CAN COMMUNICATION SYSTEM Open in Bus 2 Main Bus Line

DESCRIPTION

There may be an open circuit in one of the CAN main bus wire and/or a central gateway ECU (network gateway ECU) branch wire when the resistance between terminals 18 (CA4H) and 17 (CA4L) of the central gateway ECU (network gateway ECU) is 70 Ω or higher.

Symptom Trouble Area
Resistance between terminals 18 (CA4H) and 17 (CA4L) of central gateway ECU (network gateway ECU) is 70 Ω or higher.

  • CAN main bus wire or connector

  • Central gateway ECU (network gateway ECU) branch wire

  • ECM

  • Combination meter assembly

  • No. 1 CAN junction connector

  • No. 2 CAN junction connector

This malfunction is not related to the lines of a CAN branch except the central gateway ECU (network gateway ECU) branch wire or to ECUs or sensors connected to a CAN branch.

WIRING DIAGRAM

B00596IE04
*a Combination Meter Assembly
*b Central Gateway ECU (Network Gateway ECU)
*c No. 1 CAN Junction Connector
*d No. 2 CAN Junction Connector

CAUTION / NOTICE / HINT

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

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 engine switch off and leave the vehicle for 1 minute or more without operating the key or any 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 engine 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

  • Some parts must be initialized and set when replacing or removing and installing parts.

    Click here

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

    DTC check procedure: Turn the engine switch on (IG) and wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.

  • After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed as normal.

    Click here

  • When replacing the combination meter assembly, always replace it with a new one. If a combination meter assembly which was installed to another vehicle is used, the information stored in it will not match the information from the vehicle and a DTC may be stored

Tech Tips


  • Operating the engine 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.

PROCEDURE


  1. CHECK FOR OPEN IN CAN BUS WIRE (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 1 CAN JUNCTION CONNECTOR)


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

    2. B005A96C56
      *a

      Front view of wire harness connector

      (to Central Gateway ECU [Network Gateway ECU])

      Disconnect the central gateway ECU (network gateway ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I164-18 (CA4H) - I164-17 (CA4L) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 1 CAN JUNCTION CONNECTOR)

    OK

  2. CONNECT CONNECTOR


    1. Connect the I164 central gateway ECU (network gateway ECU) connector.

      Result
      Proceed to
      Next

    Next

  3. CHECK FOR OPEN IN CAN BUS WIRE (NO. 1 CAN JUNCTION CONNECTOR)


    1. B005A8EC11
      *a

      Front view of wire harness connector

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

      Disconnect the No. 1 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      I93-5 (CANH) - I93-15 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 2 CAN junction connector
      I93-7 (CANH) - I93-17 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Combination meter assembly
      Result
      Result Proceed to
      OK A
      NG (Combination meter assembly CAN main wire) B
      NG (No. 2 Can junction connector main wire) C

    A

    REPLACE NO. 1 CAN JUNCTION CONNECTOR

    C

    CONNECT CONNECTOR Click here

    B

  4. CONNECT CONNECTOR


    1. Connect the I93 No. 1 CAN junction connector.

      Result
      Proceed to
      Next

    Next

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


    1. B00598JC01
      *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 (-) 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 OR CONNECTOR (COMBINATION METER ASSEMBLY - NO. 1 CAN JUNCTION CONNECTOR)

  6. CONNECT CONNECTOR


    1. Connect the I93 No. 1 CAN junction connector.

      Result
      Proceed to
      Next

    Next

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


    1. B005A8EC08
      *a

      Front view of wire harness connector

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

      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 Connected to
      I94-6 (CANH) - I94-16 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 1 CAN junction connector
      I94-7 (CANH) - I94-17 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω ECM
      Result
      Result Proceed to
      OK A
      NG (ECM CAN main wire) B
      NG (No. 1 Can junction connector main wire) C

    A

    REPLACE NO. 2 CAN JUNCTION CONNECTOR

    B

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

    C

  8. CONNECT CONNECTOR


    1. Connect the I94 No. 2 CAN junction connector.

      Result
      Proceed to
      Next

    Next

  9. CHECK FOR OPEN IN CAN BUS WIRE (ECM - NO. 2 CAN JUNCTION CONNECTOR)


    1. B0057GIC01
      *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 (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM for 8AR-FTS: Click here
    REPLACE ECM for 3ZR-FAE: Click here

    NG

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