In the teaching of PID control actions, it is customary to present an analysis of the open loop effects of PID actions. The closed loop effects have been observed by launching multiple simulations and analyzing their results. From our teaching experience on this topic, this way of explaining the effects of PID actions in a close loop is complex and confusing for students. However, this paper proposes an improvement for this topic's elucidation. This development is based on a mathematical and graphical closed loop analysis for a general system with each of the PID actions as a teaching aid. These teaching aids were performed as an additional tool for improving the comprehension of PID actions' effects in a closed loop. Also, those analyses are useful for the manual tuning of PID constants.