ECM and TCM give and take various data through CAN communication each other. 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 drivers of the occurrence of TCM related problem. Therefore if power train related problem happens, Engine check lamp turns ON to let drivers recognize the occurrence of power train system (A/T system) related problem.

P0701 is set when ECM detects TCM problem through CAN communication. Check whether TCM operatures or not.