Diagnosis System

MULTIPLEX COMMUNICATION: MULTIPLEX COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM

DIAGNOSIS SYSTEM

1. DESCRIPTION
The gateway ECU sets a diagnosis trouble code (DTC) if a malfunction occurs in the multiplex communication network (MPX). Techstream allows the DTC to be displayed when the tester is connected to the DLC3.





2. DLC3
The vehicle's ECU uses the ISO 15765-4 communication protocol. The terminal arrangement of the DLC3 complies with ISO 15031-3 and matches the ISO 15765-4 format.





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 Techstream to the DLC3, turn the power switch ON (IG) and attempt to use the tester. If the screen displays the message UNABLE TO CONNECT TO VEHICLE, there is a problem either with the vehicle or the tester.
If communication is normal when Techstream is connected to another vehicle, inspect the DLC3 on the original vehicle.
If communication is still not possible when the tester is connected to another vehicle, the problem is probably in the tester itself. Consult the Service Department listed in the tester's instruction manual.