2009 LMM/A50 C5500 Kodiak

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June 22nd, 2016
silverfox

2009 LMM/A50 C5500 Kodiak

Greetings all. I'm an independent general auto service facility owner. Do a ton of stock Ford and GM repairs and a small amount of tuning. I have had EFI live since my old 1999 Tahoe with the 5.7 Vortec....My story is long, so grab a beer and popcorn. I'm looking for some feedback and opinion on something that I've been fighting. Here goes:

2009 Chevy C5500 tow truck with LMM D-max and Allison trans comes in. Trans in limp, trans light on, fault code in PCM for no communication with TCM. GM Tech 2 will not communicate with the TCM.

Less than 5 ohm resistance between two grounds at TCM and battery/chassis ground. Got both 12v constant and the one switched 12v.

Checked resistance at pin 6 and 14 at the DLC and have 60 ohms between the two and neither shorted to ground or power, and both solid continuity to the TCM, at less than 5 ohms.

Checked pin 2 at the DLC to the TCM and got less than 5 ohms, and it's not shorted to ground or power.

I checked resistance at the TCM connector of the solenoids in the trans. 5 ohm TCC, 24 ohm main mod, 5 ohm PC1, 24 ohm ss3, 24 ohm ss2, 23 ohm ss1, and 5 ohm PC2.

Everything says bad TCM.....So I put in a TCM....checked it for comms with the tech2 before flashing and bam, I have comms...code for not programmed, of course, but I have communication with it and none with the old controller.

So I go to Acdelcotds, flash the TCM with the MDI2 and GM TIS2Web and bam, no comms after flashing.

So...I assume I have an intermittent loss of power, ground, or CAN interruption during the flash or a short in trans that killed the new TCM....So I RETEST all powers, grounds, switched powers, and retest all my TCM output control circuits for shorts and all solenoids check as listed...I retest all comms wiring circuits and I have solid low resistance continuity between all the modules and each other and to the DLC and I check for any comms wiring short to ground or short to power and EVERYTHING looks good and I have my 60 ohms at the DLC between 6 and 14 and no shorts to power or ground.

Like the first time, everything says "bad TCM"......but I have N-E-V-E-R gotten a bad module out the box. NEVER.....so I test everything several more times....all continuity is good, no shorted solenoids, no shorts to ground, no shorts to power...so, another new TCM.....plug it in, and I have communication with the TCM with the Tech 2, I have a fault code for unprogrammed TCM, naturally. I flash it and BAM.....no communication.

Now I'm pissed....I break out my EFI Live and try to retrieve the calibration from the TCM and 4 out of 5 attempts I get a "no data received" and when it does, I get this calibration may be invalid....I read it, and the VIN is blank....so at this point I know in my mind SOMETHING on this truck is interrupting the flash and killing this TCM......so....I break out the benchtop programming setup and eliminated EVERY POSSIBILITY that it is something on the truck killing the TCM, I get a THIRD TCM and plug it into my benchtop setup along with the PCM....I have communication with the PCM and the TCM with my Tech 2 with the standalone harness, naturally I have a TCM code for "not programmed"......all good....I have communication....I know THAT wiring is sound, I know there are no shorts in any data lines, output devices etc because I am using a standalone benchtop programming setup...so....back to acdelcotds and flash the TCM with the benchtop harness using the MDI2....and once again, no programming errors, it completes just fine....and after the flash NO COMMUNICATION with the TCM.

Something in that calibration is bricking my new TCM's.....

So, fast forward to today....56 minutes on the phone with acdelcotds....they could see on their end where I had done the three successful flashes...they verified that calibration is the same as what it left the factory with. They had me do a vci flash on the PCM, they ran through the calibration line by line....they said, "at the end of the day, on our end, the programming is the responsibility of Allison"...he put me on hold to have another set of eyes look at everything, and he came back and said, "unfortunately their conclusion was that it must be something in the vehicle wiring, and I know that's not the case because you are using a stand-alone harness, but at the end of the day it may be something Allison has to get straight"....and just then I heard him talking to someone in the background...I hear him say, "so you heard from the guys at Allison then".....he comes back to me and says, "Allison claims that those modules on the medium duties are no longer supported by Tis2web and don't require programming....you'd think they'd put a note in the box or something...they claim you set it up with the Tech 2"

That sounded like rubbish to me. My question was then, "if that's the case, will setting it up with the scan tool eliminate the "module not programmed" fault code?" He has no clue....he assumes so....he's not Allison.

So....it all sounds implausible to ME, but at this point in time, programming it with TIS was in fact rendering the TCM useless.....my question then was, why does TIS it even allow programming? When the VIN comes up as a medium duty, why isn't that a message that pops up? Again, no clue he says....

So....there you have it....the word I get is the flash was bricking the module because it's not supposed to be flashed.....that's the story from Ac Delco....sounds implausible that this A50 can be just set up with the scan tool....so I do a little favor asking of a guy I know who worked for Allison division back a few years ago....he's going to have to do more digging, as he hasn't had dealings with any "older stuff" in a while, but he thinks the controller will INDEED have to be flashed, but that it is a calibration that is totally different from ANY calibration or OS GM uses on 2500 and 3500's and may indeed have to be done with Allison hardware/software only.

Anyone got any insight on the medium duty stuff? If I was able to get someone to read another A50 in another medium duty with EFI Live, would I be able to change the VIN and flash this medium duty A50 with it?

Just trying to get a customer back on the road. At this point, it's not about making a nickel, it's about customer satisfaction.
June 22nd, 2016
Taz

I don't work with diesels, so I have no idea about the Allison specifically.

I can tell you that I have destroyed more controllers by flashing them with SPS / TIS, than I have by flashing them with tuning software.

As an example, the PCMs that came in 1999 to 2007 (classic) light duty trucks, have a similar architecture, and should have a loosely similar flash protocol. I will not flash a 1999, 2000, or 2003 operating system into one of these using SPS / TIS - as this is prone to failure, and the destruction of the PCM in the process.
June 22nd, 2016
djv86

I know some of the older lb7 modules are perfered to be programmed via pass thru using tech2 pass thru not a mdi. Gm hotline told us( gm dealer ) that the mdi communicates at much higher rate of speed then some of the older modules and sometimes the module will not read the full program as it couldn't read as fast at the data was being programmed in
June 22nd, 2016
Road

Quote:

Originally Posted by silverfox

Greetings all. I'm an independent general auto service facility owner. Do a ton of stock Ford and GM repairs and a small amount of tuning. I have had EFI live since my old 1999 Tahoe with the 5.7 Vortec....My story is long, so grab a beer and popcorn. I'm looking for some feedback and opinion on something that I've been fighting. Here goes:

2009 Chevy C5500 tow truck with LMM D-max and Allison trans comes in. Trans in limp, trans light on, fault code in PCM for no communication with TCM. GM Tech 2 will not communicate with the TCM.

Less than 5 ohm resistance between two grounds at TCM and battery/chassis ground. Got both 12v constant and the one switched 12v.

Checked resistance at pin 6 and 14 at the DLC and have 60 ohms between the two and neither shorted to ground or power, and both solid continuity to the TCM, at less than 5 ohms.

Checked pin 2 at the DLC to the TCM and got less than 5 ohms, and it's not shorted to ground or power.

I checked resistance at the TCM connector of the solenoids in the trans. 5 ohm TCC, 24 ohm main mod, 5 ohm PC1, 24 ohm ss3, 24 ohm ss2, 23 ohm ss1, and 5 ohm PC2.

Everything says bad TCM.....So I put in a TCM....checked it for comms with the tech2 before flashing and bam, I have comms...code for not programmed, of course, but I have communication with it and none with the old controller.

So I go to Acdelcotds, flash the TCM with the MDI2 and GM TIS2Web and bam, no comms after flashing.

So...I assume I have an intermittent loss of power, ground, or CAN interruption during the flash or a short in trans that killed the new TCM....So I RETEST all powers, grounds, switched powers, and retest all my TCM output control circuits for shorts and all solenoids check as listed...I retest all comms wiring circuits and I have solid low resistance continuity between all the modules and each other and to the DLC and I check for any comms wiring short to ground or short to power and EVERYTHING looks good and I have my 60 ohms at the DLC between 6 and 14 and no shorts to power or ground.

Like the first time, everything says "bad TCM"......but I have N-E-V-E-R gotten a bad module out the box. NEVER.....so I test everything several more times....all continuity is good, no shorted solenoids, no shorts to ground, no shorts to power...so, another new TCM.....plug it in, and I have communication with the TCM with the Tech 2, I have a fault code for unprogrammed TCM, naturally. I flash it and BAM.....no communication.

Now I'm pissed....I break out my EFI Live and try to retrieve the calibration from the TCM and 4 out of 5 attempts I get a "no data received" and when it does, I get this calibration may be invalid....I read it, and the VIN is blank....so at this point I know in my mind SOMETHING on this truck is interrupting the flash and killing this TCM......so....I break out the benchtop programming setup and eliminated EVERY POSSIBILITY that it is something on the truck killing the TCM, I get a THIRD TCM and plug it into my benchtop setup along with the PCM....I have communication with the PCM and the TCM with my Tech 2 with the standalone harness, naturally I have a TCM code for "not programmed"......all good....I have communication....I know THAT wiring is sound, I know there are no shorts in any data lines, output devices etc because I am using a standalone benchtop programming setup...so....back to acdelcotds and flash the TCM with the benchtop harness using the MDI2....and once again, no programming errors, it completes just fine....and after the flash NO COMMUNICATION with the TCM.

Something in that calibration is bricking my new TCM's.....

So, fast forward to today....56 minutes on the phone with acdelcotds....they could see on their end where I had done the three successful flashes...they verified that calibration is the same as what it left the factory with. They had me do a vci flash on the PCM, they ran through the calibration line by line....they said, "at the end of the day, on our end, the programming is the responsibility of Allison"...he put me on hold to have another set of eyes look at everything, and he came back and said, "unfortunately their conclusion was that it must be something in the vehicle wiring, and I know that's not the case because you are using a stand-alone harness, but at the end of the day it may be something Allison has to get straight"....and just then I heard him talking to someone in the background...I hear him say, "so you heard from the guys at Allison then".....he comes back to me and says, "Allison claims that those modules on the medium duties are no longer supported by Tis2web and don't require programming....you'd think they'd put a note in the box or something...they claim you set it up with the Tech 2"

That sounded like rubbish to me. My question was then, "if that's the case, will setting it up with the scan tool eliminate the "module not programmed" fault code?" He has no clue....he assumes so....he's not Allison.

So....it all sounds implausible to ME, but at this point in time, programming it with TIS was in fact rendering the TCM useless.....my question then was, why does TIS it even allow programming? When the VIN comes up as a medium duty, why isn't that a message that pops up? Again, no clue he says....

So....there you have it....the word I get is the flash was bricking the module because it's not supposed to be flashed.....that's the story from Ac Delco....sounds implausible that this A50 can be just set up with the scan tool....so I do a little favor asking of a guy I know who worked for Allison division back a few years ago....he's going to have to do more digging, as he hasn't had dealings with any "older stuff" in a while, but he thinks the controller will INDEED have to be flashed, but that it is a calibration that is totally different from ANY calibration or OS GM uses on 2500 and 3500's and may indeed have to be done with Allison hardware/software only.

Anyone got any insight on the medium duty stuff? If I was able to get someone to read another A50 in another medium duty with EFI Live, would I be able to change the VIN and flash this medium duty A50 with it?

Just trying to get a customer back on the road. At this point, it's not about making a nickel, it's about customer satisfaction.

I would contact Lyndon at Westers Garage as he probably done enough 4500-5500 to know. I pretty sure he supplies Dorman with their tcm files. I don't think EFI will do a entire write on a A50 though.
June 23rd, 2016
ScarabEpic22

Pretty sure EFILive can do full read/flash on the A50 as per Ross' post here.

If you can find a clean, stock file with the OS you need, perhaps using EFILive to full flash the controller instead of TIS would work? I'll have to leave it up to the other guys on here, but from my research it seems this should be ok (as long as a full flash on a blank A50 TCM is all that's needed to initialize it).
June 24th, 2016
Road

Quote:

Originally Posted by ScarabEpic22

Pretty sure EFILive can do full read/flash on the A50 as per Ross' post here.

If you can find a clean, stock file with the OS you need, perhaps using EFILive to full flash the controller instead of TIS would work? I'll have to leave it up to the other guys on here, but from my research it seems this should be ok (as long as a full flash on a blank A50 TCM is all that's needed to initialize it).

Good to know. Problem solved
July 17th, 2018
beav

Quote:

Originally Posted by ScarabEpic22

Pretty sure EFILive can do full read/flash on the A50 as per Ross' post here.
...also, a 2009 TCM...

If you can find a clean, stock file with the OS you need, perhaps using EFILive to full flash the controller instead of TIS would work? I'll have to leave it up to the other guys on here, but from my research it seems this should be ok (as long as a full flash on a blank A50 TCM is all that's needed to initialize it).

I recently flashed a new A50 from the dealer with the EFI Live stock file read from the original (replaced) A50. It appears to have bricked the TCM with a U0101 and failed attempts to communicate.

After seeing a few posts stating success with flashing a new (blank) TCM via EFI Live, I then researched why mine resulted in a U0101, loss of communications (cannot read or flash), and a limp. That is when I started to see that the new TCM had to be initially flashed via Tech2.

Can anyone confirm with any certainty as to why an initial Tech2 flash would be required (or not)?

Further, I performed a read of the new TCM before anything else and it went fine, but the ctz file was 2098 KB instead of the expected 2112 KB. I'm wondering what would be missing. Does anyone know how to grab a binary from the A50?