Controller for vehicle-mounted component

A controller for a vehicle-mounted component comprising:

• an automatic transmission that reduces a rotation of an engine and outputs the rotation at an output shaft;
• a shift position detector that detects an effective shift position of the automatic transmission;
• a shift position switching unit that switches the effective shift position of the automatic transmission;
• a parking switching unit that mechanically locks the output shaft of the automatic transmission when the shift position switching unit switches the effective shift position in a parking position;
• and
• a shift position switching controller that controls the shift position switching unit, a current supply thereto being substantially stopped when the engine is stopped;
• a memory device that memorizes the effective shift position at a timing when the shift position switching controller stops being energized;
• and
• a vehicle-mounted component controller that prohibits an operation of a vehicle-mounted component when the effective shift position memorized in the memory device is not in the parking position while the current supply to the shift position switching controller is stopped.