2005 Vette, 6spd, 110k miles. The original E40 failed at 6 years. The replacement E40 has now failed (also at 6 years). Maybe it is just a coincidence. Maybe not. But clearly the E40 was a 1 to 2 year bridge ECM to the E38/E67 and may have not been GM's best effort. Friends in the ECM repair business say no one is repairing the E40 because of the way the PCBs are made. A quick search finds very few E40s available (at about $500 each). Those same friends say the only units available are take-out units that have been cleaned up and tested. So I asked myself if there is an alternative to either an expensive old-age ECM or having expensive yard art. Another friend in the business says he heard that someone has successfully swapped an '04 Vette 411 ECM into a '05 Vette. 1M 411s were used in so many platforms across so many years there must be a gazillion of them. Swapping E40 pins to 411 pins and loading the two 411 connectors would be a lot of work w/o a reasonable chance of success. So I have a few questions: Does anyone know if the serial and GMLAN protocols are common across those two years? What about BCM / ECM OS compatibility? Has anyone really done this and did they document it? If they did, did they need a TECH II or some such device to make the switch?