An electrical control system having a primary microcontroller, a secondary microcontroller, a slave IC, and a communication IC is provided. The communication IC sets a fault line to a first logic level indicating that an overvoltage condition has been detected in a battery cell. The secondary microcontroller sends a message to the primary microcontroller via a communication bus indicating that the overvoltage condition has been detected in response to the fault line having the first logic level. The primary microcontroller determines that both the message from the second microcontroller was received and the fault line has the first logic level to confirm that the communication bus is functioning as desired and that the secondary microcontroller is functioning as desired.