2012 chevy traverse, 3.6 - Starts then shuts down, NO CODES argggggggh

Had a shop call me on a 2012 traverse, runs then shuts off. Went through everything thing and the only code was P062F. Car runs then shuts down. No immobilizer light on. No codes. Ecm software needed updating so went ahead and updated. NO CHANGE.
Has anyone come across this code before?  Service info says ecm replacement.  I need better direction before become a parts changer!Lol

DTC P062F
 -  Control Module Long Term Memory Performance

Circuit/System Description

The internal fault detection is handled inside the fuel pump flow control module (FPCM). No external circuits are involved.

Check the Fuel Pump Control Module for good power and ground before replacing.  After replacing, the module will need to be programmed with SPS2.
 

Which module set the P062F?

The only time I've seen that code was on a '12 Acadia that had a no crank complaint. P062F was set along with a list of O2 codes:

 

I ultimately found a failing battery. Cranking voltage would go below 6V at times. Voltage drops were good. TSB #12-06-04-001 suggested the same:

 

I'd monitor PCM powers and grounds during the shutdown, if you haven't already. Don't know the mileage, but a 2012 is old enough to have had the engine out at least once for chains. That makes the main block ground, the rear cylinder head ground and the fuse box connections suspect. If the powers and grounds check, it's ECM time.