From my experience I can tell you that the low voltage, ABS module and the DTC codes for ABS and ECU #2 are connected and caused by low voltage. Your battery may be going out. I had the same DTCs when it got really cold and my battery was old.
To clear the ECU #2 code you will have to first clear all codes from ABS module. So you will have to clear the codes at least twice.
As for the flap and the TPS that may be related and it's a bad news as the manifold flap must be replaced and it is pretty expensive.
Just clear the codes and then see if the TPS and manifold flap comes back.