CAN COMMUNICATION SYSTEM(for LHD) Check Bus 3 Line for Short to +B

DESCRIPTION

There may be a short circuit between one of the CAN bus lines and +B when no resistance exists between terminal 6 (CA3H) of the central gateway ECU and terminal 16 (BAT) of the DLC3, or terminal 21 (CA3L) of the central gateway ECU and terminal 16 (BAT) of the DLC3.

Detection Item Trouble Area
No resistance exists between terminal 6 (CA3H) of the central gateway ECU and terminal 16 (BAT) of the DLC3, or terminal 21 (CA3L) of the central gateway ECU and terminal 16 (BAT) of the DLC3.

  • Short to +B in bus 3 CAN main wires

  • Short to +B in bus 3 CAN branch wires

  • Central gateway ECU

  • Multi-media module receiver assembly

  • Bus buffer ECU*1

  • DCM (telematics transceiver)*2

  • No. 5 CAN junction connector

  • No. 6 CAN junction connector

  • No. 2 CAN junction terminal

WIRING DIAGRAM

B001A4PE10

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 engine 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 engine 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 as normal Click here.

  • DTC check procedure: Turn the engine 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.

Tech Tips


  • Operating the engine 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 SHORT TO B+ IN CAN BUS WIRE (CENTRAL GATEWAY ECU - NO. 5 CAN JUNCTION CONNECTOR)


    1. B0018VOE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Central Gateway ECU)
      *b Front view of DLC3

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

    2. Disconnect the central gateway ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E137-6 (CA3H) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      E137-21 (CA3L) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

    OK

    REPLACE CENTRAL GATEWAY ECU Click here

    NG

  2. CONNECT CONNECTOR


    1. Reconnect the E137 central gateway ECU connector.


    NEXT

  3. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 2 CAN JUNCTION TERMINAL - NO. 6 CAN JUNCTION CONNECTOR)


    1. B001A6RE01
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to No. 2 CAN Junction Terminal)
      *b Front view of DLC3

      Disconnect the No. 2 CAN junction terminal connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F114-3 (CANH) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      F114-2 (CANL) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

    OK

    REPLACE NO. 2 CAN JUNCTION TERMINAL

    NG

  4. CONNECT CONNECTOR


    1. Reconnect the F114 No. 2 CAN junction terminal connector.


    NEXT

  5. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 5 CAN JUNCTION CONNECTOR)


    1. Disconnect the No. 5 CAN junction connector.

      B001A9SE01
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to No. 5 CAN Junction Connector)

      		 *b Front view of DLC3
      *c to Central Gateway ECU *d to Bus Buffer ECU (w/ Bus Buffer ECU)
      *e to Multi-media Module Receiver Assembly *f to No. 6 CAN Junction Connector

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connect to
      E163-8 (CANH) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Central gateway ECU
      E163-19 (CANL) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      E163-9 (CANH) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Bus buffer ECU*
      E163-20 (CANL) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      E163-10 (CANH) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Multi-media module receiver assembly
      E163-21 (CANL) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      E163-11 (CANH) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 6 CAN junction connector
      E163-22 (CANL) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      • *: w/ Bus Buffer ECU

      Result
      Result Proceed to
      OK A
      NG (Central gateway ECU CAN main wire) B
      NG (No. 6 CAN junction connector CAN main wire) C
      NG (ECU or sensor CAN branch wires) D

    A

    REPLACE NO. 5 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 5 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU)

    D

    CHECK FOR SHORT TO B+ IN CAN BUS WIRE (ECU, SENSOR) Click here

    C

  6. CONNECT CONNECTOR


    1. Reconnect the E163 No. 5 CAN junction connector.


    NEXT

  7. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 6 CAN JUNCTION CONNECTOR)


    1. Disconnect the No. 6 CAN junction connector.

      B0019T4E01
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to No. 6 CAN Junction Connector)

      		 *b Front view of DLC3
      *c to DCM (Telematics Transceiver) (w/ Emergency Call Switch) *d to No. 5 CAN Junction Connector
      *e to No. 2 CAN Junction Terminal - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connect to
      F98-5 (CANH) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher DCM (telematics transceiver)*
      F98-16 (CANL) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      F98-6 (CANH) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 5 CAN junction connector
      F98-17 (CANL) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      F98-7 (CANH) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 2 CAN junction terminal
      F98-18 (CANL) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      • *: w/ Emergency Call Switch

      Result
      Result Proceed to
      OK A
      NG (No. 5 CAN junction connector CAN main wire) B
      NG (No. 2 CAN junction terminal CAN main wire) C
      NG (ECU or sensor CAN branch wires) D

    A

    REPLACE NO. 6 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 6 CAN JUNCTION CONNECTOR - NO. 5 CAN JUNCTION CONNECTOR)

    C

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 6 CAN JUNCTION CONNECTOR - NO. 2 CAN JUNCTION TERMINAL)

    D

  8. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (ECU, SENSOR)


    1. B0018JCE01
      Text in Illustration
      *a

      Component with harness connected

      (Central Gateway ECU)
      *b Front view of DLC3

      Reconnect the CAN junction connector.

    2. Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the bus line shorted to +B is connected

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E137-6 (CA3H) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      E137-21 (CA3L) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Tech Tips

      If the resistance changes to 6 kΩ or higher when the connector is disconnected from the ECU or sensor, there may be a short in the ECU or sensor.


    OK

    REPLACE CORRESPONDING ECU OR SENSOR

    NG

    REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR CAN BRANCH WIRES OR CONNECTOR