on v1002 and P3dV4.5hf3
When testing caution logic, I noticed when moving FLT CONTROL panel's A or B FLT CONTROL switches to OFF or STBY RUD, the related (A or B) Hydraulic system's both PUMP will show LOW PRESSURE.

According to FCOMv2 13.20, A and B hydraulic system pumps:
Pressure switches, located in ED and EMDP output lines, send signal to LOW PRESSURE light .

And 13.10 Flight Control Panel (1) FLIGHT CONTROL Switches:
Closed flight control shutoff valve isolating a/e/r from associated hydraulic system pressure.