CAN COMMUNICATION SYSTEM Check Bus 4 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 22 (CA2H) of the network gateway ECU and terminal 16 (BAT) of the DLC3, or terminal 7 (CA2L) of the network gateway ECU and terminal 16 (BAT) of the DLC3.

Symptom Trouble Area
No resistance exists between terminal 22 (CA2H) of the network gateway ECU and terminal 16 (BAT) of the DLC3, or terminal 7 (CA2L) of the network gateway ECU and terminal 16 (BAT) of the DLC3.

  • Short in CAN main bus line

  • Short in CAN branch line

  • Network gateway ECU

  • Skid control ECU (brake actuator assembly)

  • Occupant detection ECU (w/ 12.3 Inch Display Type Audio and Visual System)

  • 4WD ECU assembly (for AWD)

  • Tire pressure warning ECU and receiver

  • Absorber control ECU (w/ AVS)

  • Steering sensor

  • Yaw rate sensor assembly (w/ TFT Meter Type Combination Meter Assembly)

  • Power steering ECU assembly

  • Airbag sensor assembly

  • No. 1 CAN junction connector

  • No. 7 CAN junction connector

  • No. 8 CAN junction connector

  • No. 9 CAN junction connector

  • No. 12 CAN junction connector

WIRING DIAGRAM

B005ORZE03
B005PBKE03

CAUTION / NOTICE / HINT

Note


  • 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 or any 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 negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

    Click here

  • 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

  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

  • DTC check procedure: Drive the vehicle at a speed of 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.

    Click here

Tech Tips


  • Operating the engine switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.

  • 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 LINE (NETWORK GATEWAY ECU)


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

    2. Disconnect the J75 network gateway ECU connector.

      B005ON4C05
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to Network Gateway ECU)

      		 - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J75-22 (CA2H) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      J75-7 (CA2L) - J12-16 (BAT)
      Result
      Result
      OK
      NG

    OK

    REPLACE NETWORK GATEWAY ECU Click here

    NG

  2. CHECK FOR SHORT TO +B IN CAN BUS LINE (NO. 9 CAN JUNCTION CONNECTOR)


    1. Reconnect the J75 network gateway ECU connector.

    2. Disconnect the R41 No. 9 CAN junction connector.

      B005OSGC10
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 9 CAN Junction Connector)

      		 *b to No. 12 CAN Junction Connector
      *c

      to Tire Pressure Warning ECU and Receiver

      (for Tire Pressure Warning ECU and Receiver Integrated with Electrical Key Receiver / Tire Pressure Warning ECU and Receiver (Stand Alone) (Quarter Panel))

      		 *d to No. 8 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
      R41-9 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 12 CAN junction connector
      R41-20 (CANL) - J12-16 (BAT)
      R41-10 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Tire pressure warning ECU and receiver*
      R41-21 (CANL) - J12-16 (BAT)
      R41-11 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 8 CAN junction connector
      R41-22 (CANL) - J12-16 (BAT)
      *: for Tire Pressure Warning ECU and Receiver Integrated with Electrical Key Receiver / Tire Pressure Warning ECU and Receiver (Stand Alone) (Quarter Panel)
      Result
      Result Proceed to
      OK A
      NG (No. 8 CAN junction connector) B
      NG (ECU or sensor bus line) C
      NG (No. 12 CAN junction connector main line) D

    A

    REPLACE NO. 9 CAN JUNCTION CONNECTOR

    C

    GO TO STEP 7 Click here

    D

    CHECK FOR SHORT TO +B IN CAN BUS LINE (NO. 12 CAN JUNCTION CONNECTOR) Click here

    B

  3. CHECK FOR SHORT TO +B IN CAN BUS LINE (NO. 1 CAN JUNCTION CONNECTOR)


    1. Reconnect the R41 No. 9 CAN junction connector.

    2. Disconnect the A86 No. 1 CAN junction connector.

      B005OSGC11
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 1 CAN Junction Connector)

      		 *b to No. 8 CAN Junction Connector
      *c to Network Gateway ECU *d to Skid Control ECU (Brake Actuator Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      A86-8 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 8 CAN junction connector
      A86-19 (CANL) - J12-16 (BAT)
      A86-9 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Network gateway ECU
      A86-20 (CANL) - J12-16 (BAT)
      A86-10 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Skid control ECU (brake actuator assembly)
      A86-21 (CANL) - J12-16 (BAT)
      Result
      Result Proceed to
      OK A
      NG (Network gateway ECU main line) B
      NG (ECU or sensor bus line) C
      NG (No. 8 CAN junction connector main line) D

    A

    REPLACE NO. 1 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NETWORK GATEWAY ECU - NO. 1 CAN JUNCTION CONNECTOR)

    C

    GO TO STEP 7 Click here

    D

  4. CHECK FOR SHORT TO +B IN CAN BUS LINE (NO. 8 CAN JUNCTION CONNECTOR)


    1. Reconnect the A86 No. 1 CAN junction connector.

    2. Disconnect the R38 No. 8 CAN junction connector.

      B005OSGC12
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 8 CAN Junction Connector)

      		 *b to No. 9 CAN Junction Connector
      *c to No. 1 CAN Junction Connector *d

      to Occupant Detection ECU

      (w/ 12.3 Inch Display Type Audio and Visual System)
      *e

      to 4WD ECU Assembly

      (for AWD)

      		 - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      R38-1 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 9 CAN junction connector
      R38-12 (CANL) - J12-16 (BAT)
      R38-2 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 1 CAN junction connector
      R38-13 (CANL) - J12-16 (BAT)
      R38-3 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Occupant detection ECU*1
      R38-14 (CANL) - J12-16 (BAT)
      R38-4 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher 4WD ECU assembly*2
      R38-15 (CANL) - J12-16 (BAT)
      *1: w/ 12.3 Inch Display Type Audio and Visual System
      *2: for AWD
      Result
      Result Proceed to
      OK A
      NG (No. 1 CAN junction connector main line) B
      NG (ECU or sensor bus line) C
      NG (No. 9 CAN junction connector main line) D

    A

    REPLACE NO. 8 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 1 CAN JUNCTION CONNECTOR - NO. 8 CAN JUNCTION CONNECTOR)

    C

    GO TO STEP 7 Click here

    D

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - NO. 9 CAN JUNCTION CONNECTOR)

  5. CHECK FOR SHORT TO +B IN CAN BUS LINE (NO. 12 CAN JUNCTION CONNECTOR)


    1. Reconnect the R41 No. 9 CAN junction connector.

    2. Disconnect the S65 No. 12 CAN junction connector.

      B005OSGC14
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 12 CAN Junction Connector)

      		 *b to No. 7 CAN Junction Connector
      *c to No. 9 CAN Junction Connector *d

      to Tire Pressure Warning ECU and Receiver

      (for Tire Pressure Warning ECU and Receiver (Stand Alone) (Roof))
      *e

      to Absorber Control ECU

      (w/ AVS)

      		 - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      S65-8 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 7 CAN junction connector
      S65-19 (CANL) - J12-16 (BAT)
      S65-9 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 9 CAN junction connector
      S65-20 (CANL) - J12-16 (BAT)
      S65-10 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Tire pressure warning ECU and receiver*1
      S65-21 (CANL) - J12-16 (BAT)
      S65-11 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Absorber control ECU*2
      S65-22 (CANL) - J12-16 (BAT)
      *1: for Tire Pressure Warning ECU and Receiver (Stand Alone) (Roof)
      *2: w/ AVS
      Result
      Result Proceed to
      OK A
      NG (No. 9 CAN junction connector main line) B
      NG (ECU or sensor bus line) C
      NG (No. 7 CAN junction connector main line) D

    A

    REPLACE NO. 12 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 9 CAN JUNCTION CONNECTOR - NO. 12 CAN JUNCTION CONNECTOR)

    C

    GO TO STEP 7 Click here

    D

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


    1. Reconnect the S65 No. 12 CAN junction connector.

    2. Disconnect the J99 No. 7 CAN junction connector.

      B005OSGC15
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 7 CAN Junction Connector)

      		 *b to Airbag Sensor Assembly
      *c to Steering Sensor *d

      to Yaw Rate Sensor Assembly

      (w/ TFT Meter Type Combination Meter Assembly)
      *e to Power Steering ECU Assembly *f to No. 12 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
      J99-1 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Airbag sensor assembly
      J99-12 (CANL) - J12-16 (BAT)
      J99-2 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Steering sensor
      J99-13 (CANL) - J12-16 (BAT)
      J99-3 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Yaw rate sensor assembly*
      J99-14 (CANL) - J12-16 (BAT)
      J99-4 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Power steering ECU assembly
      J99-15 (CANL) - J12-16 (BAT)
      J99-6 (CANH) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 12 CAN junction connector
      J99-17 (CANL) - J12-16 (BAT)
      *: w/ TFT Meter Type Combination Meter Assembly
      Result
      Result Proceed to
      OK A
      NG (No. 12 CAN junction connector main line) B
      NG (ECU or sensor bus line) C

    A

    REPLACE NO. 7 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 7 CAN JUNCTION CONNECTOR - NO. 12 CAN JUNCTION CONNECTOR)

    C

  7. CHECK FOR SHORT TO +B IN CAN BUS LINE (ECU, SENSOR)


    1. Reconnect all wire harness connectors.

    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.

      Click here

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

      B005NNFC07
      *1 DLC3 - -
      *a

      Component with harness connected

      (Network Gateway ECU)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      J75-22 (CA2H) - J12-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      J75-7 (CA2L) - J12-16 (BAT)

      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.

      Result
      Result
      OK
      NG

    OK

    REPLACE CORRESPONDING ECU OR SENSOR

    NG

    REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR CAN BUS LINE OR CONNECTOR