Anti Theft Relearn using Scan DVT on E38

[Turbosaurus]

E38 ECM in 2015 Camaro LS3/TR6060
Serial: 86K25176TUYH
OS: 12658778

Backstory:
Obtained two identical 2015 Camaro 1LEs with LS3/TR6060; one wrecked with good drivetrain, the other a theft with no engine/transmission. Wrecked car runs and drives with no MIL and no DTCs. Downloaded cal file out of ECM for safe keeping. Pulled engine/trans/E38 with engine harness and put into theft car. Changed VIN # in ECM to same as car.

Issue:
Car would not start (no crank) and “Service Theft Deterrent System” shows on DIC along with security indicator lamp. Scan with V2 shows P0513 & P1631 DTCs. According to GM Service Manual: P0513 is set when “The calculated response from the BCM does not equal the calculation performed by the ECM”, and P1631 is set when “The ECM receives incorrect immobilizer data from the BCM”. Okay, so I need to get the ECM and the BCM on the same page of the hymnal. Not totally unexpected.

Actions attempted:
Opened 7.5 Tune and checked the VATS parameters:
{G1204} VATS Enable Yes
{G1205} VATS Auto learn Enable No
{G1206} VATS Required To Run No
{G1209} VATS Mode No
{G1210} VATS Type Type 2
{G1211} Remote Start Allowed Yes
{G1214} Relearn Count 3
{G1215} Relearn Timer 600
{G1216} Theft Relearn Password No

(Compared the above with a stock ’14 Camaro LS3/E38 and all were the same. Wondering if they should be revised to clear the current conditions? i.e. {G1205}, {G1209} & {G1216} = Yes?)

Attempted the ignition cycle method of relearn (3 cycles/600 seconds “on”). Failed to clear “Service Theft Deterrent System”.

Attempted to use DVT function Anti Theft Relearn though I could not find any documentation on the procedure. Selected Activate and Relearn. Nothing happened immediately, so cycled ignition off/on and “Service Theft Deterrent System” DIC message disappears and security indicator lamp goes out. Attempted to start but still would not crank. Attempted the cycle method of relearn (3 cycles/600 seconds “on”). Deactivated the DVT function. “Service Theft Deterrent System” immediately shows on DIC along with security indicator lamp.

Used the Tune tool to add VATS Delete patch and reflashed. Engine starts and runs, but still have “Service Theft Deterrent System” DIC message and security indicator lamp lit. Prefer to have no security warnings on DIC, and would rather not have to rely on a dealer to reset the ECM/BCM modules.

Questions:
What is the correct procedure to use with the DVT Anti Theft Relearn so that the ECM will accept and learn a new security code from the BCM? If the ignition cycle is required, what is the correct on/off times? Should the ignition be cycled to the start position each time?

Thanks in advance for your feedback.