Multiplex Communication System Diagnosis System

The network gateway ECU controls the functions of the multiplex communication system of the vehicle. Data of the multiplex communication system and the Diagnostic Trouble Codes (DTC) can be read through the Data Link Connector 3 (DLC3) of the vehicle.

The vehicle's ECU uses the ISO 15765-4 format for communication protocol. The terminal arrangement of the DLC3 complies with ISO 15031-03 and matches the ISO 15765-4 format.

1. If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.
   

HINT:

Connect the cable of the intelligent tester to the DLC3, turn the engine switch on (IG) and attempt to use the tester. If the display indicates that a communication error has occurred, there is a problem either with the vehicle or with the tester.

1. If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle.
   
2. If communication is still not possible when the tester is connected to another vehicle, the problem may be in the tester itself. Consult the Service Department listed in the tester's instruction manual.