CAN COMMUNICATION SYSTEM Open in Bus 4 Main Bus Line

DESCRIPTION

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

  • CAN main bus lines or connector

  • Central gateway ECU (network gateway ECU)

  • Airbag ECU assembly

  • No. 2 CAN junction connector

  • No. 5 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

B004QPOE11
*a Central Gateway ECU (Network Gateway ECU)
*b No. 5 CAN Junction Connector
*c No. 2 CAN Junction Connector
*d Airbag ECU Assembly

CAUTION / NOTICE / HINT

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

  • 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 at least approximately 20 seconds. Turn the blind spot monitor system on using the blind spot monitor main switch (ON/OFF switch), turn the cruise control main switch on and then drive the vehicle at a speed of 20 km/h (12 mph) or more for approximately 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.

    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 MAIN BUS LINES (NO. 5 CAN JUNCTION CONNECTOR)


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

    2. Disconnect the F73 No. 5 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
      F73-1 (CANH) - F73-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 2 CAN junction connector
      F73-2 (CANH) - F73-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Central gateway ECU (network gateway ECU)
      Result
      Result Proceed to
      OK A
      NG (Line to central gateway ECU (network gateway ECU)) B
      NG (Line to No. 2 CAN junction connector) C

    A

    REPLACE NO. 5 CAN JUNCTION CONNECTOR

    C

    CHECK FOR OPEN IN CAN MAIN BUS LINES (NO. 2 CAN JUNCTION CONNECTOR) Click here

    B

  2. CHECK FOR OPEN IN CAN MAIN BUS LINES (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) - NO. 5 CAN JUNCTION CONNECTOR)


    1. Reconnect the F73 No. 5 CAN junction connector.

    2. Disconnect the F59 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
      F59-22 (CA2H) - F59-7 (CA2L) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Result
      OK
      NG

    OK

    REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) Click here

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) - NO. 5 CAN JUNCTION CONNECTOR)

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


    1. Reconnect the F73 No. 5 CAN junction connector.

    2. Disconnect the F70 No. 2 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
      F70-7 (CANH) - F70-18 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 5 CAN junction connector
      F70-8 (CANH) - F70-19 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Airbag ECU assembly
      Result
      Result Proceed to
      OK A
      NG (Line to No. 5 CAN junction connector) B
      NG (Line to Airbag ECU assembly) C

    A

    REPLACE NO. 2 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 2 CAN JUNCTION CONNECTOR - NO. 5 CAN JUNCTION CONNECTOR)

    C

  4. CHECK FOR OPEN IN CAN MAIN BUS LINES (AIRBAG ECU ASSEMBLY - NO. 2 CAN JUNCTION CONNECTOR)


    1. Reconnect the F70 No. 2 CAN junction connector.

    2. Disconnect the F56 airbag ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F56-13 (CANH) - F56-22 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Result
      OK
      NG

    OK

    REPLACE AIRBAG ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (AIRBAG ECU ASSEMBLY - NO. 2 CAN JUNCTION CONNECTOR)