CAN COMMUNICATION SYSTEM Check CAN Bus Lines for Short Circuit (LHD Models)

DESCRIPTION

There may be a short circuit in the CAN bus main wire and/or CAN branch wire when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is below 54 Ω.

Symptom Trouble Area
Resistance between terminals 6 (CANH) and 14 (CANL) of DLC3 is below 54 Ω.

  • Short in CAN bus main wire

  • Short in CAN bus branch wire

  • ECM

  • Certification ECU (Smart key ECU)

  • Combination meter

  • Power steering ECU

  • Center airbag sensor assembly

  • Skid control ECU

  • Steering angle sensor

  • Yaw rate sensor

  • Main body ECU (Multiplex network body ECU)

  • Power management control ECU

  • Navigation ECU (Display and navigation module display)

  • CAN No. 1 junction connector

  • CAN No. 2 junction connector

WIRING DIAGRAM

A01NFJFE01
A01NHXDE02

INSPECTION PROCEDURE

Note


  • Turn the power switch off before measuring the resistances between CAN bus main wires and between CAN bus branch wires.

  • Turn the power switch off before inspecting CAN bus wires for a ground short.

  • After the power switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.

  • Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the power switch, any other switches or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.

Tech Tips


  • Operating the power 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 WIRE (CAN NO. 1 J/C - CAN NO. 2 J/C)


    1. Turn the power switch off.

    2. A01NDFUE62
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No.1 Junction Connector)
      *2 to CAN No. 2 Junction Connector

      Disconnect the CAN No. 1 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F70-7 (CANH) - F70-18 (CANL) Power switch off 108 to 132 Ω

    NG

    CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 2 J/C - CAN NO. 1 J/C) Click here

    OK

  2. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 1 J/C - POWER MANAGEMENT CONTROL ECU)


    1. A01NDFUE92
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *2 to Power Management Control ECU

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F70-9 (CANH) - F70-20 (CANL) Power switch off 108 to 132 Ω

    NG

    CHECK FOR SHORT IN CAN BUS WIRES (POWER MANAGEMENT CONTROL ECU) Click here

    OK

  3. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 1 J/C - DLC3)


    1. A01NDFUE64
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *2 to DLC3

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F70-3 (CANH) - F70-14 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DLC3

    OK

  4. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 1 J/C - COMBINATION METER)


    1. A01NCNXE03

      Disconnect the combination meter connector.

    2. A01NDFUE65
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Combination Meter)
      *2

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *3 to Combination Meter

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F70-4 (CANH) - F70-15 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 1 J/C - COMBINATION METER)

    OK

  5. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 1 J/C - STEERING ANGLE SENSOR)


    1. A01NH8SE27

      Disconnect the steering angle sensor connector.

    2. A01NDFUE66
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Steering Angle Sensor)
      *2

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *3 to Steering Angle Sensor

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F70-2 (CANH) - F70-13 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 1 J/C - STEERING ANGLE SENSOR)

    OK

  6. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 1 J/C - POWER STEERING ECU)


    1. A01NGLNE15

      Disconnect the power steering ECU connector.

    2. A01NDFUE69
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Power Steering ECU)
      *2

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *3 to Power Steering ECU

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F70-1 (CANH) - F70-12 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 1 J/C - POWER STEERING ECU)

    OK

  7. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 1 J/C - YAW RATE SENSOR)


    1. A01NE4PE11

      Disconnect the yaw rate sensor connector.

    2. A01NDFUE68
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Yaw Rate Sensor)
      *2

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *3 to Yaw Rate Sensor

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F70-11 (CANH) - F70-22 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 1 J/C - YAW RATE SENSOR)

    OK

  8. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 1 J/C - CENTER AIRBAG SENSOR ASSEMBLY)


    1. A01NGT9E11

      Disconnect the center airbag sensor assembly connector.

    2. A01NDFUE70
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Center Airbag Sensor Assembly)
      *2

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *3 to Center Airbag Sensor Assembly

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F70-10 (CANH) - F70-21 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 1 J/C - CENTER AIRBAG SENSOR ASSEMBLY)

    OK

  9. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 1 J/C - MAIN BODY ECU)


    1. A01NH84E01

      Disconnect the main body ECU connector.

    2. A01NDFUE71
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Main Body ECU)
      *2

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *3 to Main Body ECU

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F70-5 (CANH) - F70-16 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 1 J/C - MAIN BODY ECU)

    OK

    CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 1 J/C)

  10. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 1 J/C)


    1. Reconnect the CAN No. 1 junction connector.

    2. A01NCRFE01
      Text in Illustration
      *1 DLC3

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F17-6 (CANH) - F17-14 (CANL) Power switch off 54 to 69 Ω

      Note

      The resistance must be measured after the main wire connected ECUs (ECM and power management control ECU), and the CAN No. 1 and No. 2 junction connectors are reconnected.


    NG

    REPLACE CAN NO. 1 JUNCTION CONNECTOR

    OK

  11. CHECK FOR SHORT IN CAN BUS WIRES (COMBINATION METER)


    1. Reconnect the combination meter connector.

    2. A01NCRFE01
      Text in Illustration
      *1 DLC3

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F17-6 (CANH) - F17-14 (CANL) Power switch off 54 to 69 Ω

    NG

    REPLACE COMBINATION METER Click here

    OK

  12. CHECK FOR SHORT IN CAN BUS WIRES (STEERING ANGLE SENSOR)


    1. Reconnect the steering angle sensor connector.

    2. A01NCRFE01
      Text in Illustration
      *1 DLC3

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F17-6 (CANH) - F17-14 (CANL) Power switch off 54 to 69 Ω

    NG

    REPLACE SPIRAL CABLE WITH STEERING ANGLE SENSOR Click here

    OK

  13. CHECK FOR SHORT IN CAN BUS WIRE (POWER STEERING ECU)


    1. Reconnect the power steering ECU connector.

    2. A01NCRFE01
      Text in Illustration
      *1 DLC3

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F17-6 (CANH) - F17-14 (CANL) Power switch off 54 to 69 Ω

    NG

    REPLACE POWER STEERING ECU Click here

    OK

  14. CHECK FOR SHORT IN CAN BUS WIRES (YAW RATE SENSOR)


    1. Reconnect the yaw rate sensor connector.

    2. A01NCRFE01
      Text in Illustration
      *1 DLC3

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F17-6 (CANH) - F17-14 (CANL) Power switch off 54 to 69 Ω

    NG

    REPLACE YAW RATE AND ACCELERATION SENSOR Click here

    OK

  15. CHECK FOR SHORT IN CAN BUS WIRES (CENTER AIRBAG SENSOR ASSEMBLY)


    1. Reconnect the center airbag sensor assembly connector.

    2. A01NCRFE01
      Text in Illustration
      *1 DLC3

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F17-6 (CANH) - F17-14 (CANL) Power switch off 54 to 69 Ω

    NG

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

  16. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 2 J/C - CAN NO. 1 J/C)


    1. Reconnect the CAN No. 1 junction connector.

    2. A01NDFUE74
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *2 to CAN No. 1 Junction Connector

      Disconnect the CAN No. 2 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F71-7 (CANH) - F71-18 (CANL) Power switch off 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 1 J/C - CAN NO. 2 J/C)

    OK

  17. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 2 J/C - ECM)


    1. A01NFYLE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *2 to ECM

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F71-9 (CANH) - F71-20 (CANL) Power switch off 108 to 132 Ω

    NG

    CHECK FOR SHORT IN CAN BUS WIRE (ECM) Click here

    OK

  18. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 2 J/C - CERTIFICATION ECU)


    1. A01NEQEE07

      Disconnect the certification ECU connector.

    2. A01NDFUE95
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Certification ECU)
      *2

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *3 to Certification ECU

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F71-2 (CANH) - F71-13 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 2 J/C - CERTIFICATION ECU)

    OK

  19. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 2 J/C - SKID CONTROL ECU)


    1. A01NDJ4E09
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)

      Disconnect the skid control ECU connector.

    2. A01NDFUE73
      Text in Illustration
      *2

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *3 to Skid Control ECU

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F71-1 (CANH) - F71-12 (CANL) Power switch off 1 MΩ or higher
      Result
      Result Proceed to
      OK (w/ Navigation system) A
      OK (w/o Navigation system) B
      NG C

    B

    CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 2 J/C) Click here

    C

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 2 J/C - SKID CONTROL ECU)

    A

  20. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 2 J/C - NAVIGATION ECU)

    Tech Tips

    For vehicles without the navigation system, go to the next step.


    1. A01NDYVE02

      Disconnect the navigation ECU connector.

    2. A01NDFUE75
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Navigation ECU)
      *2

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *3 to Navigation ECU

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F71-8 (CANH) - F71-19 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 2 J/C - NAVIGATION ECU)

    OK

  21. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 2 J/C)


    1. Reconnect the CAN No. 1 and No. 2 junction connectors.

    2. A01NCRFE01
      Text in Illustration
      *1 DLC3

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

      Note

      The resistance must be measured after the main wire connected ECUs (ECM and power management control ECU), and the CAN No. 1 and No. 2 junction connectors are reconnected.

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F17-6 (CANH) - F17-14 (CANL) Power switch off 54 to 69 Ω

    NG

    REPLACE CAN NO. 2 JUNCTION CONNECTOR

    OK

  22. CHECK FOR SHORT IN CAN BUS WIRES (CERTIFICATION ECU)


    1. Reconnect the certification ECU.

    2. A01NCRFE01
      Text in Illustration
      *1 DLC3

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F17-6 (CANH) - F17-14 (CANL) Power switch off 54 to 69 Ω
      Result
      Result Proceed to
      OK (w/ Navigation system) A
      OK (w/o Navigation system) B
      NG C

    B

    REPLACE SKID CONTROL ECU Click here

    C

    REPLACE CERTIFICATION ECU (SMART KEY ECU)

    A

  23. CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU)


    1. Reconnect the skid control ECU connector.

    2. A01NCRFE01
      Text in Illustration
      *1 DLC3

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F17-6 (CANH) - F17-14 (CANL) Power switch off 54 to 69 Ω
      Result
      Result Proceed to
      OK (for DVD) A
      OK (for HDD) B
      NG C

    B

    REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY (for HDD) Click here

    C

    REPLACE SKID CONTROL ECU Click here

    A

    REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY (for DVD) Click here

  24. CHECK FOR SHORT IN CAN BUS WIRE (ECM)


    1. A01NEJ1E07

      Disconnect the ECM connector.

    2. A01NDFUE96

      Disconnect the CAN No. 2 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F71-9 (CANH) - F71-20 (CANL) Power switch off 1 MΩ or higher
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECM)
      *2

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *3 to ECM

    NG

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 2 J/C - ECM)

    OK

    REPLACE ECM Click here

  25. CHECK FOR SHORT IN CAN BUS WIRES (POWER MANAGEMENT CONTROL ECU)


    1. A01NGZSE01
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Disconnect the power management control ECU connector.

    2. A01NDFUE94
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *2 to Power Management Control ECU

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F70-9 (CANH) - F70-20 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 J/C - POWER MANAGEMENT CONTROL ECU)

    OK

    REPLACE POWER MANAGEMENT CONTROL ECU Click here