CAN COMMUNICATION SYSTEM(for LHD with Central Gateway ECU) Open in Bus 2 Main Bus Line

DESCRIPTION

There may be an open circuit in one of the bus 2 CAN main wires 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 central gateway ECU (network gateway ECU) is 70 Ω or higher.
  • CAN main wire or connector

  • CAN branch wire or connector

  • ECM

  • Combination meter assembly

  • Central gateway ECU (network gateway ECU)

  • No. 1 CAN junction connector

  • No. 2 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

B00272SE01
*a No. 2 CAN Junction Connector
*b Central Gateway ECU (Network Gateway ECU)
*c No. 1 CAN Junction Connector
*d Combination Meter 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 ignition switch off and leave the vehicle for 1 minute or more without operating the key, 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 battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work.

    Click here

  • After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed.

    Click here

Tech Tips


  • Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • 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 WIRE (NO. 2 CAN JUNCTION CONNECTOR)


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

      B0024L4C52
      *a

      Front view of wire harness connector

      (to No. 2 CAN Junction Connector)

      *b to ECM
      *c to No. 1 CAN Junction Connector - -
    2. Disconnect the 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
      G68-5 (CANH) - G68-15 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      G68-6 (CANH) - G68-16 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (No. 1 CAN junction connector CAN main wire) B
      NG (ECM CAN main wire) C

    A
    C
    B
  2. CONNECT CONNECTOR


    1. Reconnect the G68 No. 2 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT
  3. CHECK FOR OPEN IN CAN BUS WIRE (NO. 1 CAN JUNCTION CONNECTOR)


    1. Disconnect the No. 1 CAN junction connector.

      B0024L4C53
      *a

      Front view of wire harness connector

      (to No. 1 CAN Junction Connector)

      *b to Combination Meter Assembly
      *c to No. 2 CAN Junction Connector *d to Central Gateway ECU (Network Gateway ECU)
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      G67-5 (CANH) - G67-15 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      G67-6 (CANH) - G67-16 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      G67-9 (CANH) - G67-19 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      Result
      Result Proceed to
      OK A
      NG (No. 2 CAN junction connector CAN main wire) B
      NG (Combination meter assembly CAN main wire) C
      NG (Central gateway ECU [network gateway ECU] CAN branch wire) D

    A
    B
    D
    C
  4. CONNECT CONNECTOR


    1. Reconnect the G67 No. 1 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT
  5. CHECK FOR OPEN IN CAN BUS WIRE (COMBINATION METER ASSEMBLY)


    1. B0027LHC15
      *a

      Rear view of wire harness connector

      (to Combination Meter Assembly)

      Disconnect the combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G9-36 (CANH) - G9-35 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK
    NG
  6. CONNECT CONNECTOR


    1. Reconnect the G67 No. 1 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT
  7. CHECK FOR OPEN IN CAN BUS WIRE (CENTRAL GATEWAY ECU)


    1. B002547C72
      *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
      G128-18 (CA4H) - G128-17 (CA4L) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Result
      Proceed to
      OK
      NG

    OK
    NG
  8. CONNECT CONNECTOR


    1. Reconnect the G68 No. 2 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT
  9. CHECK FOR OPEN IN CAN BUS WIRE (ECM)


    1. B0024UTC10
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G85-17 (CANH) - G85-28 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK
    NG