To attain the requirement of ISO26262 standard, the POST for automotive MCU needs to achieve high Latent Fault (LF) metric (>90% for ASIL D) within limited test application time (TAT). In this paper, we propose a new DFT technique named Fault-Detection-Strengthened (FDS) method to enhance the effect of test pattern reduction of the multi-cycle test for shortening the TAT of POST, and develop an original in-house tool named FVP-TPI (Fault Vanishing Point-TPI) to implement the FDS method to automotive MCU. The evaluation results on a latest commercial automotive MCU (62M gates) confirm the effectiveness (test volume compaction) and the practicability (smaller hardware overhead, shorter period of DFT) of the method.