CAN COMMUNICATION SYSTEM(for LHD) Open in CAN Main Wire

DESCRIPTION

There may be an open circuit in the CAN main wire and/or DLC3 CAN branch wire when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is 70 Ω or higher.

Symptom Trouble Area
The resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is 70 Ω or higher.

  • CAN main wire or connector

  • No. 2 CAN junction connector

  • No. 3 CAN junction connector

  • ECM

  • Combination meter assembly

  • DLC3 CAN branch wire or connector

WIRING DIAGRAM

A00009HE01
*a No. 2 CAN Junction Connector
*b Combination Meter Assembly
*c No. 3 CAN Junction Connector

CAUTION / NOTICE / HINT

Note


  • 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

  • Before measuring the resistance of the CAN bus, turn the power 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 (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the auxiliary battery terminal notice before proceeding with work.

    Click here

  • When replacing the combination meter assembly, make sure to replace it with a new one.

Tech Tips


  • Operating the power switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • 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.

  • Connectors that connect to the CAN junction connector can be distinguished by the color of their CAN bus lines. When the connectors have been disconnected from the CAN junction connector, reconnecting the connectors to non-original positions on the CAN junction connector does not affect system performance. However, it is preferred to reconnect the connectors to their original positions to avoid negative effects on the wiring such as tension on the wiring harnesses, and to make future maintenance easier.

PROCEDURE


  1. CHECK FOR OPEN IN CAN BUS WIRE (DLC3 CAN BRANCH WIRE)


    1. B002IOGC05
      *a Front view of DLC3

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I7-6 (CANH) - I7-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

      Note

      When the measured value is 133 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

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DLC3 (CANH, CANL)

    OK

  2. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 2 CAN JUNCTION CONNECTOR)


    1. A0000HBC03
      *a

      Front view of wire harness connector

      (to No. 2 CAN Junction Connector)
      *b to No. 3 CAN Junction Connector
      *c to Combination Meter Assembly

      Disconnect the No. 2 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I93-5 (CANH) - I93-15 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      I93-7 (CANH) - I93-17 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (to No. 3 CAN junction connector CAN main wire) B
      NG (to combination meter assembly CAN main wire) C

    A

    REPLACE NO. 2 CAN JUNCTION CONNECTOR

    C

    CONNECT CONNECTOR Click here

    B

  3. CONNECT CONNECTOR


    1. Reconnect the No. 2 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  4. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 3 CAN JUNCTION CONNECTOR)


    1. A0000HBC04
      *a

      Front view of wire harness connector

      (to No. 3 CAN Junction Connector)
      *b to No. 2 CAN Junction Connector
      *c to ECM

      Disconnect the No. 3 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I94-6 (CANH) - I94-16 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      I94-7 (CANH) - I94-17 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (to ECM CAN main wire) B
      NG (to No. 2 CAN junction connector CAN main wire) C

    A

    REPLACE NO. 3 CAN JUNCTION CONNECTOR

    C

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 3 CAN JUNCTION CONNECTOR - NO. 2 CAN JUNCTION CONNECTOR)

    B

  5. CONNECT CONNECTOR


    1. Reconnect the No. 3 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  6. CHECK FOR OPEN IN CAN BUS WIRE (ECM - NO. 3 CAN JUNCTION CONNECTOR)


    1. A00004FC09
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A35-13 (CANH) - A35-26 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO ECM (ECM - NO. 3 CAN JUNCTION CONNECTOR)

  7. CONNECT CONNECTOR


    1. Reconnect the No. 2 CAN junction connectors.

      Result
      Proceed to
      NEXT

    NEXT

  8. CHECK FOR OPEN IN CAN BUS MAIN WIRE (COMBINATION METER ASSEMBLY - NO. 2 CAN JUNCTION CONNECTOR)


    1. A0001AJC07
      *a

      Front view of wire harness connector

      (to Combination Meter Assembly)

      Disconnect the combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I10-29 (CANH) - I10-30 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

    NG

    REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO COMBINATION METER ASSEMBLY (COMBINATION METER ASSEMBLY - NO. 2 CAN JUNCTION CONNECTOR)