CAN COMMUNICATION SYSTEM Check Bus 4 Lines for Short Circuit

DESCRIPTION

There may be a short circuit between the bus 4 main lines and/or bus 4 branch lines when the resistance between terminals 22 (CA2H) and 7 (CA2L) of the network gateway ECU is below 54 Ω.

Symptom Trouble Area
Resistance between terminals 22 (CA2H) and 7 (CA2L) of network gateway ECU is below 54 Ω.

  • 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

B005ORZE02
B005PBKE01

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.

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  • 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.

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  • 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.

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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 IN CAN BUS LINES (NETWORK GATEWAY ECU)


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

    2. B005NSTC63
      *a

      Front view of wire harness connector

      (to Network Gateway ECU)

      Disconnect the J75 network gateway ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J75-22 (CA2H) - J75-7 (CA2L) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Result
      OK
      NG

    OK

    REPLACE NETWORK GATEWAY ECU Click here

    NG

  2. CHECK FOR SHORT IN CAN BUS LINES (AIRBAG SENSOR ASSEMBLY)


    1. Reconnect the J75 network gateway ECU connector.

    2. B005P8TC24
      *a

      Front view of wire harness connector

      (to Airbag Sensor Assembly)

      Disconnect the J20 airbag sensor assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J20-13 (CANH) - J20-22 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Result
      OK
      NG

    OK

    REPLACE AIRBAG SENSOR ASSEMBLY Click here

    NG

  3. CHECK FOR SHORT IN CAN BUS LINES (NO. 9 CAN JUNCTION CONNECTOR)


    1. Reconnect the J20 airbag sensor assembly connector.

    2. B005O44C56
      *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 Quarter)
      *d to No. 8 CAN Junction Connector

      Disconnect the R41 No. 9 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) - R41-20 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 12 CAN junction connector
      R41-10 (CANH) - R41-21 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Tire pressure warning ECU and receiver*
      R41-11 (CANH) - R41-22 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 8 CAN junction connector
      *: for Quarter
      Result
      Result Proceed to
      OK A
      NG (No. 8 CAN junction connector) B
      NG (ECU or sensor branch line) C
      NG (No. 12 CAN junction connector main line) D

    A

    REPLACE NO. 9 CAN JUNCTION CONNECTOR

    C

    GO TO STEP 8 Click here

    D

    CHECK FOR SHORT IN CAN BUS LINES (NO. 12 CAN JUNCTION CONNECTOR) Click here

    B

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


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

    2. B005NYZC54
      *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)

      Disconnect the A86 No. 1 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
      A86-8 (CANH) - A86-19 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 8 CAN junction connector
      A86-9 (CANH) - A86-20 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Network gateway ECU
      A86-10 (CANH) - A86-21 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Skid control ECU (brake actuator assembly)
      Result
      Result Proceed to
      OK A
      NG (Network gateway ECU main line) B
      NG (ECU or sensor branch 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 8 Click here

    D

  5. CHECK FOR SHORT IN CAN BUS LINES (NO. 8 CAN JUNCTION CONNECTOR)


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

    2. B005O44C57
      *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)

      Disconnect the R38 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
      R38-1 (CANH) - R38-12 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 9 CAN junction connector
      R38-2 (CANH) - R38-13 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 1 CAN junction connector
      R38-3 (CANH) - R38-14 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Occupant detection ECU*1
      R38-4 (CANH) - R38-15 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher 4WD ECU assembly*2
      *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 branch 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 8 Click here

    D

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

  6. CHECK FOR SHORT IN CAN BUS LINES (NO. 12 CAN JUNCTION CONNECTOR)


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

    2. B005O44C58
      *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 Roof)
      *e

      to Absorber Control ECU

      (w/ AVS)

      Disconnect the S65 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
      S65-8 (CANH) - S65-19 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 7 CAN junction connector
      S65-9 (CANH) - S65-20 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 9 CAN junction connector
      S65-10 (CANH) - S65-21 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Tire pressure warning ECU and receiver*1
      S65-11 (CANH) - S65-22 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Absorber control ECU*2
      *1: for Roof
      *2: w/ AVS
      Result
      Result Proceed to
      OK A
      NG (No. 9 CAN junction connector main line) B
      NG (ECU or sensor branch 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 8 Click here

    D

  7. CHECK FOR SHORT IN CAN BUS LINES (NO. 7 CAN JUNCTION CONNECTOR)


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

    2. B005NYZC55
      *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

      Disconnect the J99 No. 7 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) - J99-12 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Airbag sensor assembly
      J99-2 (CANH) - J99-13 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Steering sensor
      J99-3 (CANH) - J99-14 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Yaw rate sensor assembly*
      J99-4 (CANH) - J99-15 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Power steering ECU assembly
      J99-6 (CANH) - J99-17 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 12 CAN junction connector
      *: 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 branch line) C
      NG (Airbag sensor assembly main line) D

    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)

    D

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (AIRBAG SENSOR ASSEMBLY - NO. 7 CAN JUNCTION CONNECTOR)

    C

  8. CHECK FOR SHORT IN CAN BUS LINES (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 short circuited branch line is connected.

      Click here

    3. B005MPFC25
      *a

      Component with harness connected

      (Network Gateway ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J75-22 (CA2H) - J75-7 (CA2L) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

      Tech Tips

      If the resistance becomes normal (between 54 and 69 Ω) 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 BRANCH LINES OR CONNECTOR