CAN COMMUNICATION SYSTEM Open in CAN Main Bus Line

DESCRIPTION

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

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

  • DLC3 branch wire or connector

  • CAN bus main wire or connector

  • Combination meter assembly

  • ECM

  • CAN No. 1 junction connector

  • CAN No. 2 junction connector

WIRING DIAGRAM

A01ELN3E03

INSPECTION PROCEDURE

Note


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

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

  • After the ignition 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 ignition 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 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 WIRE (DLC3 BRANCH WIRE)


    1. Turn the ignition switch off.

    2. A01EJIYE83
      Text in Illustration
      *1 DLC3

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      D1-6 (CANH) - D1-14 (CANL) Ignition switch off 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 wire. 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 WIRE CONNECTED TO DLC3

    OK

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


    1. A01EMIIE21
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector (A49).

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A49-13 (CANH) - A49-5 (CANL) Ignition switch off 108 to 132 Ω

    NG

    CHECK FOR OPEN IN CAN BUS WIRE (COMBINATION METER ASSEMBLY) Click here

    OK

    REPLACE ECM Click here

  3. CHECK FOR OPEN IN CAN BUS WIRE (COMBINATION METER ASSEMBLY)


    1. Reconnect the ECM connector.

    2. A01EMBVE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Combination Meter Assembly)

      Disconnect the combination meter assembly connector (E1).

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      E1-1 (CANH) - E1-9 (CANL) Ignition switch off 108 to 132 Ω

    NG

    CHECK FOR OPEN IN CAN BUS WIRE (CAN NO. 1 JUNCTION CONNECTOR - ECM) Click here

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

  4. CHECK FOR OPEN IN CAN BUS WIRE (CAN NO. 1 JUNCTION CONNECTOR - ECM)


    1. Reconnect the combination meter assembly connector.

    2. A01EKZ3E33
      Text in Illustration
      *1

      Front view of wire harness connector

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

      Disconnect the CAN No. 1 junction connector (A44).

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A44-4 (CANH) - A44-15 (CANL) Ignition switch off 108 to 132 Ω

    NG

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

    OK

  5. CHECK FOR OPEN IN CAN BUS WIRE (CAN NO. 1 JUNCTION CONNECTOR - CAN NO. 2 JUNCTION CONNECTOR)


    1. Reconnect the CAN No. 1 junction connector (A44).

    2. A01EKZ3E32
      Text in Illustration
      *1

      Front view of wire harness connector

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

      Disconnect the CAN No. 1 junction connector (D56).

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      D56-9 (CANH) - D56-20 (CANL) Ignition switch off 108 to 132 Ω

    NG

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

    OK

    REPLACE CAN NO. 1 JUNCTION CONNECTOR

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


    1. Reconnect the CAN No. 1 junction connector (D56).

    2. A01EKZ3E34
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *2 to Combination Meter Assembly
      *3 to CAN No. 1 Junction Connector

      Disconnect the CAN No. 2 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition Connect to
      D68-8 (CANH) - D68-19 (CANL) Ignition switch off 108 to 132 Ω Combination meter assembly
      D68-9 (CANH) - D68-20 (CANL) Ignition switch off 108 to 132 Ω CAN No. 1 junction connector
      Result
      Result Proceed to
      OK A
      NG (to Combination meter assembly main wire) B
      NG (to CAN No. 1 junction connector) C

    B

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 JUNCTION CONNECTOR - COMBINATION METER ASSEMBLY)

    C

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 JUNCTION CONNECTOR - CAN NO. 2 JUNCTION CONNECTOR)

    A

    REPLACE CAN NO. 2 JUNCTION CONNECTOR