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

DESCRIPTION

There may be an open circuit in the CAN main bus line and/or the DLC3 branch line when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is 69 Ω or higher.

Symptom Trouble Area
Resistance continuity between terminals 6 (CANH) and 14 (CANL) of the DLC3 is 69 Ω or higher.

  • CAN main bus line or connector

  • CAN LH Junction Connector

  • CAN RH Junction Connector

  • DLC3 branch line or connector

WIRING DIAGRAM

A01635BE13

INSPECTION PROCEDURE

Note


  • Turn the engine switch off before measuring the resistance of CAN bus main wires and CAN bus 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 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 engine switch, any switches, or any doors triggers related ECU and sensor communication with the CAN. This communication will cause the resistance value to change.

PROCEDURE


  1. CHECK DLC3


    1. Turn the engine switch off.

    2. A0161HNE24

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

      Standard Resistance
      Tester Connection Switch Condition Specified Value Result
      J21-6 (CANH) -J21-14 (CANL) Engine switch off 108 to 132 Ω A
      J21-6 (CANH) - J21-14 (CANL) Engine switch off 133 Ω or higher B

      Note

      When the measured value is 132 Ω or higher and a CAN communication system diagnostic trouble code 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 Click here after repairing the trouble area.


    B

    REPAIR OR REPLACE DLC3 BRANCH LINE OR CONNECTOR (CANH, CANL)

    A

  2. CHECK FOR OPEN IN CAN BUS MAIN WIRE (CAN BUS CHECK)


    1. Perform "CAN Bus Check" using the intelligent tester Click here.

      Result
      Specified Condition Proceed to
      "Engine" and "ECT" only are not displayed A
      "Gateway" only is not displayed B
      Others C

    B

    CHECK FOR OPEN IN CAN BUS MAIN WIRE (GATEWAY ECU - CAN LH JUNCTION CONNECTOR) Click here

    C

    CHECK FOR OPEN IN CAN BUS MAIN WIRE (ECM - CAN LH JUNCTION CONNECTOR) Click here

    A

  3. CHECK FOR OPEN IN CAN BUS MAIN WIRE (ECM - CAN LH JUNCTION CONNECTOR)


    1. A015Z5SE06

      Turn the engine switch off.

    2. Disconnect the ECM connector (A6).

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

      Standard Resistance
      Tester Connection Switch Condition Specified Value
      A6-14 (CANH) - A6-13 (CANL) Engine switch off 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (ECM - CAN LH JUNCTION CONNECTOR)

    OK

    REPLACE ECM Click here

  4. CHECK FOR OPEN IN CAN BUS MAIN WIRE (GATEWAY ECU - CAN LH JUNCTION CONNECTOR)


    1. A015Z77E23

      Turn the engine switch off.

    2. Disconnect the gateway ECU connector (J76).

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

      Standard Resistance
      Tester Connection Switch Condition Specified Value
      J76-17 (CA1H) - J76-18 (CA1L) Engine switch off 108 to 132 Ω

    NG

    RECONNECT CONNECTOR Click here

    OK

    REPLACE GATEWAY ECU Click here

  5. RECONNECT CONNECTOR


    1. Reconnect the gateway ECU connector (J76).


    NEXT

  6. CHECK FOR OPEN IN CAN BUS MAIN WIRE (CAN RH JUNCTION CONNECTOR - GATEWAY ECU)


    1. A0161BKE23

      Disconnect the CAN main bus line connector (J84) from the CAN RH junction connector B side (w/o earth terminal).

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Value
      J84-1 (CANH) - J84-2 (CANL) Engine switch off 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN RH JUNCTION CONNECTOR - GATEWAY ECU)

    OK

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN LH JUNCTION CONNECTOR - CAN RH JUNCTION CONNECTOR)

  7. CHECK FOR OPEN IN CAN BUS MAIN WIRE (ECM - CAN LH JUNCTION CONNECTOR)


    1. A015Z5SE06

      Turn the engine switch off.

    2. Disconnect the ECM connector (A6).

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

      Standard Resistance
      Tester Connection Switch Condition Specified Value
      A6-14 (CANH) - A6-13 (CANL) Engine switch off 108 to 132 Ω

    NG

    RECONNECT CONNECTOR Click here

    OK

    REPLACE ECM Click here

  8. RECONNECT CONNECTOR


    1. Reconnect the ECM connector (A6).


    NEXT

  9. CHECK FOR OPEN IN CAN BUS MAIN WIRE (GATEWAY ECU - CAN LH JUNCTION CONNECTOR)


    1. A015Z77E23

      Disconnect the gateway ECU connector (J76).

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

      Standard Resistance
      Tester Connection Switch Condition Specified Value
      J76-17 (CA1H) - J76-18 (CA1L) Engine switch off 108 to 132 Ω

    NG

    RECONNECT CONNECTOR Click here

    OK

    REPLACE GATEWAY ECU Click here

  10. RECONNECT CONNECTOR


    1. Reconnect the gateway ECU connector (J76).


    NEXT

  11. CHECK FOR OPEN IN CAN BUS MAIN WIRE (CAN RH JUNCTION CONNECTOR - GATEWAY ECU)


    1. A0161BKE23

      Disconnect the CAN main bus line connector (J84) from the CAN RH junction connector B side (w/o earth terminal).

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Value
      J84-1 (CANH) - J84-2 (CANL) Engine switch off 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN RH JUNCTION CONNECTOR - GATEWAY ECU)

    OK

  12. RECONNECT CONNECTOR


    1. Reconnect the CAN main bus line connector (J84) to the CAN RH junction connector B side (w/o earth terminal).


    NEXT

  13. CHECK FOR OPEN IN CAN BUS MAIN WIRE (ECM - CAN LH JUNCTION CONNECTOR)


    1. A016341E20

      Disconnect the CAN main bus line connector (J2) from the CAN LH junction connector A side (w/ earth terminal).

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

      Standard Resistance
      Tester Connection Switch Condition Specified Value
      J2-1 (CANH) - J2-2 (CANL) Engine switch off 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (ECM - CAN LH JUNCTION CONNECTOR)

    OK

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN LH JUNCTION CONNECTOR - CAN RH JUNCTION CONNECTOR)