CAN COMMUNICATION SYSTEM Open in Bus 1 Main Bus Line

DESCRIPTION

There may be an open circuit in one of the CAN main bus lines 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 the central gateway ECU (network gateway ECU) is 70 Ω or higher.

  • CAN main bus wire or connector

  • CAN branch wire or connector

  • Central gateway ECU (network gateway ECU)

  • No. 3 CAN junction terminal

  • No. 9 CAN junction terminal

  • No. 6 CAN junction connector

  • No. 7 CAN junction connector

  • No. 16 CAN junction connector

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

WIRING DIAGRAM


  1. for LHD

    B004W0AE03

  2. for RHD

    B004TMAE01

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 power 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 (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary 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 power 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

Tech Tips


  • Before disconnecting related connectors for inspection, push in on each connector body to check that the connector is not loose or disconnected.

  • When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.

PROCEDURE


  1. CHECK FOR OPEN IN CAN BUS WIRE (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU])


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

    2. Disconnect the G66 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
      G66-18 (CA4H) - G66-17 (CA4L) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    B

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 7 CAN JUNCTION CONNECTOR)

    C

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 6 CAN JUNCTION CONNECTOR)

    A

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


    1. Reconnect the G66 central gateway ECU (network gateway ECU) connector.

    2. Disconnect the G125 No. 6 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
      G125-7 (CANH) - G125-1 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 16 CAN junction connector
      G125-10 (CANH) - G125-4 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 7 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (No. 16 CAN junction connector CAN main wire) B
      NG (No. 7 CAN junction connector CAN main wire) C

    A

    REPLACE NO. 6 CAN JUNCTION CONNECTOR

    C

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

    B

  3. CHECK FOR OPEN IN CAN BUS WIRE (NO. 16 CAN JUNCTION CONNECTOR)


    1. Reconnect the G125 No. 6 CAN junction connector.

    2. Disconnect the L123 No. 16 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
      L123-1 (CANH) - L123-11 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 6 CAN junction connector
      L123-2 (CANH) - L123-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 3 CAN junction terminal
      Result
      Result Proceed to
      OK A
      NG (No. 3 CAN junction terminal CAN main wire) B
      NG (No. 6 CAN junction connector CAN main wire) C

    A

    REPLACE NO. 16 CAN JUNCTION CONNECTOR

    C

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 16 CAN JUNCTION CONNECTOR - NO. 6 CAN JUNCTION CONNECTOR)

    B

  4. CHECK FOR OPEN IN CAN BUS WIRE (NO. 3 CAN JUNCTION TERMINAL - NO. 16 CAN JUNCTION CONNECTOR)


    1. Reconnect the L123 No. 16 CAN junction connector.

    2. Disconnect the L126 No. 3 CAN junction terminal connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L126-3 (CANH) - L126-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NO. 3 CAN JUNCTION TERMINAL

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 3 CAN JUNCTION TERMINAL - NO. 16 CAN JUNCTION CONNECTOR)

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


    1. Reconnect the G125 No. 6 CAN junction connector.

    2. Disconnect the G126 No. 7 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
      G126-2 (CANH) - G126-8 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 9 CAN junction terminal
      G126-12 (CANH) - G126-6 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 6 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (No. 9 CAN junction terminal CAN main wire) B
      NG (No. 6 CAN junction connector CAN main wire) C

    A

    REPLACE NO. 7 CAN JUNCTION CONNECTOR

    C

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 7 CAN JUNCTION CONNECTOR - NO. 6 CAN JUNCTION CONNECTOR)

    B

  6. CHECK FOR OPEN IN CAN BUS WIRE (NO. 9 CAN JUNCTION TERMINAL - NO. 7 CAN JUNCTION CONNECTOR)


    1. Reconnect the G126 No. 7 CAN junction connector.

    2. Disconnect the G127 No. 9 CAN junction terminal connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G127-3 (CANH) - G127-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NO. 9 CAN JUNCTION TERMINAL

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 9 CAN JUNCTION TERMINAL - NO. 7 CAN JUNCTION CONNECTOR)