GM truck TCMs in HMMWVs

[Westo]

I have an M1114 and recently found that my tcm has a bunch of burnt out components on the board. The part number listed in the TM for my truck is the same as a GM part used on 6.5 turbo trucks with the 4l80e. If I get one of these units and replace the EPROM with the one from my TCM, will it work?

The TCM part number in question is 16196390.
Parts I found that seem to be a match/rebuilt version of it are BSE 390 and CARDONE 73-80106.

 

[Mogman]

It looks like it would work, the only civy TCM I have had tested was a 16147609 and it worked fine.
None of the rebuilt units come with an EPROM and all I have seen have a core charge.

 

[Mogman]

I can read/write the OEM EPROMs but Eastern Surplus has them pretty cheap, I cannot write to those modules as they are actually PROM not EPROM but they work the same.
Yours is probably OK but if not it's not a big deal..

Eastern Surplus

 

[Westo]

It looks like it would work, the only civy TCM I have had tested was a 16147609 and it worked fine.
None of the rebuilt units come with an EPROM and all I have seen have a core charge.

Was this in a 6.5 truck? The part I was looking for is relatively hard to find, so I wonder if that one would work for mine too. That part number seems to have been in 6.2 GM trucks. With the EPROM stuff, I'm assuming I could just drop in the one out of my old TCM, although I don't know if it also died.

 

[Mogman]

It was tested in a 6.5L turbo truck, unless modified no 6.2L HMMWV had the 4L80E
The reason the 6.2L civy TCM will work is because those trucks had a mechanical IP like all HMMWVs have, at some point when the civy trucks all went to electronically controlled IPs the TCM would change because that engine has an ECM (engine control module).
Not saying the one you found will not work as it appears to be identical but at some point I think they evolved to the point the TCM would not work without the ECM
The part number on your TCM should be a good number.

I would also be concerned that something external may have fried the TCM, I would look long and hard at all the voltages being fed into the TCM before plugging in another one.

 

[Westo]

It was tested in a 6.5L turbo truck, unless modified no 6.2L HMMWV had the 4L80E
The reason the 6.2L civy TCM will work is because those trucks had a mechanical IP like all HMMWVs have, at some point when the civy trucks all went to electronically controlled IPs the TCM would change because that engine has an ECM (engine control module).
Not saying the one you found will not work as it appears to be identical but at some point I think they evolved to the point the TCM would not work without the ECM
The part number on your TCM should be a good number.

I would also be concerned that something external may have fried the TCM, I would look long and hard at all the voltages being fed into the TCM before plugging in another one.

Aside from looking for ground on the ground pins and 12v on the ignition and battery feed pins, are there any other ones I should look at? I'm not sure what normal voltage is for the sensors and other pins.

 

[Mogman]

Aside from looking for ground on the ground pins and 12v on the ignition and battery feed pins, are there any other ones I should look at? I'm not sure what normal voltage is for the sensors and other pins.

Don't worry about any other "pins" unless you get a code, then check that circuit.

 

[Westo]

I checked all the connections again, and wanted to post some of the ones I'm not sure about with higher voltages to see if they seem correct. These are readings at the TCM connector (no TCM installed) with the truck on.

D, Shift Solenoid B: 14v
E, Shift Solenoid A: 14v
U, Check Trans Lamp: 12v
X, TCC Solenoid: 14v

Most of these just go into the transmission on the wiring diagram, and I'm not familiar with how they operate, so I'm not sure if the voltage is normal. Nothing here seems too exceptional, but since I haven't found any other reason for the TCM to explode I figured I'd see if these sound right.

 

[Westo]

Finally got around to putting in the new TCM and it seems to work. Didn't immediately blow up, so probably means the last one failed on its own. Trans light stays on when run switch is on and it will go into diagnostic mode, but it only flashes 12 over and over again. Troubleshooting guide does say that an EPROM error might be "able to flash DTC 12/51, but not enable serial data". 51 is the code for bad EPROM, so I'm not sure if the use of / here means 12 AND 51 or 12 OR 51.

 

[Mogman]

The light stays on when running? you did not make it clear if the run switch was just on or the engine was running...

 

[Westo]

The light stays on when running? you did not make it clear if the run switch was just on or the engine was running...

Yes, on while running too.

 

[Westo]

Found the issue. I put it in diagnostic mode before I ran the engine the first time, but I ran it for a while and tried again and got it to work properly and give me a code.