Mind you, I'm a Nissan guy and not Infiniti and it's possible Infiniti did something completely off the wall with your particular ride, but I've never heard of needing to flash an ECM in order to flash a TCM. They're separate entities. If the ignition won't turn on without a live ECM, that's different, but that's a power issue and not programming. Jump the ignition relay. I have no idea about the zero draw, either. We program ECM's every day with a charger attached to support the IPDM, which will turn on fans, lights, and all kinds of "safe mode" crap while the ECM is offline being programmed. As long as the voltage stays above 12.0V, there's never any issue.