CAN COMMUNICATION SYSTEM(for RHD) Open in Bus 4 Main Bus Line

DESCRIPTION

There may be an open circuit in one of the bus 4 main lines and/or central gateway ECU (network gateway ECU) CAN branch wire when the resistance between terminals 22 (CA2H) and 7 (CA2L) of the central gateway ECU (network gateway ECU) is 70 Ω or higher.

Symptom Trouble Area
Resistance between terminals 22 (CA2H) and 7 (CA2L) of central gateway ECU (network gateway ECU) is 70 Ω or higher.
  • Bus 4 CAN main wire or connector

  • Bus 4 CAN branch wire or connector

  • ECM

  • Central gateway ECU (network gateway ECU)

  • No. 2 CAN junction terminal

  • No. 6 CAN junction connector

  • No. 8 CAN junction connector

  • No. 10 CAN junction connector

This malfunction is not related to the lines of a bus 4 branch except the central gateway ECU (network gateway ECU) CAN branch wire or to ECUs or sensors connected a bus 4 branch.

WIRING DIAGRAM

B002E7FE03

CAUTION / NOTICE / HINT

Note


  • 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.

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  • 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.

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  • 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), wait at least 60 seconds, and then drive the vehicle at a speed of 40 km/h (25 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.

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  • Before replacing the ECM, refer to Service Bulletin.

Tech Tips


  • Operating the engine 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 (ECM - NO. 8 CAN JUNCTION CONNECTOR)


    1. B002C76C03
      *a

      Front view of wire harness connector

      (to ECM)

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

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A13-11 (CANP) - A13-12 (CANN) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK
    NG
  2. CONNECT CONNECTOR


    1. Reconnect the A13 ECM connector.

      Result
      Proceed to
      NEXT

    NEXT
  3. CHECK FOR OPEN IN CAN BUS WIRE (NO. 2 CAN JUNCTION TERMINAL - NO. 10 CAN JUNCTION CONNECTOR)


    1. B002ET0C69
      *a

      Front view of wire harness connector

      (to No. 2 CAN Junction Terminal)

      Disconnect the No. 2 CAN junction terminal connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      U57-3 (CANH) - U57-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK
    NG
  4. CONNECT CONNECTOR


    1. Reconnect the U57 No. 2 CAN junction terminal connector.

      Result
      Proceed to
      NEXT

    NEXT
  5. CHECK FOR OPEN IN CAN BUS WIRE (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) - NO. 6 CAN JUNCTION CONNECTOR)


    1. B002CUFC49
      *a

      Front view of wire harness connector

      (to Central Gateway ECU (Network Gateway ECU))

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K66-22 (CA2H) - K66-7 (CA2L) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Result
      Proceed to
      OK
      NG

    OK
    NG
  6. CONNECT CONNECTOR


    1. Reconnect the K66 central gateway ECU (network gateway ECU) connector.

      Result
      Proceed to
      NEXT

    NEXT
  7. CHECK FOR OPEN IN CAN BUS WIRE (NO. 8 CAN JUNCTION CONNECTOR)


    1. B002DQNC67
      *a

      Front view of wire harness connector

      (to No. 8 CAN Junction Connector)

      *b to ECM
      *c to No. 6 CAN Junction Connector

      Disconnect the No. 8 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
      K110-1 (CANH) - K110-12 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω ECM
      K110-5 (CANH) - K110-16 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 6 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (ECM CAN main wire) B
      NG (No. 6 CAN junction connector CAN main wire) C

    A
    B
    C
  8. CONNECT CONNECTOR


    1. Reconnect the K110 No. 8 CAN junction connector.

      Result
      Proceed to
      NEXT

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


    1. B002DQNC68
      *a

      Front view of wire harness connector

      (to No. 6 CAN Junction Connector)

      *b to No. 10 CAN Junction Connector
      *c to Central Gateway ECU (Network Gateway ECU)
      *d to No. 8 CAN Junction Connector

      Disconnect the No. 6 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
      K108-2 (CANH) - K108-13 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 10 CAN Junction Connector
      K108-4 (CANH) - K108-15 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω Central gateway ECU (network gateway ECU)
      K108-5 (CANH) - K108-16 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 7 CAN Junction Connector
      Result
      Result Proceed to
      OK A
      NG (Central gateway ECU (network gateway ECU) CAN branch wire) B
      NG (No. 8 CAN junction connector CAN main wire) C
      NG (No. 10 CAN junction connector CAN main wire) D

    A
    B
    C
    D
  10. CONNECT CONNECTOR


    1. Reconnect the K108 No. 6 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT
  11. CHECK FOR OPEN IN CAN BUS WIRE (NO. 10 CAN JUNCTION CONNECTOR)


    1. B002DQNC42
      *a

      Front view of wire harness connector

      (to No. 10 CAN Junction Connector)

      *b to No. 2 CAN Junction Terminal
      *c to No. 6 CAN Junction Connector

      Disconnect the No. 10 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
      U55-5 (CANH) - U55-16 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 2 CAN junction terminal
      U55-6 (CANH) - U55-17 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 6 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (No. 6 CAN junction connector CAN main wire) B
      NG (No. 2 CAN junction terminal CAN main wire) C

    A
    B
    C