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

  • Radio receiver assembly*1*2

  • DCM (Telematics transceiver)*3

  • CAN No. 1 junction connector

  • CAN No. 2 junction connector

  • CAN No. 3 junction connector

*1: for Navigation Receiver Type

*2: for Radio and Display Type

*3: w/ Manual (SOS) Switch

WIRING DIAGRAM

A004WIME04
A004WY5E05

CAUTION / NOTICE / HINT

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

    2. A004W79E02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the A60 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A60-13 (CANH) - A60-5 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Result Proceed to
      OK (for 2ZR-FXE) A
      OK (for 5ZR-FXE) B
      NG C

    A

    REPLACE ECM Click here

    B

    REPLACE ECM Click here

    C

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


    1. Reconnect the A60 ECM connector.

    2. A004XPNE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Combination Meter Assembly)

      Disconnect the H19 combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H19-32 (CANH) - H19-31 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

    NG

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


    1. Reconnect the H19 combination meter assembly connector.

    2. A004XKME02
      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 H104 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 Condition Specified Condition Connected to
      H104-1 (CANH) - H104-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω CAN No. 1 junction connector
      H104-4 (CANH) - H104-5 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω CAN No. 3 junction connector
      H104-7 (CANH) - H104-8 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 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 H25 power steering ECU assembly connector.

    2. A004VXVE02
      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 Condition Specified Condition
      H104-10 (CANH) - H104-11 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 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 - RADIO RECEIVER ASSEMBLY)

    Tech Tips

    For vehicles except the navigation receiver type, go to the next step.


    1. Disconnect the H147 radio receiver assembly connector connector.

    2. A004Y4UE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *b to Radio Receiver Assembly

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H104-13 (CANH) - H104-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher

    NG

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

    OK

  6. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 2 J/C - RADIO RECEIVER ASSEMBLY)

    Tech Tips

    For vehicles except the radio and display type, go to the next step.


    1. Disconnect the H164 radio receiver assembly connector.

    2. A004Y4UE03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *b to Radio Receiver Assembly

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H104-13 (CANH) - H104-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher

    NG

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

    OK

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


    1. Disconnect the H105 connector from the CAN No. 2 junction connector front side.

    2. Disconnect the H87 yaw rate and acceleration sensor connector.

    3. A004ZF7E02
      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 Condition Specified Condition
      H105-12 (CANH) - H105-11 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher

    NG

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

    OK

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


    1. Disconnect the H29 steering angle sensor (spiral cable with sensor sub-assembly) connector.

    2. A004VC4E02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *b to Steering Angle Sensor (Spiral Cable with Sensor Sub-assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H105-3 (CANH) - H105-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher

    NG

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

    OK

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


    1. Disconnect the H84 airbag sensor assembly connector.

    2. A004W2TE02
      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 Condition Specified Condition
      H105-9 (CANH) - H105-8 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher

    NG

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

    OK

  10. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 2 J/C - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))


    1. Disconnect the H1 certification ECU (smart key ECU assembly) connector.

    2. A004WH7E02
      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 Condition Specified Condition
      H105-6 (CANH) - H105-5 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher

    NG

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

    OK

  11. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 2 J/C - DCM (TELEMATICS TRANSCEIVER))


    1. Disconnect the H145 DCM (telematics transceiver) connector.

    2. A004ZLZE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *b to DCM (Telematics Transceiver)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H105-15 (CANH) - H105-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (CAN NO. 2 J/C - DCM (TELEMATICS TRANSCEIVER))

    OK

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


    1. Reconnect the H104 and H105 connectors to the CAN No. 2 junction connector front side and rear side.

    2. A004Y9HE03
      Text in Illustration
      *1 DLC3

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H44-6 (CANH) - H44-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 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

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


    1. A004Y9HE04
      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

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


    1. Reconnect the H104 connector to the CAN No. 2 junction connector rear side.

    2. A004ZHUE02
      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 H112 connector from the CAN No. 1 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H112-6 (CANH) - H112-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 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

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


    1. Disconnect the H16 main body ECU (multiplex network body ECU) connector.

    2. A004YJGE02
      Text in Illustration
      *a

      Front view of wire harness connector

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H112-5 (CANH) - H112-11 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher

    NG

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

    OK

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


    1. Disconnect the A57 connector from the CAN No. 1 junction connector.

    2. Disconnect the A61 skid control ECU (brake booster with master cylinder assembly) connector.

    3. A004VNWE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *b to Skid Control ECU (Brake Booster with Master Cylinder Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A57-2 (CANH) - A57-8 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher

    NG

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

    OK

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


    1. A004W9TE02
      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
      A57-1 (CANH) - A57-7 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    NG

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

    OK

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


    1. Reconnect the A57 and H112 connectors to the CAN No. 1 junction connectors.

    2. A004Y9HE05
      Text in Illustration
      *1 DLC3

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H44-6 (CANH) - H44-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 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

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


    1. A004Y9HE05
      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

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


    1. Reconnect the H104 connector to the CAN No. 2 junction connector rear side.

    2. A004WGBE02
      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 H113 connector from the CAN No. 3 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      H113-5 (CANH) - H113-11 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 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

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


    1. A004XEEE02
      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 Condition Specified Condition Connected to
      H113-6 (CANH) - H113-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 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

  22. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 3 J/C - POWER MANAGEMENT CONTROL ECU)


    1. Disconnect the H4 power management control ECU connector.

    2. A004XW9E02
      Text in Illustration
      *a

      Front view of wire harness connector

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H113-4 (CANH) - H113-10 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher

    NG

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

    OK

  23. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 3 J/C - TRANSMISSION CONTROL ECU ASSEMBLY)


    1. Disconnect the A22 transmission control ECU assembly connector.

    2. A004YI3E02
      Text in Illustration
      *a

      Front view of wire harness connector

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

      Disconnect the A58 connector from the CAN No. 3 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A58-1 (CANH) - A58-7 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher

    NG

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

    OK

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


    1. Reconnect the A58 and H113 connectors to the CAN No. 3 junction connector.

    2. A004Y9HE05
      Text in Illustration
      *1 DLC3

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H44-6 (CANH) - H44-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 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

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


    1. A004Y9HE05
      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