HD3SS3220: CC Detected Device Attachment (ID Pin)

Part Number: HD3SS3220

Hello,

I was having a problem with the USB Type-C connector only working in one orientation when the HD3SS3220 was configured as a DFP. The issue was that I had the VBUS_DET pin directly tied to the system 5V supply, without using a power switch after CC detection. I intend to drive the !EN pin of a TPS25910 using the HD3SS3220 ID pin, see the attached image. 

From what I understand:

1. Initially, nothing is connected to the HD3SS3220 (DFP). 
2. The 5V output from PCB1 will be disabled by the TPS25910.
3. The 5V output from PCB1 will be enabled using the ID pin of the HD3SS3220 one CC pin detection is made.

How can the HD3SS3220 on PCB2 advertise that it is configured as a UFP if it is unpowered when a connection is made? Have I misunderstood something?

I look forward to your comments.

Thanks.