What is Mazda ETC-RELAY?

Etc relay is an electronic throttle control relay.

Relay (English name: relay) is an electrical control device. When the change of input (excitation) meets the specified requirements, the controlled quantity changes in the electrical output circuit in a predetermined step. It has the interactive relationship between the control system (also called input loop) and the controlled system (also called output loop).

This is an electronic throttle control relay.