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 sensor assembly

  • No. 2 CAN junction connector

  • No. 4 CAN junction connector

  • No. 3 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

B006Y2DE01

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 ignition 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 ignition 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.

    Click here

  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

    DTC check procedure: Turn the ignition switch to ON 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 MAIN BUS LINES (NO. 3 JUNCTION CONNECTOR)


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

    2. Disconnect the R99 No. 3 junction connector.

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

      B007124C16
      *a

      Front view of wire harness connector

      (to No. 3 Junction Connector)

      		 *b to Central Gateway ECU (Network Gateway ECU)
      *c to No. 2 CAN Junction Connector - -
      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      R99-10 (CANH) - R99-21 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Central gateway ECU (network gateway ECU)
      R99-11 (CANH) - R99-22 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 2 CAN junction connector
      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. 3 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. 3 JUNCTION CONNECTOR)


    1. Reconnect the R99 No. 3 junction connector.

    2. Disconnect the K76 central gateway ECU (network gateway ECU) connector.

    3. B006YY1C17
      *a

      Front view of wire harness connector

      (to Central Gateway ECU (Network Gateway ECU))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K76-22 (CA2H) - K76-7 (CA2L) Cable disconnected from negative (-) 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. 3 JUNCTION CONNECTOR)

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


    1. Reconnect the R99 No. 3 junction connector.

    2. Disconnect the A67 No. 2 CAN junction connector.

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

      B007124C17
      *a

      Front view of wire harness connector

      (to No. 2 CAN Junction Connector)

      		 *b to No. 3 Junction Connector
      *c to No. 4 CAN Junction Connector - -
      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      A67-2 (CANH) - A67-13 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 3 junction connector
      A67-5 (CANH) - A67-16 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 4 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (Line to No. 3 junction connector) B
      NG (Line to No. 4 CAN junction connector) C

    A

    REPLACE NO. 2 CAN JUNCTION CONNECTOR

    B

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

    C

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


    1. Reconnect the A67 No. 2 CAN junction connector.

    2. Disconnect the K127 No. 4 CAN junction connector.

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

      B007124C18
      *a

      Front view of wire harness connector

      (to No. 4 CAN Junction Connector)

      		 *b to No. 2 CAN Junction Connector
      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      K127-6 (CANH) - K127-17 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 2 CAN junction connector
      Result
      Result
      OK
      NG

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 4 CAN JUNCTION CONNECTOR - NO. 2 CAN JUNCTION CONNECTOR)

    OK

  5. CHECK FOR OPEN IN CAN MAIN BUS LINES (NO. 4 CAN JUNCTION CONNECTOR)


    1. Reconnect the K127 No. 4 CAN junction connector.

    2. Disconnect the K128 No. 4 CAN junction connector.

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

      B007124C19
      *a

      Front view of wire harness connector

      (to No. 4 CAN Junction Connector)

      		 *b to Airbag Sensor Assembly
      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      K128-6 (CANH) - K128-17 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Airbag sensor assembly
      Result
      Result
      OK
      NG

    OK

    REPLACE NO. 4 CAN JUNCTION CONNECTOR

    NG

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


    1. Reconnect the K128 No. 4 CAN junction connector.

    2. Disconnect the K73 airbag sensor assembly connector.

    3. B0070SIC03
      *a

      Front view of wire harness connector

      (to Airbag Sensor Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K73-26 (CANH) - K73-27 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Result
      OK
      NG

    OK

    REPLACE AIRBAG SENSOR ASSEMBLY Click here

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (AIRBAG SENSOR ASSEMBLY - NO. 4 CAN JUNCTION CONNECTOR)