P2438 - Secondary Air Injection System Air Flow/Pressure Sensor Circuit High on Bank 2

I had this trouble code come up recently and have been doing quite a bit of testing. I have a Hewitt Gen II bypass kit installed on this vehicle as well. I am going to replace the SAI Switching Valve, since even with the Hewitt bypass kit installed, the ECM still looks for data from the internal pressure sensors of the switching valve...but before I replace the expensive part, I want to make sure I don't have a wiring issue on the Bank 2 connector circuit, such as a short or open on the signal wire. Ground and 5V reference tests good on the Bank 2 connector to the Secondary Air Injection Switching Valve.

When I test the "Signal" wire for bank 2 on the SAI switching valve, key on engine off (KOEO), and the connector connected to the valve, I get 2.6V...but when I test the "Signal" wire with the connector DISCONNECTED from the switching valve, KOEO, I get 38mv (basically a ground reading).

On the Bank 1 signal wire I get the same readings when the connector is connected to the switching valve, but when the connector is disconnected from the valve I get 4.4V on the signal wire on Bank 1. The CEL code is for Bank 2, so is the 38mv reading that I'm getting on the Bank 2 signal wire (when the connector is DISCONNECTED) mean I have a short...especially since the reading is so different from the signal wire on Bank 1?

I don't have much experience testing and finding wiring faults, so I'm trying to figure out how to test this circuit properly to make sure my wiring is good before I replace any parts.
Thanks!