Function detection system and method for electric-controlled unit

The invention discloses an electronic control unit (ECU) function detecting system, which comprises a signal simulation unit used for generating external sensor signals needed by an ECU in a simulating way, the ECU connected with the signal simulation unit and used for interchanging data information with the signal simulation unit, a controller connected with the signal simulation unit and used for detecting the function of the ECU according to the data information of the signal simulation unit and the ECU. The function detecting system can judge if the ECU has fault in such a way that hardware is utilized to simulate the running environment of the ECU and the controller is used for detecting the running condition of the ECU. The invention can accurately detect the function of the ECU and has the advantages of simple structure, low cost, and the like.