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

DESCRIPTION

There may be a short circuit between the CAN bus main wires and/or CAN branch wires 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

  • Combination meter

  • Yaw rate and acceleration sensor

  • Power steering ECU

  • Center airbag sensor assembly

  • Steering angle sensor

  • Air conditioning amplifier

  • Brake actuator (Skid control ECU)

  • Main body ECU (Passenger side junction block)

  • ECM

  • AFS ECU*1

  • CAN junction connector CTR

  • CAN No. 1 junction connector RH

  • CAN No. 2 junction connector

  • CAN No. 5 junction connector

Tech Tips

*1: w/ AFS

WIRING DIAGRAM

A01CC73E02
A01CGG3E03

INSPECTION PROCEDURE

Note


  • Turn the engine switch off before measuring the resistances of the CAN main wires and the CAN branch wires.

  • After the engine switch is turned off, check that the key reminder warning system and light reminder warning system are not in operation.

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

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 will help determine the cause of the malfunction.

PROCEDURE


  1. CHECK FOR SHORT IN CAN BUS WIRE (DLC3 BRANCH WIRE)


    1. Turn the engine switch off.

    2. A01CET0E06
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to CAN No. 1 Junction Connector RH)

      Disconnect the CAN branch wire connector (G66) from the CAN No. 1 junction connector RH (w/o earth terminal).

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.

    3. A01CEZIE01
      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
      G8-6 (CANH) - G8-14 (CANL) Engine switch off 1 MΩ or higher

    NG
    OK
  2. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 1 J/C RH - CAN NO. 5 J/C)


    1. Reconnect the CAN branch wire connector (G66) to the CAN No. 1 junction connector RH (w/o earth terminal).

    2. A01CFC1E16
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to CAN No. 1 Junction Connector RH)

      Disconnect the CAN main wire connector (G69) from the CAN No. 1 junction connector RH (w/o earth terminal).

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.

    3. A01CEZIE01
      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
      G8-6 (CANH) - G8-14 (CANL) Engine switch off 108 to 132 Ω
      Result
      Result Proceed to
      The resistance is still below 54 Ω when the specified connector is disconnected. (There is a short in the bus wires.) A
      The resistance becomes normal (between 108 to 132 Ω) when a connector is disconnected. (There is a short in the disconnected bus wires.) B

    B
    A
  3. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 1 J/C RH - CAN J/C CTR)


    1. Reconnect the CAN main wire connector (G69) to the CAN No. 1 junction connector RH (w/o earth terminal).

    2. A01CB89E08
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to CAN No. 1 Junction Connector RH)

      Disconnect the CAN main wire connector (G67) from the CAN No. 1 junction connector RH (w/o earth terminal).

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.

    3. A01CEZIE01
      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
      G8-6 (CANH) - G8-14 (CANL) Engine switch off 108 to 132 Ω
      Result
      Result Proceed to
      The resistance is still below 54 Ω when the specified connector is disconnected. (There is a short in the bus wires.) A
      The resistance becomes normal (between 108 to 132 Ω) when a connector is disconnected. (There is a short in the disconnected bus wires.) B

    B
    A
  4. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 1 J/C RH)


    1. A01CEZIE01
      Text in Illustration
      *1 DLC3

      Connect the probes of an ohmmeter to terminals CANH and CANL of the DLC3.

    2. While observing the resistance value shown on the tester, disconnect connector (G65) from the CAN No. 1 junction connector RH one by one until the resistance becomes normal (between 54 and 69 Ω).

      Tech Tips

      Disconnect the branch wire connectors other than those of the DLC3.

      A01CFGME01
      for CAN Junction Connector B Side
      Terminal No. (Symbol) Wiring Color Connected to
      G65-1 (CANH) SB Power steering ECU
      G65-2 (CANL) W
      G66-1 (CANH) GR DLC3
      G66-2 (CANL) W
      G67-1 (CANH) SB CAN junction connector CTR
      G67-2 (CANL) W
      G69-1 (CANH) B CAN No. 5 junction connector
      G69-2 (CANL) W
      Text in Illustration
      *1 CAN No. 1 Junction Connector RH - -
      *a Junction Connector B Side *b Junction Connector A Side
      *c

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector RH)

      *d Earth Terminal

      Note

      Do not reconnect the disconnected connectors until this inspection is complete because there may be a short in 2 or more branch wires.

      Result
      Result Proceed to
      The resistance is still below 54 Ω when all the specified connectors are disconnected. (There is no short in the branch wires.) A
      The resistance becomes normal (between 54 and 69 Ω) when a connector is disconnected. (There is a short in one or more of the branch wires.) B
    3. When there is a short in one or more of the branch wires:


      1. Reconnect all of the connectors to the CAN junction connector, except for the one that was disconnected last (the short-circuited bus wire). Check that the resistance shown on the tester becomes normal (between 54 and 69 Ω) to confirm that there is a short in the only one branch wire.

        Tech Tips


        • The shape of connectors connected to the CAN junction connector which has an earth terminal is the same. The connectors connected to the CAN junction connector can be distinguished by the colors of the bus wire and the connecting side of the junction connector.

        • Reconnecting the connectors to non-specified positions on the CAN junction connector does not affect system operation. However, it is preferred to reconnect the connectors to their specified positions to avoid negative effects on the wiring such as tension on the wiring harnesses, and to make future maintenance easier.


    B
    A
  5. CHECK FOR SHORT IN CAN BUS WIRE


    1. Reconnect the CAN main wire connector (G67) to the CAN No. 1 junction connector RH (w/o earth terminal).

    2. Reconnect the CAN main wire connector (G69) to the CAN No. 1 junction connector RH (w/o earth terminal).

    3. Reconnect the connector for the short-circuited branch wire to the CAN junction connector (the connector that caused the bus wire resistance to become normal (between 54 and 69 Ω) when it was disconnected).

    4. Disconnect the connector that includes terminals CANH and CANL from the ECU to which the short-circuited branch wire is connected.

    5. A01CEZIE01
      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
      G8-6 (CANH) - G8-14 (CANL) Engine switch off 54 to 69 Ω

      Tech Tips

      If the resistance becomes normal (between 54 and 69 Ω) when the connector is disconnected from the ECU, there may be a short in the ECU.


    NG
    OK
  6. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 1 J/C RH - CAN NO. 5 J/C)


    1. A01CFKWE15
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 5 Junction Connector)

      Disconnect the connector of the CAN No. 5 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      M22-6 (CANH) - M22-17 (CANL) Engine switch off 1 MΩ or higher

    NG
    OK
  7. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 5 J/C - COMBINATION METER)


    1. A01CGINE17
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 5 Junction Connector)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      M22-7 (CANH) - M22-18 (CANL) Engine switch off 108 to 132 Ω

    NG
    OK
  8. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 5 J/C - YAW RATE AND ACCELERATION SENSOR)


    1. A01CBZBE05
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Yaw Rate and Acceleration Sensor)

      Disconnect the connector of the yaw rate and acceleration sensor.

    2. A01CFKWE16
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 5 Junction Connector)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      M22-5 (CANH) - M22-16 (CANL) Engine switch off 1 MΩ or higher

    NG
    OK
  9. CHECK FOR SHORT IN CAN BUS WIRE (YAW RATE AND ACCELERATION SENSOR)


    1. Reconnect the CAN main wire connector (G69) to the CAN No. 1 junction connector RH (w/o earth terminal).

    2. Reconnect the connector of the CAN No. 5 junction connector.

    3. A01CEZIE01
      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
      G8-6 (CANH) - G8-14 (CANL) Engine switch off 54 Ω or higher

    NG
    OK
  10. CHECK FOR SHORT IN CAN BUS WIRE (COMBINATION METER)


    1. A01CD9PE97
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Combination Meter)

      Disconnect the connector of the combination meter.

    2. A01CGINE17
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 5 Junction Connector)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      M22-7 (CANH) - M22-18 (CANL) Engine switch off 1 MΩ or higher

    NG
    OK
  11. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 1 J/C RH - CAN J/C CTR)


    1. A01CFC1E17
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to CAN Junction Connector CTR)

      Disconnect the CAN main wire connector (G62) from the CAN junction connector CTR (w/o earth terminal).

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      G62-1 (CANH) - G62-2 (CANL) Engine switch off 1 MΩ or higher

    NG
    OK
  12. CHECK FOR SHORT IN CAN BUS WIRE (CAN J/C CTR - CAN NO. 2 J/C)


    1. A01CD8NE11
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to CAN Junction Connector CTR)

      Disconnect the CAN main wire connector (G61) from the CAN junction connector CTR (w/o earth terminal).

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      G61-1 (CANH) - G61-2 (CANL) Engine switch off 108 to 132 Ω

    NG
    OK
  13. CHECK FOR SHORT IN CAN BUS WIRE (CAN J/C CTR)


    1. A01CEZIE01
      Text in Illustration
      *1 DLC3

      Connect the probes of an ohmmeter to terminals CANH and CANL of the DLC3.

    2. While observing the resistance value shown on the tester, disconnect connectors (G63 and G64) from the CAN junction connector CTR one by one until the resistance becomes normal (between 54 and 69 Ω).

      Tech Tips

      Disconnect the branch wire connectors other than those of the DLC3.

      A01CB33E03
      for CAN Junction Connector B Side
      Terminal No. (Symbol) Wiring Color Connected to
      G61-1 (CANH) B CAN No. 2 junction connector
      G61-2 (CANL) W
      G62-1 (CANH) SB CAN No. 1 junction connector RH
      G62-2 (CANL) W
      G63-1 (CANH) Y Center airbag sensor assembly
      G63-2 (CANL) W
      G64-1 (CANH) BR Steering angle sensor
      G64-2 (CANL) W
      Text in Illustration
      *1 CAN Junction Connector CTR - -
      *a Junction Connector B Side *b Junction Connector A Side
      *c

      Front view of wire harness connector

      (to CAN Junction Connector CTR)

      *d Earth Terminal

      Note

      Do not reconnect the disconnected connectors until this inspection is complete because there may be a short in 2 or more branch wires.

      Result
      Result Proceed to
      The resistance is still below 54 Ω when all the specified connectors are disconnected. (There is no short in the branch wires.) A
      The resistance becomes normal (between 54 and 69 Ω) when a connector is disconnected. (There is a short in one or more of the branch wires.) B
    3. When there is a short in one or more of the branch wires:


      1. Reconnect all of the connectors to the CAN junction connector, except for the one that was disconnected last (the short-circuited bus wire). Check that the resistance shown on the tester becomes normal (between 54 and 69 Ω) to confirm that there is a short in the only one branch wire.

        Tech Tips


        • The shape of connectors connected to the CAN junction connector which has an earth terminal is the same. The connectors connected to the CAN junction connector can be distinguished by the colors of the bus wire and the connecting side of the junction connector.

        • Reconnecting the connectors to non-specified positions on the CAN junction connector does not affect system operation. However, it is preferred to reconnect the connectors to their specified positions to avoid negative effects on the wiring such as tension on the wiring harnesses, and to make future maintenance easier.


    B
    A
  14. CHECK FOR SHORT IN CAN BUS WIRE


    1. Reconnect the CAN main wire connector (G61 and G62) to the CAN junction connector CTR (w/o earth terminal).

    2. Reconnect the CAN main wire connector (G67) to the CAN No. 1 junction connector RH (w/o earth terminal).

    3. Reconnect the connector of the short-circuited branch wire to the CAN junction connector (the connector that caused the bus wire resistance to become normal (between 54 and 69 Ω) when it was disconnected).

    4. Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the short-circuited branch wire is connected.

    5. A01CEZIE01
      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
      G8-6 (CANH) - G8-14 (CANL) Engine switch off 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.


    NG
    OK
  15. CHECK FOR SHORT IN CAN BUS WIRE (CAN J/C CTR - CAN NO. 2 J/C)


    1. A01CFKWE05
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)

      Disconnect the connector of the CAN No. 2 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      G56-5 (CANH) - G56-16 (CANL) Engine switch off 1 MΩ or higher

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


    1. A01CFKWE06
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      G56-1 (CANH) - G56-12 (CANL) Engine switch off 108 to 132 Ω

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


    1. A01CFJZE88
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU)

      Disconnect the connector of the skid control ECU.

    2. A01CFKWE07
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      G56-2 (CANH) - G56-13 (CANL) Engine switch off 1 MΩ or higher

    NG
    OK
  18. CHECK FOR SHORT IN CAN BUS WIRE (SKID CONTROL ECU)


    1. Reconnect the CAN main wire connector (G67) to the CAN No. 1 junction connector RH (w/o earth terminal).

    2. Reconnect the CAN main wire connectors (G61 and G62) to the CAN junction connector CTR (w/o earth terminal).

    3. Reconnect the connector of the CAN No. 2 junction connector.

    4. A01CEZIE01
      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
      G8-6 (CANH) - G8-14 (CANL) Engine switch off 54 Ω or higher

    NG
    OK
  19. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 2 J/C - AIR CONDITIONING AMPLIFIER)


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

    2. A01CD9PE98
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Air Conditioning Amplifier)

      Disconnect the connector of the air conditioning amplifier.

    3. A01CFKWE08
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      G56-4 (CANH) - G56-15 (CANL) Engine switch off 1 MΩ or higher

    NG
    OK
  20. CHECK FOR SHORT IN CAN BUS WIRE (AIR CONDITIONING AMPLIFIER)


    1. Reconnect the connector of the CAN No. 2 junction connector.

    2. A01CEZIE01
      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
      G8-6 (CANH) - G8-14 (CANL) Engine switch off 54 to 69 Ω

    NG
    OK
  21. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 2 J/C - AFS ECU)

    Tech Tips

    For vehicles without a headlight swivel ECU (AFS ECU), go to "CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 2 J/C - MAIN BODY ECU)".


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

    2. A01CG90E40
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Headlight Swivel ECU)

      Disconnect the connector of the headlight swivel ECU (AFS ECU).

    3. A01CF9VE03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      G56-7 (CANH) - G56-18 (CANL) Engine switch off 1 MΩ or higher

    NG
    OK
  22. CHECK FOR SHORT IN CAN BUS WIRE (AFS ECU)


    1. Reconnect the connector of the CAN No. 2 junction connector.

    2. A01CEZIE01
      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
      G8-6 (CANH) - G8-14 (CANL) Engine switch off 54 to 69 Ω

    NG
    OK
  23. CHECK FOR SHORT IN CAN BUS WIRE (CAN NO. 2 J/C - MAIN BODY ECU)


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

    2. A01CGFNE13
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Main Body ECU)

      Disconnect the connector of the main body ECU.

    3. A01CFKWE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      G56-3 (CANH) - G56-14 (CANL) Engine switch off 1 MΩ or higher

    NG
    OK
  24. CHECK FOR SHORT IN CAN BUS WIRE (MAIN BODY ECU)


    1. Reconnect the connector of the CAN No. 2 junction connector.

    2. A01CEZIE01
      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
      G8-6 (CANH) - G8-14 (CANL) Engine switch off 54 to 69 Ω

    NG
    OK
  25. CHECK FOR SHORT IN CAN BUS WIRE (ECM)


    1. A01CD8TE66
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the connector of the ECM.

    2. A01CFKWE06
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      G56-1 (CANH) - G56-12 (CANL) Engine switch off 1 MΩ or higher
      Result
      Result Proceed to
      OK (for 2AZ-FE) A
      OK (for 2GR-FE) B
      NG C

    B
    C
    A