My understanding with the ECU's is when fitting or replacing the ECU, The ECU must be removed from the Holden Data base and new one Recorded to Data base, Also coded and linked to your vehicle, this is what Holden told me when my VZ had ECU issues.
I am a Mechanic but have since left trade, also spent a few years spinning spanners for Holden before the Alloytec's were released, And was happy with the reasoning Holden gave me about the ECU etc... Since new ECU fitted car has never ran better as they loaded all the program updates into it