HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS GENERAL INFORMATION




  1. DESCRIPTION


    1. Each system data and the Diagnostic Trouble Codes (DTCs) can be read from the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the intelligent tester to check for malfunctions and perform repairs.

  2. CHECK DLC3


    1. A015ZDXE16

      The vehicle ECUs use ISO 15765-4 communication protocol. The terminal arrangement of the DLC3 complies with ISO 15031-2 and matches the ISO 15765-4 format.

      Symbol Terminal No. Name Reference Terminal Result Condition
      SIL 7 Bus "+" line 5 - Signal ground Pulse generation During transmission
      CG 4 Chassis ground Body ground 1 Ω or less Always
      SG 5 Signal ground Body ground 1 Ω or less Always
      BAT 16 Battery positive Body ground 11 to 14 V Always
      CANH 6 CAN "High" line 14 - CANL 54 to 69 Ω Engine switch off*
      Battery positive 6 kΩ or higher Engine switch off*
      4 - CG 200 Ω or higher Engine switch off*
      CANL 14 CAN "Low" line Battery positive 6 kΩ or higher Engine switch off*
      4 - CG 200 Ω or higher Engine switch off*

      Note

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