I want to know what does Auxiliary input status (PID 1E) and Auxiliary input / output supported (PID 65) OBD2 PID mean. Do they tell me whether my car is in the Aux mode (while I am listening to the radio)? Case 1: I am sitting in the car, listening to the radio. Key is in the Aux mode. Will I get any readings on hitting these PIDs? Case 2: I am driving my car, listening to the radio. Will I get any readings now? Key is not in Aux mode now obviously.
From the Wikipedia page on OBD-II PIDs. PID 1E designates if the Power Transfer Output (PTO) is active or not. PID 65 is the sister PID to 1E designating if 1E means anything, supported or not.
A PTO is a device that attaches to an engine/transmission that does other work besides driving the vehicle forward. For example a dump truck commonly had a hydraulic pump that engages with a lever on the transmission to drive the hydraulic ram for the dump bed. Another example is that bucket trucks sometimes called cherry pickers will have a hydraulic pump in the belts of the engine to operate the bucket.