery is impossible more often than not.

i agree that 2011 TCMs *seem* to fail disproportionately. i don't know why.

[DURAtotheMAX]

A50 has no J1850 capabilities afaik..

Ah yeah, makes sense...since the GMT-560's still use Class 2 for the instrument cluster and body stuff.

[comnrailpwr]

This has struck me again. Customer brought me a 2009 with an acting up A50 TCM. the replacement that dealer gave him was T14. I read out his Factory A50 TCM as he had transmission tuning. Are then installed the T14 and read that tune out as well. It had some data in it but looked a lot different compared to the regular truck data. I then flashed his original A50 file into the T14 replacement. That's generally what I always do. If flashed in without any issues but it had a traction control light on and was shifting hard into gear. I then made all the changes to the T14 file I read out of the new TCM to match what his A50 TCM originally had. That file will not Flash and errors out $0101. Both tcm's do auto-detect as A50. I'm not sure what to do with this problem without tis. I now do have a tech2 but have yet to use it.

[GMPX]

Does the T14 read as an A50? Are you able to post up the T14 file that was read out if that is the case.

The user 'vectorbundle' said above....
"You cannot SPS an A50 selection into a T14, it will brick. generally you cannot flash a file you read out of an A50 with EFIlive into a T14, it will brick."

Given that, I don't know what you are supposed to do with your T14's.

[comnrailpwr]

Yes it auto detected, read out and saved as an A50. I see his remarks now after I came back to this thread. For some reason I un followed it and stopped getting notifications unfortunately. Having trouble attaching file via my phone and external drive. I'll email it to you.

[Chuck CoW]

Does the T14 read as an A50? Are you able to post up the T14 file that was read out if that is the case.

The user 'vectorbundle' said above....
"You cannot SPS an A50 selection into a T14, it will brick. generally you cannot flash a file you read out of an A50 with EFIlive into a T14, it will brick."

Given that, I don't know what you are supposed to do with your T14's.

I'm generally VERY careful with later TCMs..... When TIS flashing TCMs, (especially in Duramax trucks) many times the

software asks for a TCM PART NUMBER.... and the list usually has 20+ choices.... Don't want to own that one!

Have the replacement flashed by someone with TIS and then start with the latest calibration that was read from the

controller to avoid problems.

Chuck CoW