CAN COMMUNICATION SYSTEM Open in Bus 5 Main Bus Line

DESCRIPTION

There may be an open circuit in one of the CAN main bus lines when the resistance between terminals 15 (CA5H) and 16 (CA5L) of the central gateway ECU (network gateway ECU) is 70 Ω or higher.

Symptom Trouble Area
Resistance between terminals 15 (CA5H) and 16 (CA5L) of central gateway ECU (network gateway ECU) is 70 Ω or higher.

  • CAN main bus line or connector

  • Central gateway ECU (network gateway ECU)

  • Hybrid vehicle control ECU

  • No. 4 CAN junction connector

  • No. 8 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

B002HMDE01
*a Hybrid Vehicle Control ECU
*b No. 8 CAN Junction Connector
*c No. 4 CAN Junction Connector
*d Central Gateway ECU (Network Gateway ECU)

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


  • Operating the power 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. 4 CAN JUNCTION CONNECTOR)


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

    2. B002KYWC03
      *a

      Front view of wire harness connector

      (to No. 4 CAN Junction Connector)
      *b to Central Gateway ECU (Network Gateway ECU)
      *c to No. 8 CAN Junction Connector

      Disconnect the No. 4 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
      I95-3 (CANH) - I95-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Central gateway ECU (network gateway ECU)
      I95-9 (CANH) - I95-19 (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. 8 CAN junction connector CAN main wire) B
      NG (Central gateway ECU [network gateway ECU] CAN main wire) C

    A

    REPLACE NO. 4 CAN JUNCTION CONNECTOR

    C

    CONNECT CONNECTOR Click here

    B

  2. CONNECT CONNECTOR


    1. Reconnect the I95 No. 4 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

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


    1. B002KYWC04
      *a

      Front view of wire harness connector

      (to No. 8 CAN Junction Connector)
      *b to Hybrid Vehicle Control ECU
      *c to No. 4 CAN Junction Connector

      Disconnect the No. 8 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
      I95-3 (CANH) - I95-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Hybrid vehicle control ECU
      I95-9 (CANH) - I95-19 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 4 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (Hybrid vehicle control ECU CAN main wire) B
      NG (No. 4 CAN junction connector CAN main wire) C

    A

    REPLACE NO. 8 CAN JUNCTION CONNECTOR

    C

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - NO. 4 CAN JUNCTION CONNECTOR)

    B

  4. CONNECT CONNECTOR


    1. Reconnect the Q32 No. 8 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK FOR OPEN IN CAN BUS WIRE (HYBRID VEHICLE CONTROL ECU - NO. 8 CAN JUNCTION CONNECTOR)


    1. B002IGDC10
      *a

      Front view of wire harness connector

      (to Hybrid Vehicle Control ECU)

      Disconnect the hybrid vehicle control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I115-34(CA2H) - I115-35(CA2L) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE HYBRID VEHICLE CONTROL ECU Click here

    NG

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

  6. CONNECT CONNECTOR


    1. Reconnect the I95 No. 4 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

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


    1. B002JICC57
      *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
      I164-15(CA5H) - I164-16(CA5L) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 4 CAN JUNCTION CONNECTOR)

    NG

    REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) for LHD: Click here
    REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) for RHD: Click here