DTC U1002: Lost Communication with Gateway Module (MS Bus): Description

The main body ECU stores this DTC when no signals can be received from the ECUs that have been memorized as those connected to the CAN MS bus.
When the main body ECU receives a response signal from the ECUs connected to the CAN MS bus, the main body ECU recognizes and memorizes that the ECU is connected to the CAN MS bus. Based on this memorized data, the main body ECU monitors for malfunctions in the ECUs connected to the CAN MS bus when communicating with those ECUs. If the main body ECU cannot receive response signals from the ECUs that have been memorized as those connected to the CAN MS bus, the main body ECU determines that a malfunction exists.
If 2 or more DTCs are output during the DTC check, one side of the CAN branch wire may be open (one side of the CANH [CAN branch wire]/CANL [CAN branch wire] of the ECU and/or sensor is open).

DTC Code	DTC Detection Condition	Trouble Area
U1002	Lost communication with the gateway module (MS bus).	MS bus circuit Main body ECU (instrument panel junction block assembly) CAN main wire or connector Tire pressure monitor ECU CAN branch wire or connector Back door motor unit (power back door ECU) CAN branch wire or connector* Main body ECU (instrument panel junction block assembly) Tire pressure monitor ECU Back door motor unit (power back door ECU)* No. 3 junction connector CAN junction connector