CAN COMMUNICATION SYSTEM (for RHD) Open in CAN Main Wire

DESCRIPTION

There may be an open circuit one of the V Bus main lines and/or a DLC3 branch line when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is 70 Ω or higher.

Symptom Trouble Area
Resistance between terminals 6 (CANH) and 14 (CANL) of DLC3 is 70 Ω or higher.

  • DLC3 branch line or connector

  • CAN main bus line or connector

  • ECM

  • Power management control ECU

  • No. 1 CAN Junction Connector

  • No. 2 CAN Junction Connector

  • No. 3 CAN Junction Connector

This malfunction is not related to the lines of a CAN main bus branch or to ECUs or sensors connected a CAN main bus branch.

WIRING DIAGRAM

A01FVHME02

INSPECTION PROCEDURE

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, 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 auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the auxiliary battery terminal notice 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: Allow the radar cruise control system (vehicle control mode) to operate for 1 second or more.

  • 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 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.

  • Connectors that connect to the CAN junction connector can be distinguished by color of their CAN bus lines. When the connectors have been disconnected from the CAN junction connector, reconnecting the connectors to non-original positions on the CAN junction connector does not affect system performance. However, it is preferred to reconnect the connectors to their original positions to avoid negative effects on the wiring such as tension on the wiring harnesses, and to make future maintenance easier.

PROCEDURE


  1. CHECK FOR OPEN IN CAN BUS LINES (DLC3 BRANCH LINE)


    1. A01FSTYE01
      Text in Illustration
      *a Front view of DLC3

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

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

      Standard Resistance
      Tester Connection Connection Specified Condition
      N20-6 (CANH) - N20-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

      Note

      When the measured value is 133 Ω or higher and a CAN communication system DTC is output, there may be a fault besides disconnection of the DLC3 branch line. For that reason, troubleshooting should be performed again from How to Proceed with Troubleshooting after repairing the trouble area Click here.


    NG

    REPAIR OR REPLACE CAN BRANCH LINE CONNECTED TO DLC3

    OK

  2. CHECK FOR OPEN IN CAN BUS LINES (ECM - NO. 1 CAN JUNCTION CONNECTOR)


    1. A01FRO7E03
      Text in Illustration
      *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 Connection Specified Condition
      A20-13 (CANH) - A20-26 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    NG

    CHECK FOR OPEN IN CAN BUS LINES (POWER MANAGEMENT CONTROL ECU - NO. 3 CAN JUNCTION CONNECTOR) Click here

    OK

    REPLACE ECM Click here

  3. CHECK FOR OPEN IN CAN BUS LINES (POWER MANAGEMENT CONTROL ECU - NO. 3 CAN JUNCTION CONNECTOR)


    1. A01FTF2E03
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Reconnect the ECM connector.

    2. Disconnect the power management control ECU connector.

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

      Standard Resistance
      Tester Connection Connection Specified Condition
      N92-25 (CA1H) - N95-24 (CA1L) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    NG

    CHECK FOR OPEN IN CAN BUS LINES (NO. 1 CAN JUNCTION CONNECTOR) Click here

    OK

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

  4. CHECK FOR OPEN IN CAN BUS LINES (NO. 1 CAN JUNCTION CONNECTOR)


    1. Reconnect the power management control ECU connector.

      A01FTEJE01
      Text in Illustration
      *1 No. 1 CAN Junction Connector - -
      *a

      Rear view of wire harness connector

      (to No. 1 CAN Junction Connector)

      		 - -
      Wiring Color
      Code Color (CANH Side) Color (CANL Side) Connect to
      U50 P W No. 2 CAN Junction Connector
      U51 G W ECM

    2. Disconnect the wire harness connector from the No. 1 CAN junction connectors.

      Note


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

      • Reconnect the connector to its original position.

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

      Standard Resistance
      Tester Connection Connection Specified Condition Connected to
      U50-1 (CANH) - U50-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 2 CAN Junction Connector
      U51-1 (CANH) - U51-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω ECM
      Result
      Result Proceed to
      OK A
      NG (ECM main line) B
      NG (No. 2 CAN junction connector main line) C

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 1 CAN JUNCTION CONNECTOR - ECM)

    C

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

    A

    REPLACE NO. 1 CAN JUNCTION CONNECTOR

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


    1. Reconnect the wire harness connector from the No. 1 CAN junction connectors.

      A01FUGME01
      Text in Illustration
      *1 No. 2 CAN Junction Connector - -
      *a

      Rear view of wire harness connector

      (to No. 2 CAN Junction Connector)

      		 - -
      Wiring Color
      Code Color (CANH Side) Color (CANL Side) Connect to
      N107 B W No. 3 CAN Junction Connector
      N113 P W No. 1 CAN Junction Connector

    2. Disconnect the wire harness connector from the No. 2 CAN junction connectors.

      Note


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

      • Reconnect the connector to its original position.

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

      Standard Resistance
      Tester Connection Connection Specified Condition Connected to
      N107-1 (CANH) - N107-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 3 CAN Junction Connector
      N113-1 (CANH) - N113-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 1 CAN Junction Connector
      Result
      Result Proceed to
      OK A
      NG (No. 1 CAN junction connector main line) B
      NG (No. 3 CAN junction connector main line) C

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 2 CAN JUNCTION CONNECTOR - NO. 1 CAN JUNCTION CONNECTOR)

    C

    CHECK FOR OPEN IN CAN BUS LINES (NO. 3 CAN JUNCTION CONNECTOR) Click here

    A

    REPLACE NO. 2 CAN JUNCTION CONNECTOR

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


    1. Reconnect the wire harness connector from the No. 2 CAN junction connectors.

      A01FUGME11
      Text in Illustration
      *1 No. 3 CAN Junction Connector - -
      *a

      Rear view of wire harness connector

      (to No. 3 CAN Junction Connector)

      		 - -
      Wiring Color
      Code Color (CANH Side) Color (CANL Side) Connect to
      N120 P W Power Management Control ECU
      N121 B W No. 2 CAN Junction Connector

    2. Disconnect the wire harness connector from the No. 3 CAN junction connectors.

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

      Standard Resistance
      Tester Connection Connection Specified Condition Connected to
      N120-1 (CANH) - N120-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Power Management Control ECU
      N121-1 (CANH) - N121-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 2 CAN Junction Connector
      Result
      Result Proceed to
      OK A
      NG (No. 2 CAN junction connector main line) B
      NG (Power management control ECU main line) C

    B

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

    C

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 3 CAN JUNCTION CONNECTOR - POWER MANAGEMENT CONTROL ECU)

    A

    REPLACE NO. 3 CAN JUNCTION CONNECTOR