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

DESCRIPTION

There may be a short circuit between the V1 bus main lines and/or CAN branch lines 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 main bus line

  • Short in CAN branch line

  • Power management control ECU

  • ECM

  • Main body ECU (Multiplex network body ECU)

  • Combination meter assembly

  • Skid control ECU (Brake booster with master cylinder assembly)

  • Steering angle sensor (Spiral cable with sensor sub-assembly)

  • Yaw rate and acceleration sensor

  • Power steering ECU assembly

  • Airbag sensor assembly

  • Transmission control ECU assembly

  • Certification ECU (Smart key ECU assembly)

  • Navigation ECU (Display and navigation module display)*1

  • Navigation ECU (Navigation computer sub-assembly)*2

  • CAN No. 1 junction connector

  • CAN No. 2 junction connector

  • CAN No. 3 junction connector

*1: w/ Navigation system (for DVD)

*2: w/ Navigation system (for HDD)

WIRING DIAGRAM

A003XKSE02
A003V9LE01

INSPECTION PROCEDURE

Note


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

  • Turn the power switch off before inspecting CAN bus lines 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 LINES (ECM)


    1. Turn the power switch off.

    2. A003XUOE05
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A60-13 (CANH) - A60-5 (CANL) Power switch off 108 to 132 Ω

    NG

    CHECK FOR SHORT IN CAN BUS LINES (COMBINATION METER ASSEMBLY) Click here

    OK

    REPLACE ECM Click here

  2. CHECK FOR SHORT IN CAN BUS LINES (COMBINATION METER ASSEMBLY)


    1. Reconnect the ECM connector.

    2. A003XCVE76
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Combination Meter Assembly)

      Disconnect the combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H19-32 (CANH) - H19-31 (CANL) Power switch off 108 to 132 Ω

    NG

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

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

  3. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 2 J/C)


    1. Reconnect the combination meter assembly connector.

    2. A003WY8E65
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *b to CAN No. 1 Junction Connector
      *c to CAN No. 3 Junction Connector
      *d to DLC3

      Disconnect the wire harness connector from the CAN No. 2 junction connector rear side.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition Connected to
      H104-1 (CANH) - H104-2 (CANL) Power switch off 108 to 132 Ω CAN No. 1 junction connector
      H104-4 (CANH) - H104-5 (CANL) Power switch off 108 to 132 Ω CAN No. 3 junction connector
      H104-7 (CANH) - H104-8 (CANL) Power switch off 1 MΩ or higher DLC3
      Result
      Result Proceed to
      OK A
      NG (CAN No. 1 J/C main line) B
      NG (CAN No. 3 J/C main line) C
      NG (DLC3 branch line) D

    B

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

    C

    CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 3 J/C - CAN NO. 2 J/C) Click here

    D

    REPAIR OR REPLACE CAN BRANCH LINE CONNECTED TO DLC3

    A

  4. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 2 J/C - POWER STEERING ECU ASSEMBLY)


    1. Disconnect the power steering ECU assembly connector.

    2. A003WY8E66
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *b to Power Steering ECU Assembly

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H104-10 (CANH) - H104-11 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (CAN NO. 2 J/C - POWER STEERING ECU ASSEMBLY)

    OK

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

    Tech Tips

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


    1. Disconnect the navigation ECU connector.

    2. A003WY8E67
      Text in Illustration
      *a

      Front view of wire harness connector

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

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H104-13 (CANH) - H104-14 (CANL) Power switch off 1 MΩ or higher

    NG

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

    OK

  6. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 2 J/C - YAW RATE AND ACCELERATION SENSOR)


    1. Disconnect the CAN No. 2 junction connector front side.

    2. Disconnect the yaw rate and acceleration sensor connector.

    3. A003WY8E68
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *b to Yaw Rate and Acceleration Sensor

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H105-12 (CANH) - H105-11 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (CAN NO. 2 J/C - YAW RATE AND ACCELERATION SENSOR)

    OK

  7. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 2 J/C - STEERING ANGLE SENSOR)


    1. Disconnect the steering angle sensor connector.

    2. A003WY8E69
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *b to Steering Angle Sensor

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H105-3 (CANH) - H105-2 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (CAN NO. 2 J/C - STEERING ANGLE SENSOR)

    OK

  8. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 2 J/C - AIRBAG SENSOR ASSEMBLY)


    1. Disconnect the airbag sensor assembly connector.

    2. A003WY8E70
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *b to Airbag Sensor Assembly

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H105-9 (CANH) - H105-8 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (CAN NO. 2 J/C - AIRBAG SENSOR ASSEMBLY)

    OK

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


    1. Disconnect the certification ECU (smart key ECU assembly) connector.

    2. A003WY8E71
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *b to Certification ECU (Smart Key ECU Assembly)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H105-6 (CANH) - H105-5 (CANL) Power switch off 1 MΩ or higher

    NG

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

    OK

  10. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 2 J/C)


    1. Reconnect the wire harness connector to the CAN No. 2 junction connector front side and rear side.

    2. A003YN4E27
      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
      H44-6 (CANH) - H44-14 (CANL) Power switch off 54 to 69 Ω

      Note


      • The resistance must be measured after the main line connected ECUs (ECM and combination meter assembly), CAN No. 1 junction connector, CAN No. 2 junction connector and CAN No. 3 junction connector are reconnected.

      • The resistance must be measured after the CAN No. 2 junction connector branch line connected ECU and sensor connectors are disconnected.


    NG

    REPLACE CAN NO. 2 JUNCTION CONNECTOR

    OK

  11. CHECK FOR SHORT IN CONNECTED COMPONENT (ECU, SENSOR)


    1. A003YN4E27
      Text in Illustration
      *1 DLC3

      Connect the probes of an ohmmeter to terminals 6 (CANH) and 14 (CANL) of the DLC3.

    2. While observing the resistance value shown on the ohmmeter, reconnect each ECU and sensor connector until the resistance becomes abnormal (Below 54 Ω).

      Tech Tips

      If the resistance becomes abnormal when an ECU connector is reconnected, there may be a short in the ECU.


    NEXT

    REPLACE CORRESPONDING ECU OR SENSOR

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


    1. Reconnect the wire harness connector to the CAN No. 2 junction connector rear side.

    2. A003VCVE29
      Text in Illustration
      *a

      Front view of wire harness connector

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

      Disconnect the instrument panel wire from 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
      H141-6 (CANH) - H141-12 (CANL) Power switch off 108 to 132 Ω

    NG

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

    OK

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


    1. Disconnect the main body ECU (multiplex network body ECU) connector.

    2. A003VCVE30
      Text in Illustration
      *a

      Front view of wire harness connector

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

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H141-5 (CANH) - H141-11 (CANL) Power switch off 1 MΩ or higher

    NG

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

    OK

  14. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 1 J/C - TRANSMISSION CONTROL ECU ASSEMBLY)


    1. Disconnect the transmission control ECU assembly connector.

    2. A003VCVE31
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *b to Transmission Control ECU Assembly

      Disconnect the engine room main wire from 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
      A71-2 (CANH) - A71-8 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (CAN NO. 1 J/C - TRANSMISSION CONTROL ECU ASSEMBLY)

    OK

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


    1. Disconnect the power management control ECU connector.

    2. A003VCVE32
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *b 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
      H141-4 (CANH) - H141-10 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (CAN NO. 1 J/C - POWER MANAGEMENT CONTROL ECU)

    OK

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


    1. A003VCVE33
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *b to ECM

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A71-1 (CANH) - A71-7 (CANL) Power switch off 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 1 J/C - ECM)

    OK

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


    1. Reconnect the instrument panel wire and engine room main wire to the CAN No. 1 junction connector.

    2. A003YN4E27
      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
      H44-6 (CANH) - H44-14 (CANL) Power switch off 54 to 69 Ω

      Note


      • The resistance must be measured after the main line connected ECUs (ECM and combination meter assembly), CAN No. 1 junction connector, CAN No. 2 junction connector and CAN No. 3 junction connector are reconnected.

      • The resistance must be measured after the CAN No. 1 junction connector branch line connected ECU are disconnected.


    NG

    REPLACE CAN NO. 1 JUNCTION CONNECTOR

    OK

  18. CHECK FOR SHORT IN CAN BUS LINES (ECU, SENSOR)


    1. A003YN4E27
      Text in Illustration
      *1 DLC3

      Connect the probes of an ohmmeter to terminals 6 (CANH) and 14 (CANL) of the DLC3.

    2. While observing the resistance value shown on the ohmmeter, reconnect each ECU and sensor connector until the resistance becomes abnormal (Below 54 Ω).

      Tech Tips

      If the resistance becomes abnormal when an ECU connector is reconnected, there may be a short in the ECU.


    NEXT

    REPLACE CORRESPONDING ECU OR SENSOR

  19. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 3 J/C - CAN NO. 2 J/C)


    1. Reconnect the wire harness connector to the CAN No. 2 junction connector rear side.

    2. A003VCVE34
      Text in Illustration
      *a

      Front view of wire harness connector

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

      Disconnect the instrument panel wire from the CAN No. 3 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition Connected to
      H142-5 (CANH) - H142-11 (CANL) Power switch off 108 to 132 Ω CAN No. 2 junction connector

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 2 J/C - CAN NO. 3 J/C)

    OK

  20. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 3 J/C - COMBINATION METER ASSEMBLY)


    1. A003VCVE35
      Text in Illustration
      *a

      Front view of wire harness connector

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

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition Connected to
      H142-6 (CANH) - H142-12 (CANL) Power switch off 108 to 132 Ω Combination meter assembly

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 3 J/C - COMBINATION METER ASSEMBLY)

    OK

  21. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 3 J/C - SKID CONTROL ECU)


    1. Disconnect the engine room main wire from the CAN No. 3 junction connector.

    2. Disconnect the skid control ECU (brake booster with master cylinder assembly) connector.

    3. A003VCVE36
      Text in Illustration
      *a

      Front view of wire harness connector

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

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A72-1 (CANH) - A72-7 (CANL) Power switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (CAN NO. 3 J/C - SKID CONTROL ECU)

    OK

  22. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 3 J/C)


    1. Reconnect the instrument panel wire and engine room main wire to the CAN No. 3 junction connector.

    2. A003YN4E27
      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
      H44-6 (CANH) - H44-14 (CANL) Power switch off 54 to 69 Ω

      Note


      • The resistance must be measured after the main line connected ECUs (ECM and combination meter assembly), CAN No. 1 junction connector, CAN No. 2 junction connector and CAN No. 3 junction connector are reconnected.

      • The resistance must be measured after the CAN No. 3 junction connector branch line connected ECU are disconnected.


    NG

    REPLACE CAN NO. 3 JUNCTION CONNECTOR

    OK

  23. CHECK FOR SHORT IN CAN BUS LINES (ECU, SENSOR)


    1. A003YN4E27
      Text in Illustration
      *1 DLC3

      Connect the probes of an ohmmeter to terminals 6 (CANH) and 14 (CANL) of the DLC3.

    2. While observing the resistance value shown on the ohmmeter, reconnect each ECU and sensor connector until the resistance becomes abnormal (Below 54 Ω).

      Tech Tips

      If the resistance becomes abnormal when an ECU connector is reconnected, there may be a short in the ECU.


    NEXT

    REPLACE CORRESPONDING ECU OR SENSOR