G4: Check Switch P/N

With EM047 disconnected, measure the resistance between EM047/00K & EM047/00J.

With the selector lever at P & N is the resistance < 0.5 ohms?
With the selector lever at R, D, 4, 3, 2 is the resistance > 50K ohms?

Yes
Go to G5 G5: Check Harness Signal Continuity

No
Renew the rotary position switch & test the system for normal operation.