A numerical study on deformation piezoelectric sensors is described in this study. Major objectives of this research are to compare the impacts of direct current voltage on piezoelectric structure, the effects of direct current voltage on the resonance frequency of piezoelectric knock sensors, and the effects of these parameters on the sensitivity and accuracy of the sensors. The impedance properties of the transient structure are studied under different engine operating conditions and in relation to various forms of sensor damage. Determining the degree of damage sensors and the prediction quality of the piezoelement within the sensor may be accomplished by measuring material flaws and fluctuations in material coefficients that are connected to the frequency characteristic of the sensor. To some extent, the preceding can be used in the calculations of several structural parts of knock sensors. On a prototype knock sensor, ranges of modes were tested using piezoelectric elements with varying numbers of cracks. In this work, it has discussed seven scenarios of frequency analysis to examine the piezoelectric in engine knock sensor with different electricity modes of operation. These scenarios include the engine normal operation mode, start engine operation mode, and different frequency of operation mode (2Hz, 200Hz, 2KHz, 20KHz, 200KHz).