CAN COMMUNICATION SYSTEM Open in CAN Main Bus Line (RHD Models)

DESCRIPTION

There may be an open circuit one of the V bus main lines and/or a DLC3 branch line when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is 64 Ω or higher.

Symptom Trouble Area
Resistance between terminals 6 (CANH) and 14 (CANL) of DLC3 is 64 Ω or higher.

  • DLC3 branch line or connector

  • CAN main bus line or connector

  • ECM

  • Skid control ECU (brake actuator assembly)

  • CAN No. 1 junction connector

  • CAN No. 2 junction connector

This malfunction is not related to the lines of a CAN main bus branch or to ECUs or sensor connected a CAN main bus branch.

WIRING DIAGRAM

A004KE0E02

CAUTION / NOTICE / HINT

Note


  • Before measuring the resistance of the CAN bus, turn the ignition switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work Click here.

  • Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output Click here.

  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

  • DTC check procedure: Turn the ignition switch to ON, wait at least 60 seconds,

  • After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed Click here.

Tech Tips


  • Operating the ignition 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 FOR OPEN IN CAN BUS LINES (DLC3 BRANCH LINE)


    1. Disconnect the cable from the negative (-) battery terminal.

    2. A004H5GE04
      Text in Illustration
      *1 DLC3

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D10-6 (CANH) - D10-14 (CANL) Cable disconnected from negative (-) battery terminal 114 to 126 Ω

      Note

      When the measured value is 127 Ω or higher and a CAN communication system DTC is output, there may be a fault besides disconnection of the DLC3 branch line. For that reason, troubleshooting should be performed again from How to Proceed with Troubleshooting after repairing the trouble area Click here.


    NG

    REPAIR OR REPLACE CAN BRANCH LINE CONNECTED TO DLC3

    OK

  2. CHECK FOR OPEN IN CAN BUS LINES (ECM)


    1. A004HQGE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the A33 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A33-19 (CANH) - A33-18 (CANL) Cable disconnected from negative (-) battery terminal 114 to 126 Ω

    OK

    REPLACE ECM Click here

    NG

  3. CHECK FOR OPEN IN CAN BUS LINES (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY))


    1. Reconnect the A33 ECM connector.

    2. A004KP5E04
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Disconnect the A5 skid control ECU (brake actuator assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A5-26 (CANH) - A5-14 (CANL) Cable disconnected from negative (-) battery terminal 114 to 126 Ω

    OK

    REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) Click here

    NG

  4. CHECK FOR OPEN IN CAN BUS LINES (CAN NO. 2 J/C)


    1. Reconnect the A5 skid control ECU (brake actuator assembly) connector.

    2. A004HLPE03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *b to Skid Control ECU (Brake Actuator Assembly)
      *c to CAN No. 1 Junction Connector

      Disconnect the wire harness connector from the D43 CAN No. 2 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      D43-1 - D43-12 Cable disconnected from negative (-) battery terminal 114 to 126 Ω skid control ECU (brake actuator assembly)
      D43-9 - D43-20 Cable disconnected from negative (-) battery terminal 114 to 126 Ω CAN No. 1 junction connector
      Result
      Result Proceed to
      OK A
      NG (CAN No. 1 junction connector main line) B
      NG (skid control ECU (brake actuator assembly) main line) C

    A

    REPLACE CAN NO. 2 JUNCTION CONNECTOR

    C

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 1 J/C - SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY))

    B

  5. CHECK FOR OPEN IN CAN BUS LINES (CAN NO. 2 J/C - CAN NO. 1 J/C)


    1. Reconnect the wire harness connector to the D43 CAN No. 2 junction connector.

    2. A004JJXE03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *b to CAN No. 2 Junction Connector

      Disconnect the wire harness connector from the A17 CAN No. 1 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A17-6 - A17-17 Cable disconnected from negative (-) battery terminal 114 to 126 Ω

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 1 J/C - CAN NO. 2 J/C)

    OK

  6. CHECK FOR OPEN IN CAN BUS LINES (CAN NO. 1 J/C - ECM)

    A004J4RE03
    Text in Illustration
    *a

    Front view of wire harness connector

    (to CAN No. 1 Junction Connector)
    *b to ECM

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A17-7 - A17-18 Cable disconnected from negative (-) battery terminal 114 to 126 Ω

    OK

    REPLACE CAN NO. 1 JUNCTION CONNECTOR

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 1 J/C - ECM)