CAN COMMUNICATION SYSTEM Open in Bus 1 Main Bus Line

DESCRIPTION

There may be an open circuit in one of the bus 1 main lines when the resistance between terminals 23 (CA1H) and 8 (CA1L) of the network gateway ECU is 70 Ω or higher.

Symptom Trouble Area
Resistance between terminals 23 (CA1H) and 8 (CA1L) of network gateway ECU is 70 Ω or higher.

  • CAN main bus line or connector

  • Network gateway ECU

  • No. 3 CAN junction connector

  • No. 10 CAN junction connector

This malfunction is not related to the lines of a bus 1 branch or to ECUs or sensors connected to a bus 1 branch.

WIRING DIAGRAM

B005PCKE07

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: Drive the vehicle at a speed of 36 km/h (22 mph) or more for 32 seconds or more, and with the dynamic radar cruise control system operated for 2 seconds 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.

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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 LINES (NO. 10 CAN JUNCTION CONNECTOR)


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

    2. Disconnect the S56 and S57 No. 10 CAN junction connectors.

      Tech Tips


      • Connectors that connect to the CAN junction connector can be distinguished by the color of their CAN bus lines.

      • Before disconnecting the connectors, make a note of where they are connected.

      • 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.

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

      B005NNUC01
      *a

      Rear view of wire harness connector

      (to No. 10 CAN Junction Connector)

      		 *b to Network Gateway ECU
      *c to No. 3 CAN Junction Connector - -
      Wiring Color:
      Code Color (CANH Side) Color (CANL Side) Connected to
      S56 G W Network gateway ECU
      S57 LG W No. 3 CAN junction connector
      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      S56-1 (CANH) - S56-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Network gateway ECU
      S57-1 (CANH) - S57-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 3 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (No. 3 CAN junction connector main line) B
      NG (Network gateway ECU main line) C

    A

    REPLACE NO. 10 CAN JUNCTION CONNECTOR

    C

    CHECK FOR OPEN IN CAN BUS MAIN LINES (NETWORK GATEWAY ECU - NO. 10 CAN JUNCTION CONNECTOR) Click here

    B

  2. CHECK FOR OPEN IN CAN BUS LINES (NO. 3 CAN JUNCTION CONNECTOR)


    1. Reconnect the S56 and S57 No. 10 CAN junction connectors.

    2. B005LZRC31
      *a

      Front view of wire harness connector

      (to No. 3 CAN Junction Connector)
      *b to Network Gateway ECU
      *c to No. 10 CAN Junction Connector

      Disconnect the J95 No. 3 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      J95-1 (CANH) - J95-11 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Network gateway ECU
      J95-10 (CANH) - J95-20 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 10 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (No. 10 CAN junction connector main line) B
      NG (Network gateway ECU main line) C

    A

    REPLACE NO. 3 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 3 CAN JUNCTION CONNECTOR - NO. 10 CAN JUNCTION CONNECTOR)

    C

  3. CHECK FOR OPEN IN CAN BUS MAIN LINES (NETWORK GATEWAY ECU - NO. 3 CAN JUNCTION CONNECTOR)


    1. Reconnect the J95 No. 3 CAN junction connector.

    2. B005NSTC56
      *a

      Front view of wire harness connector

      (to Network Gateway ECU)
      *b to No. 3 CAN Junction Connector
      *c to No. 10 CAN Junction Connector

      Disconnect the J75 network gateway ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J75-9 (CAXH) - J75-23 (CA1H) Cable disconnected from negative (-) battery terminal Below 1 Ω
      J75-8 (CA1L) - J75-24 (CAXL) Cable disconnected from negative (-) battery terminal Below 1 Ω
      Result
      Result
      OK
      NG

    OK

    REPLACE NETWORK GATEWAY ECU Click here

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NETWORK GATEWAY ECU - NO. 3 CAN JUNCTION CONNECTOR)

  4. CHECK FOR OPEN IN CAN BUS MAIN LINES (NETWORK GATEWAY ECU - NO. 10 CAN JUNCTION CONNECTOR)


    1. Reconnect the S56 and S57 No. 10 CAN junction connectors.

    2. B005NSTC56
      *a

      Front view of wire harness connector

      (to Network Gateway ECU)
      *b to No. 3 CAN Junction Connector
      *c to No. 10 CAN Junction Connector

      Disconnect the J75 network gateway ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J75-9 (CAXH) - J75-23 (CA1H) Cable disconnected from negative (-) battery terminal Below 1 Ω
      J75-8 (CA1L) - J75-24 (CAXL) Cable disconnected from negative (-) battery terminal Below 1 Ω
      Result
      Result
      OK
      NG

    OK

    REPLACE NETWORK GATEWAY ECU Click here

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NETWORK GATEWAY ECU - NO. 10 CAN JUNCTION CONNECTOR)