A simple set-up for quick and purely electrical QC testing of knock sensors is described in this paper. The main goal is to measure the “impedance” frequency response function of the sensors. The advantages of the test procedure described in this paper are as follows: Simple “pseudo” one channel measurement, from the operator's point of view. Electrical testing, i.e. no need for shakers, power amplifiers, elaborate fixtures etc.. Pulse excitation, thus very fast - in the order of 100ms for one measurement test. No averaging needed. Standard frequency response function display is used, i.e. no complex postprocessing needed. The only requirement is a small junction box with the necessary transformer and some electronics. The power supply for the junction box is the analyzer. The testing method can be extended to other types of transducers such as accelerometers.