ECM and TCM transives various data via CAN communication. When the problem of TCM related sensor (input speed sensor, output speed sensor, inhibiter switch, etc.) and actuators (transaxle solenoid valve, etc.) occurs, gear is fixed at 3rd gear position. However, there is no alarming device such as "TCM warning lamp" which notifies the occurrence of TCM related problem to drivers. Therefore ,if powertrain related problem is detected, engine check lamp turns ON and notifies drivers.