CAN COMMUNICATION SYSTEM Open in Bus Chassis Local Bus Line

DESCRIPTION

There may be an open circuit in the CAN main line and/or CAN branch line when the resistance between terminals 19 (CAYH) and 20 (CAYL) of the central gateway ECU (network gateway ECU) is 70 Ω or higher.

Symptom Trouble Area
The resistance between terminals 19 (CAYH) and 20 (CAYL) of the central gateway ECU (network gateway ECU) is 70 Ω or higher.

  • Open in CAN main bus wire

  • Central gateway ECU (network gateway ECU)

  • Skid control ECU assembly

  • No. 8 CAN junction connector

  • No. 17 CAN junction connector

  • No. 18 CAN junction connector

WIRING DIAGRAM


  1. for LHD

    B004AKWE07

  2. for RHD

    B004AKWE09

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 (SKID CONTROL ECU ASSEMBLY - NO. 8 CAN JUNCTION CONNECTOR)


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

    2. B004CDPC01
      *a

      Front view of wire harness connector

      (to Skid Control ECU Assembly)

      Disconnect the skid control ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A9-10 (CA2H) - A9-11 (CA2L) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Result
      OK
      NG

    OK

    REPLACE SKID CONTROL ECU ASSEMBLY for LHD: REPLACE SKID CONTROL ECU ASSEMBLY Click here
    REPLACE SKID CONTROL ECU ASSEMBLY for RHD: REPLACE SKID CONTROL ECU ASSEMBLY Click here

    NG

  2. CONNECT CONNECTOR


    1. Reconnect the A9 skid control ECU assembly connector.

      Result
      Proceed to
      NEXT

    NEXT

  3. CHECK VEHICLE TYPE


    1. Check vehicle type.

      Result
      Result Proceed to
      for LHD A
      for RHD B

    B

    CHECK FOR OPEN IN CAN BUS WIRE (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 18 CAN JUNCTION CONNECTOR) Click here

    A

  4. CHECK FOR OPEN IN CAN BUS WIRE (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 17 CAN JUNCTION CONNECTOR)


    1. B004BXLC19
      *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
      P59-19 (CAYH) - P59-20 (CAYL) 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

  5. CONNECT CONNECTOR


    1. Reconnect the P59 central gateway ECU (network gateway ECU) connector.

      Result
      Proceed to
      NEXT

    NEXT

  6. CHECK FOR OPEN IN CAN BUS WIRE (NO. 17 CAN JUNCTION CONNECTOR)


    1. B004CJAC25
      *a

      Front view of wire harness connector

      (to No. 17 CAN Junction Connector)
      *b to No. 18 CAN Junction Connector
      *c to Central Gateway ECU (Network Gateway ECU)

      Disconnect the No. 17 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
      X114-1 (CANH) - X114-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 18 CAN junction connector
      X114-3 (CANH) - X114-14 (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 (Central gateway ECU [network gateway ECU] CAN main wire) B
      NG (No. 18 CAN junction connector CAN main wire) C

    A

    REPLACE NO. 17 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 17 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU])

    C

  7. CONNECT CONNECTOR


    1. Reconnect the X114 No. 17 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  8. CHECK FOR OPEN IN CAN BUS WIRE (NO. 18 CAN JUNCTION CONNECTOR)


    1. B004CJAC26
      *a

      Front view of wire harness connector

      (to No. 18 CAN Junction Connector)
      *b to No. 17 CAN Junction Connector
      *c to No. 8 CAN Junction Connector

      Disconnect the No. 18 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
      b10-9 (CANH) - b10-20 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 17 CAN junction connector
      b10-11 (CANH) - b10-22 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 8 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (No. 17 CAN junction connector CAN main wire) B
      NG (No. 8 CAN junction connector CAN main wire) C

    A

    REPLACE NO. 18 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 18 CAN JUNCTION CONNECTOR - NO. 17 CAN JUNCTION CONNECTOR)

    C

  9. CONNECT CONNECTOR


    1. Reconnect the b10 No. 18 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  10. CHECK FOR OPEN IN CAN BUS WIRE (NO. 8 CAN JUNCTION CONNECTOR)

    Tech Tips


    • Before disconnecting the connectors, make a note of where it is connected.

    • Reconnect the connector to its original position.


    1. Disconnect the No. 8 CAN junction connectors.

      B004CABC06
      *1 No. 8 CAN Junction Connector - -
      *a

      Rear view of wire harness connector

      (to No. 8 CAN Junction Connector)

      		 - -
      Wiring Color
      Code Color (CANH Side) Color (CANL Side) Connect to
      P125 Y W Skid control ECU assembly
      P128 G W No. 18 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
      P125-1 (CANH) - P125-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Skid control ECU assembly
      P128-1 (CANH) - P128-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 18 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (No. 18 CAN junction connector CAN main wire) B
      NG (Skid control ECU assembly CAN main wire) C

    A

    REPLACE NO. 8 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - NO. 18 CAN JUNCTION CONNECTOR)

    C

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - SKID CONTROL ECU ASSEMBLY)

  11. CHECK FOR OPEN IN CAN BUS WIRE (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 18 CAN JUNCTION CONNECTOR)


    1. B004BXLC19
      *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
      P59-19 (CAYH) - P59-20 (CAYL) 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

  12. CONNECT CONNECTOR


    1. Reconnect the P59 central gateway ECU (network gateway ECU) connector.

      Result
      Proceed to
      NEXT

    NEXT

  13. CHECK FOR OPEN IN CAN BUS WIRE (NO. 18 CAN JUNCTION CONNECTOR)


    1. B004CJAC26
      *a

      Front view of wire harness connector

      (to No. 18 CAN Junction Connector)
      *b to No. 17 CAN Junction Connector
      *c to Central Gateway ECU (Network Gateway ECU)

      Disconnect the No. 18 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
      b10-9 (CANH) - b10-20 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 17 CAN junction connector
      b10-11 (CANH) - b10-22 (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 (Central gateway ECU [network gateway ECU] CAN main wire) B
      NG (No. 17 CAN junction connector CAN main wire) C

    A

    REPLACE NO. 18 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 18 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU])

    C

  14. CONNECT CONNECTOR


    1. Reconnect the b10 No. 18 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  15. CHECK FOR OPEN IN CAN BUS WIRE (NO. 17 CAN JUNCTION CONNECTOR)


    1. B004CJAC25
      *a

      Front view of wire harness connector

      (to No. 17 CAN Junction Connector)
      *b to No. 18 CAN Junction Connector
      *c to No. 8 CAN Junction Connector

      Disconnect the No. 17 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
      X114-1 (CANH) - X114-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 18 CAN junction connector
      X114-3 (CANH) - X114-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 8 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (No. 18 CAN junction connector CAN main wire) B
      NG (No. 8 CAN junction connector CAN main wire) C

    A

    REPLACE NO. 17 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 17 CAN JUNCTION CONNECTOR - NO. 18 CAN JUNCTION CONNECTOR)

    C

  16. CONNECT CONNECTOR


    1. Reconnect the X114 No. 17 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  17. CHECK FOR OPEN IN CAN BUS WIRE (NO. 8 CAN JUNCTION CONNECTOR)

    Tech Tips


    • Before disconnecting the connectors, make a note of where it is connected.

    • Reconnect the connector to its original position.


    1. Disconnect the No. 8 CAN junction connectors.

      B004CABC06
      *1 No. 8 CAN Junction Connector - -
      *a

      Rear view of wire harness connector

      (to No. 8 CAN Junction Connector)

      		 - -
      Wiring Color
      Code Color (CANH Side) Color (CANL Side) Connect to
      P125 Y W Skid control ECU assembly
      P128 G W No. 17 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
      P125-1 (CANH) - P125-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Skid control ECU assembly
      P128-1 (CANH) - P128-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 17 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (No. 17 CAN junction connector CAN main wire) B
      NG (Skid control ECU assembly CAN main wire) C

    A

    REPLACE NO. 8 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - NO. 17 CAN JUNCTION CONNECTOR)

    C

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - SKID CONTROL ECU ASSEMBLY)