An Embedded System is an electronically controlled system combining hardware and software. Many systems used in actual life such as power plant, medical instrument system and home appliances are embedded system. However the studies related to embedded system test is not sufficient. Especially, in embedded system, it is necessary to develop test technique to detect faults in interaction between hardware and software in embedded system. In this paper, we propose a test data selection technique using a fault injection technique for the interaction between hardware and software. The proposed test data selection technique first simulates behaviors of embedded system to software program from requirement specification. Then hardware faults, after being converted to software faults, are injected into the simulated program. And finally, we select effective test data to detect faults caused by the interactions between hardware and software. We apply our technique to the Digital Plant Protection System and evaluate the effectiveness of the selected test data through experiments.