Various teaching methode have been applied to improve students' competency and performance.This research focuses on applying problem centered group (PCG) teaching methode to improve students' competency.The study uses one group time series design quasi-experiment by giving a treatement to the students and comparing students' competency before and after the treatement. The population was mechanical engginering student majoring in automotive electrical subject, and the sample was the 5th semester students of the same major. The result shows that by applying problem centered group (PCG) teaching method,the students' competency in describing automotive eleectrical system operation significantly improves and there is significant difference between students' competency before and after applying PCG.