CAN COMMUNICATION SYSTEM(for LHD) Open in Bus 2 Main Bus Line

DESCRIPTION

There may be an open circuit in one of the bus 2 main lines and/or central gateway ECU (network gateway ECU) CAN 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.

  • Bus 2 CAN main wire or connector

  • Bus 2 CAN branch wire or connector

  • ECM

  • Combination meter assembly

  • Central gateway ECU (network gateway ECU)

  • No. 2 CAN junction connector

  • No. 3 CAN junction connector

  • No. 9 CAN junction connector

This malfunction is not related to the lines of a bus 2 branch except the central gateway ECU (network gateway ECU) CAN branch wire or to ECUs or sensors connected a bus 2 branch.

WIRING DIAGRAM

B002EE1E07

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. 9 CAN JUNCTION CONNECTOR)


    1. B002C76C01
      *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
      A13-13 (CANH) - A13-14 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

  2. CONNECT CONNECTOR


    1. Reconnect the A13 ECM connector.

      Result
      Proceed to
      NEXT

    NEXT

  3. CHECK FOR OPEN IN CAN BUS WIRE (COMBINATION METER ASSEMBLY - NO. 3 CAN JUNCTION CONNECTOR)


    1. B002EHDC09
      *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
      K33-29 (CANH) - K33-30 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

    NG

  4. CONNECT CONNECTOR


    1. Reconnect the K33 combination meter assembly connector.

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK FOR OPEN IN CAN BUS WIRE (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) - NO. 3 CAN JUNCTION CONNECTOR)


    1. B002CUFC30
      *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
      K66-18 (CA4H) - K66-17 (CA4L) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) Click here

    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. 9 CAN JUNCTION CONNECTOR)


    1. Disconnect the No. 9 CAN junction connectors.

      B002E8YC01
      *1 No. 9 CAN Junction Connector - -
      *a

      Rear view of wire harness connector

      (to No. 9 CAN Junction Connector)

      		 - -
      Code Color (CANH Side) Color (CANL Side) Connect to
      U49 R W ECM
      U50 G W 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
      U49-1 (CANH) - U49-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω ECM
      U50-1 (CANH) - U50-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 2 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (ECM CAN main wire) B
      NG (No. 2 CAN junction connector CAN main wire) C

    A

    REPLACE NO. 9 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 9 CAN JUNCTION CONNECTOR - ECM)

    C

  8. CONNECT CONNECTOR


    1. Reconnect the U49 and U50 No. 9 CAN junction connectors.

      Result
      Proceed to
      NEXT

    NEXT

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


    1. Disconnect the No. 2 CAN junction connectors.

      B002DRPC32
      *1 No. 2 CAN Junction Connector - -
      *a

      Rear view of wire harness connector

      (to No. 2 CAN Junction Connector)

      		 - -
      Code Color (CANH Side) Color (CANL Side) Connect to
      K82 B W No. 3 CAN Junction Connector
      k84 G W No. 9 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
      K82-1 (CANH) - K82-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 3 CAN junction connector
      K84-1 (CANH) - K84-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 9 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (No. 9 CAN junction connector CAN main wire) B
      NG (No. 3 CAN junction connector CAN 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. 9 CAN JUNCTION CONNECTOR)

    C

  10. CONNECT CONNECTOR


    1. Reconnect the K82 and K84 No. 2 CAN junction connectors.

      Result
      Proceed to
      NEXT

    NEXT

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


    1. Disconnect the No. 3 CAN junction connectors.

      B002DRPC33
      *1 No. 3 CAN Junction Connector - -
      *a

      Rear view of wire harness connector

      (to No. 3 CAN Junction Connector)

      		 - -
      Code Color (CANH Side) Color (CANL Side) Connect to
      K90 B W No. 2 CAN Junction Connector
      K92 G W Central Gateway ECU (Network Gateway ECU)
      K97 BE W Combination Meter Assembly

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      K90-1 (CANH) - K90-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 2 CAN junction connector
      K92-1 (CANH) - K92-2 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω Central gateway ECU (network gateway ECU)
      K97-1 (CANH) - K97-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Combination meter assembly
      Result
      Result Proceed to
      OK A
      NG (Central gateway ECU (network gateway ECU) CAN branch wire) B
      NG (No. 2 CAN junction connector CAN main wire) C
      NG (Combination meter assembly CAN main wire) D

    A

    REPLACE NO. 3 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (NO. 3 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))

    C

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

    D

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 3 CAN JUNCTION CONNECTOR - COMBINATION METER ASSEMBLY)