CAN COMMUNICATION SYSTEM Main Body ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Main Body ECU Communication Stop Mode

  • "Main Body" is not displayed on "Communication Bus Check" screen of the intelligent tester.

  • Applies to Main Body ECU Communication Stop Mode in DTC Combination Table.

  • Power source circuit of the main body ECU

  • Main body ECU branch wire or connector

  • Main body ECU

WIRING DIAGRAM

A01CCS3E04
A01CD3EE01

INSPECTION PROCEDURE

Note


  • Turn the engine switch off before measuring the resistances of the CAN main wires and the CAN 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 doors. If any doors need to be opened in order to check the connectors, open the doors and leave them open.

Tech Tips


  • Operating the engine switch, any other switches or a door 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 determine the cause of the malfunction.

PROCEDURE


  1. CHECK CAN BUS WIRE FOR DISCONNECTION (MAIN BODY ECU BRANCH WIRE)


    1. A01CGFNE01

      Turn the engine switch off.

    2. Disconnect the connector of the main body ECU.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      G50-5 (CANH) - G50-6 (CANL) Engine switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (MAIN BODY ECU BRANCH WIRE)

    OK

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)


    1. Disconnect the connectors of the main body ECU.

      A01CF9LE01

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      4M-1 (ALTB) - Body ground Always 11 to 14 V
      4K-9 (BATB) - Body ground Always 11 to 14 V
      4A-26 (ACC) - Body ground Engine switch on (ACC) 11 to 14 V
      4M-1 (IG) - Body ground Engine switch on (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

  3. CHECK HARNESS AND CONNECTOR (GROUND TERMINAL)


    1. A01CB7FE04

      Turn the engine switch off.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      G50-1 (GND) - Body ground Always Below 1 Ω
      4A-3 (GND2) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)

    OK

    REPLACE MAIN BODY ECU Click here