Sorry to hear...
Sorry for all your trouble Tony...
One of the first and foremost reasons I chose the Ecotec platform was it's simplicity... It utilizes a "Speed Density" system for driveability. No CANBus... Parts are local and cheap as cheap gets. A little bigger than most jap motors, but solid.
"Speed Density" for those who do not know typically refers to the operation of an engine using an estimation of airflow based on pressure, temperature and some idea of the engine's volumetric efficiency... Intake Air Temp, Map, Wideband O2, TPS, Knock Sensor... Simple as simple gets and an absolute breeze to tune with HP Tuners or EFI Live... It is not as precise as having a MAF, but very tuneable none the less. Nothing you would notice as far as driveability is concerned. ECU's??? They are 50.00 to 75.00 on Ebay.
I wish I had some answers for you... After 25+ years in the Automotive Industry I've had my share of ghosts and gremlins... Chrysler is notorious for their CANBus system failing to "go to sleep" and running a battery down overnight. Could be the body control module, could be the a/c control module, could be the Audio unit, could be the cluster... etc, etc...
I used to have to unplug a fuse at a time then go from module to module until the CAN went to sleep.... Then it was still a crap shoot as to whether or not it was fixed... The manual used to state at the end of the diagnostic tree... "Replace with know good part and retest"... Hahahahaha... Yeah, like I had a $1000.00 BCM just layin around.
I would not doubt it being the ECU... Then again it may not be... I think you are on the right track with the VATS... I'll tell ya, this Abarth swap of your is WAY more than I'd ever attempt... Hope you get it figured out...
And to think, I gave up working on cars to move over to Access Control... Now I spend my days in deafening high rise mechanical rooms installing and wiring control panels...
:mallet: