Some vehicles (equipped with the Electrical supply unit (ESU) BCKA-67-5Z0B) may exhibit that DTC B2002:49 [BODY CONTROL MODULE (BCM) - Electrical supply unit (ESU) internal malfunction (No warning/indicator light ON)] will not clear with the Mazda Modular Diagnostic System (M-MDS). This is caused by improper control software of the ESU. To eliminate this concern, the control software of the ESU has been modified.