R35 GTR Motec. TCM programming issue

2014 R35 with your Motec package.

Using ecutek for the TCM

The engine is up and running on the motec. I have no faults of any kind other than the TCM fault. (Form won't let me attach Photo.)

The issue is I cannot program the TCM with the Motec plugged in. I receive the error message "This ROM file is the wrong size for the selected ECU type". I also cannot read or clear codes. The GTR OBD mode is set to not in use in the motec during the programming attempt. But I can program the TCM just fine with the factory ECU plugged in. I can also read and clear codes. This is repeatable on both sides.

I can only assume that whatever is the cause of this, is also the cause of the TCM fault that is shown in the motec resulting in the transmission not going into gear.

Things I have tried.

I sent my Motec package "startup tune" to Motec support. They said that they do not see any reason the package would cause the problem.

I ask Ecutek if there is anything I am missing when trying to program, and they said it should be pretty straight forward.

I switched out the TCM for another licensed TCM from a running car, same exact issue occurs.

I looked over all the wiring and connectors, I found no issues. Even so, I'd find it hard to believe that if there was an issue with wiring that the factory ECU would not also share the same issue.

I suspect ECUTek requires the OEM ECU even with tuning the TCM. Can you temporarily install the OEM ECU while doing the TCM Setup/Programming, then switch back to the MoTeC ECU?