U1002

DTC U1002 Lost Communication with Gateway Module

DESCRIPTION

DTC Detection Condition:

- The gateway ECU will store this DTC when no signals can be received from the ECUs that have been memorized as those that are connected to the CAN No. 2 bus.
- When the gateway ECU receives response signals from the ECUs connected to the CAN No. 2 bus, the gateway ECU recognizes and memorizes that the ECUs are connected to the CAN No. 2 bus. Based on this memorized data, the gateway ECU monitors for malfunctions in the ECUs connected to the CAN No. 2 bus when communicating with those ECUs. If the gateway ECU cannot receive response signals from the ECUs that have been memorized as those connected to the CAN No. 2 bus, the gateway ECU determines that a malfunction exists.

Wiring Diagram:

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INSPECTION PROCEDURE

NOTE:
- Turn the engine switch off before measuring the resistances of CAN bus main wires and CAN bus branch wires.
- After the engine switch is turned off, check that the key reminder warning system and light reminder warning system are not in operation.
- Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the engine switch, any other switches, or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.

HINT:
- Operating the engine switch, any switches, or any doors triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
- Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below will help to determine the cause of the malfunction.