Rapid increase of embedded systems in electronic and mechanical control systems requires reliable and error-free embedded software. State-based testing methods like FSM are usually used to assure the reliability of embedded software. However, because of possibility of explosion of test cases, only partial test cases are considered in practical tests, which cannot guarantee that all the possible errors are investigated. This study proposes a test procedure based on failure mechanisms that may occur in embedded systems, which can not only assure that certain kinds of possible errors are detected but reduce the testing time. The proposed procedure is applied to vehicle air control system.