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.

  • Main body ECU branch wire or connector

  • Power source circuit of main body ECU

  • Main body ECU (Multiplex network body ECU)

WIRING DIAGRAM

A01NCS2E01
A01NCZSE01

INSPECTION PROCEDURE

Note


  • Turn the power switch off before measuring the resistances between CAN bus main wires and between CAN bus branch wires.

  • Turn the power switch off before inspecting CAN bus wires for a ground short.

  • After the power switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.

  • Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the power 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.

Tech Tips


  • Operating the power 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 may help determine the cause of the malfunction.

PROCEDURE


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


    1. Turn the power switch off.

    2. A01NH84E01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Main Body ECU)

      Disconnect the main body ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F13-14 (CANH) - F13-13 (CANL) Power 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. A01NFKDE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Instrument Panel Junction Block)

      Disconnect the instrument panel junction block connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      2F-40 (BECU) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

  3. CHECK HARNESS AND CONNECTOR (GROUND TERMINAL)


    1. A01NFKDE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Instrument Panel Junction Block)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2D-6 (GND1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here