LSA/6L80E U0101 TCM lost communication -Holden Colorado swap

[pointblank5]

seems odd that the bcm stops the trans from communicating to the ecm. typically the ecm address would 7E0, tcm = 7E2. bcm would be another address.

you could try doing a full write of a different os into the trans from say a 2011-17 commodore to see if that makes any difference.

Who did your harness/ engine mounts for you? I've got a front end pranged 2019 in the back yard for spares, my daily is a 2017.

I pulled out a conversion done originally by Formula Tech. I just had to make different engine mounts, the rest fit physically.

[pointblank5]

seems odd that the bcm stops the trans from communicating to the ecm. typically the ecm address would 7E0, tcm = 7E2. bcm would be another address.

20240415_152733.jpg

Here is a picture of the codes, do these adresses look familiar at all?
P0315 has been cleared.

0x541 is the same address as other codes like power windows etc so i assume thats the BCM.
0x7E8 must be the ECM right?

[TheMechanic]

Again, if you remove the communication lines to all other modules and have ONLY the ECM and TCM connected through the DLC given you have the 60 ohms on the CAN line then you can be sure you have another module creating this. VERY likely to be the BCM.
If not you could have a failed ECM or TCM. Also the P1682 if I remember correctly (don't have access to my SI at the moment) is an ignition power supply problem. The modules often times will get ignition power from more than one source. Any recent wiring issues or changes?
Last but not least I would disconnect and reconnect the cannon plug at the transmission. Check it for transmission fluid.

[pointblank5]

Again, if you remove the communication lines to all other modules and have ONLY the ECM and TCM connected through the DLC given you have the 60 ohms on the CAN line then you can be sure you have another module creating this. VERY likely to be the BCM.
If not you could have a failed ECM or TCM. Also the P1682 if I remember correctly (don't have access to my SI at the moment) is an ignition power supply problem. The modules often times will get ignition power from more than one source. Any recent wiring issues or changes?
Last but not least I would disconnect and reconnect the cannon plug at the transmission. Check it for transmission fluid.

Yes the p1682 was a power problem that I solved, hence the permanent status of the code.

I have had the trans plug on and off about 5 times verifying the wiring goes everywhere it's supposed to. Everything checks out positively.

Yes, lots of recent wiring changes, being that the vehicle the engine and gearbox came from was a pre-facelift colorado with a different type of ECM to the current vehicle. Gearboxes were both 6L50s, and most wiring colours are the same, once I verified by pin # description.

[Tre-Cool]

is the tcm os the original 2012 from the 6l50e?

yes 7e8 is the ecm. been a while since i logged can data directly.

probably need to map out the id's for all the can modules, the main difference between a pre facelift model will be the electric power steering, if it's like the vf it might also be on the can link, but GM is pretty strict to keeping ID's the same across the models. It would be a huge shit show if devices used different addresses across models.

[blindsquirrel]

Yeah, the world would fall apart if GM did something so stupid as having twenty-two possible door module part numbers for a single vehicle, each of which requires its own bespoke calibration...

screenshot.18-04-2024 17.24.14.png

Not the same thing, sure, but never rule out GM doing something stupid for no reason that creates other problems later.

[pointblank5]

is the tcm os the original 2012 from the 6l50e?

yes 7e8 is the ecm. been a while since i logged can data directly.

probably need to map out the id's for all the can modules, the main difference between a pre facelift model will be the electric power steering, if it's like the vf it might also be on the can link, but GM is pretty strict to keeping ID's the same across the models. It would be a huge shit show if devices used different addresses across models.

The TCM OS is for a 6l90. The main OS number matches a VF HSV 6l90 equipped car, the segment numbers are different so it's probably from a camaro aswell.

[Tre-Cool]

im thinking when u say pre-facelift & 2012 colorado, Im guessing it was the bosch based ecu, not the later gm/delco e98 ecu?

prob good bet the bcm was a lot dumber on that model compared to 2013 onwards models.

Can you exclude the bcm from the can signal for testing to see if everything is happy?

[pointblank5]

im thinking when u say pre-facelift & 2012 colorado, Im guessing it was the bosch based ecu, not the later gm/delco e98 ecu?

prob good bet the bcm was a lot dumber on that model compared to 2013 onwards models.

Can you exclude the bcm from the can signal for testing to see if everything is happy?

Yes mate exactly, had the Bosch ECM originally in the 2012.
I can try that, but seeing as it's BCM code I'm getting, is that going to prove anything? As the gearbox/engine combo was happy together before

[blindsquirrel]

What BCM code? That hasn't been mentioned before. You said it was only a U0101 in the ECM and no codes in any other module in the vehicle.

[pointblank5]

What BCM code? That hasn't been mentioned before. You said it was only a U0101 in the ECM and no codes in any other module in the vehicle.

Maybe I have assumed wrongly, but the fact that the old BCM being installed cleared the u0101 code, and the 0x541 prefix to the u0101 when active told me it was a BCM code?

[pointblank5]

UPDATE;

I have tried segment swapping the T43 segments from a 2017 HSV GTSR (LSA + 6L90). The main OS number for the transmission is the same- 24264923, however the segment numbers are quite different, my original tune are (24265266, 24265267, 24265268), the newer HSV (92283046, 92283056, 92283066).

Any way they swapped in fine, when i wrote the T43 calibration and tried everything again - the trans fluid temp started reading correctly on the dash, the 0x541 U0101 code was gone. However it still didnt shift, and had codes 0x7E8 P0700, 0x7EA U0100 active instead. I also tried every combination of swapping each segment in alone, in pairs etc. But no good. - different weird behaviour each time.
So this tells me the wiring is correct, and that the issue is a T43/BCM comms issue, agree?

I am working on trying to get a look at a tune file from a known working similar setup - they are around and can be done. Just not very common.

If anyone has any suggestions or knows of any tunes with the same T43 main OS number so I can try some different segment swaps, please let me know.

[pointblank5]

Well...
After going on a wild goose chase checking my wiring for 5 days...
It turns out the answer was a 2014 camaro trans system segment swap.
That managed to bridge the gap between communicating with the 2013 camaro ECM, and the 2019 Colorado BCM.

Thanks for all the replies and suggestions

[TheMechanic]

Well...
After going on a wild goose chase checking my wiring for 5 days...
It turns out the answer was a 2014 camaro trans system segment swap.
That managed to bridge the gap between communicating with the 2013 camaro ECM, and the 2019 Colorado BCM.

Thanks for all the replies and suggestions

Can you go into a little more detail on what exactly you did you get these to be happy with each other?

[pointblank5]

Can you go into a little more detail on what exactly you did you get these to be happy with each other?

I segment swapped the transmission system segment with the one from a 2014 camaro zl1 file.