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

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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.
  1. Short in CAN bus main wire
  2. Short in CAN bus branch wire
  3. Power management control ECU
  4. ECM
  5. Main body ECU
  6. Combination meter
  7. Skid control ECU (Brake booster with master cylinder)
  8. Steering angle sensor
  9. Yaw rate sensor
  10. Power steering ECU
  11. Center airbag sensor assembly
  12. Transmission control ECU
  13. Certification ECU
  14. Navigation ECU (Navigation receiver assembly)
  15. CAN No. 1 junction connector
  16. CAN No. 2 junction connector

WIRING DIAGRAM


C210880E05


C210881E05


INSPECTION PROCEDURE

NOTICE:
  1. Turn the power switch off before measuring the resistances between CAN bus main wires and between CAN bus branch wires.
  2. Turn the power switch off before inspecting CAN bus wires for a ground short.
  3. After the power switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.
  4. 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.

HINT:
  1. 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.
  2. 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.

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

  1. Turn the power switch off.



    C210276E54

  1. Disconnect the CAN No. 2 junction connector.
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to CAN No. 2 Junction Connector)
    *2
    		to CAN No. 1 Junction Connector

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L95-6 (CANH) - L95-17 (CANL)
    		Power switch off
    		108 to 132 Ω



NG
Go to step 11
OK


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


    C210276E43

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L95-9 (CANH) - L95-20 (CANL)
    		Power switch off
    		108 to 132 Ω

    *1
    		Front view of wire harness connector
    (to CAN No. 2 Junction Connector)
    *2
    		to ECM



NG
Go to step 20
OK


3.CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 2 J/C - DLC3)


    C210276E55

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L95-4 (CANH) - L95-15 (CANL)
    		Power switch off
    		1 MΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to CAN No. 2 Junction Connector)
    *2
    		to DLC3



NG
REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DLC3
OK


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


    C209401E11

  1. Disconnect the skid control ECU (brake booster with master cylinder) connector.
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Skid Control ECU)



    C210276E56

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L95-3 (CANH) - L95-14 (CANL)
    		Power switch off
    		1 MΩ or higher

    Text in Illustration 
    *2
    		Front view of wire harness connector
    (to CAN No. 2 Junction Connector)
    *3
    		to Skid Control ECU



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


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

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



  1. for HDD:



      C209582E02

    1. Disconnect the navigation ECU connector.
      Text in Illustration 
      *1
      		Front view of wire harness connector
      (to Navigation ECU)



  1. for DVD:



      E168565E31

    1. Disconnect the navigation ECU connector.
      Text in Illustration 
      *1
      		Front view of wire harness connector
      (to Navigation ECU)



    C234350E01

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L95-5(CANH) - L95-16(CANL)
    		Power switch off
    		1 MΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to CAN No. 2 Junction Connector)
    *2
    		to Navigation ECU



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


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


    C185765E38

  1. Disconnect the steering angle sensor connector.
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Steering Angle Sensor)



    C210276E58

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L95-1 (CANH) - L95-12 (CANL)
    		Power switch off
    		1 MΩ or higher

    Text in Illustration 
    *2
    		Front view of wire harness connector
    (to CAN No. 2 Junction Connector)
    *3
    		to Steering Angle Sensor



NG
REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 2 J/C - STEERING ANGLE SENSOR)
OK


7.CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 2 J/C - POWER STEERING ECU)


    C188242E12

  1. Disconnect the power steering ECU connector.
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Power Steering ECU)



    C210276E59

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L95-2 (CANH) - L95-13 (CANL)
    		Power switch off
    		1 MΩ or higher

    Text in Illustration 
    *2
    		Front view of wire harness connector
    (to CAN No. 2 Junction Connector)
    *3
    		to Power Steering ECU



NG
REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 2 J/C - POWER STEERING ECU)
OK


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


    C201680E09

  1. Disconnect the certification ECU connector.
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Certification ECU)



    C210276E38

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L95-7 (CANH) - L95-18 (CANL)
    		Power switch off
    		108 to 132 Ω

    Text in Illustration 
    *2
    		Front view of wire harness connector
    (to CAN No. 2 Junction Connector)
    *3
    		to Certification ECU



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


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

  1. Reconnect the CAN No. 2 junction connector.



    C210421E01

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L61-6 (CANH) - L61-14 (CANL)
    		Power switch off
    		54 to 69 Ω

    Text in Illustration 
    *1
    		DLC3

    NOTICE:
    1. The resistance must be measured after the main wire connected ECUs (ECM and combination meter), CAN No. 1 junction connector and No. 2 junction connector are reconnected.
    2. The resistance must be measured after the CAN No. 2 junction connector branch wire connected ECU and sensor connectors are disconnected.



NG
REPLACE CAN NO. 2 JUNCTION CONNECTOR
OK


10.CHECK FOR SHORT IN CAN BUS WIRES (ECU, SENSOR)


    C210421E01

  1. Connect the probes of an ohmmeter to terminals 6 (CANH) and 14 (CANL) of the DLC3.
    Text in Illustration 
    *1
    		DLC3

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

    HINT:
    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 

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

  1. Reconnect the CAN No. 2 junction connector.



    C210276E60

  1. Disconnect the CAN No. 1 junction connector.

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L94-3 (CANH) - L94-14 (CANL)
    		Power switch off
    		108 to 132 Ω

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to CAN No. 1 Junction Connector)
    *2
    		to CAN No. 2 Junction Connector



NG
REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 J/C - CAN NO. 2 JUNCTION CONNECTOR)
OK


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


    C210276E26

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L94-1 (CANH) - L94-12 (CANL)
    		Power switch off
    		108 to 132 Ω

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to CAN No. 1 Junction Connector)
    *2
    		to Combination Meter



NG
Go to step 21
OK


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


    A204446E06

  1. Disconnect the power management control ECU connector.
    Text in Illustration 
    *1
    		Rear view of wire harness connector
    (to Power Management Control ECU)



    C210276E42

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L94-6 (CANH) - L94-17 (CANL)
    		Power switch off
    		1 MΩ or higher

    Text in Illustration 
    *2
    		Front view of wire harness connector
    (to CAN No. 1 Junction Connector)
    *3
    		to Power Management Control ECU



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


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


    C210476E01

  1. Disconnect the transmission control ECU connector.
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Transmission Control ECU)



    C210276E61

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L94-7 (CANH) - L94-18 (CANL)
    		Power switch off
    		1 MΩ or higher

    Text in Illustration 
    *2
    		Front view of wire harness connector
    (to CAN No. 2 Junction Connector)
    *3
    		to Transmission Control ECU



NG
REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 1 J/C - TRANSSMISSION CONTROL ECU)
OK


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


    C165630E15

  1. Disconnect the yaw rate sensor connector.
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Yaw Rate Sensor)



    C210276E31

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L94-4 (CANH) - L94-15 (CANL)
    		Power switch off
    		1 MΩ or higher

    Text in Illustration 
    *2
    		Front view of wire harness connector
    (to CAN No. 1 Junction Connector)
    *3
    		to Yaw Rate Sensor



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


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


    C188243E14

  1. Disconnect the center airbag sensor assembly connector.
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Center Airbag Sensor Assembly)



    C210276E62

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L94-5 (CANH) - L94-16 (CANL)
    		Power switch off
    		1 MΩ or higher

    Text in Illustration 
    *2
    		Front view of wire harness connector
    (to CAN No. 1 Junction Connector)
    *3
    		to Center Airbag Sensor Assembly



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


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


    C204895E02

  1. Disconnect the main body ECU connector.
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Main Body ECU)



    C210276E63

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L94-2 (CANH) - L94-13 (CANL)
    		Power switch off
    		1 MΩ or higher

    Text in Illustration 
    *2
    		Front view of wire harness connector
    (to CAN No. 1 Junction Connector)
    *3
    		to Main Body ECU



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


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

  1. Reconnect the CAN No. 1 junction connector.



    C210421E01

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L61-6 (CANH) - L61-14 (CANL)
    		Power switch off
    		54 to 69 Ω

    Text in Illustration 
    *1
    		DLC3

    NOTICE:
    1. The resistance must be measured after the main wire connected ECUs (ECM and combination meter), CAN No. 1 junction connector and No. 2 junction connector are reconnected.
    2. The resistance must be measured after the CAN No. 1 junction connector branch wire connected ECU and sensor connectors are disconnected.



NG
REPLACE CAN NO. 1 JUNCTION CONNECTOR
OK


19.CHECK FOR SHORT IN CAN BUS WIRES (ECU, SENSOR)


    C210421E01

  1. Connect the probes of an ohmmeter to terminals 6 (CANH) and 14 (CANL) of the DLC3.
    Text in Illustration 
    *1
    		DLC3

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

    HINT:
    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 WIRES (ECM)


    A192807E26

  1. Disconnect the ECM connector.
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to ECM)



    C210276E40

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L95-9 (CANH) - L95-20 (CANL)
    		Power switch off
    		1 MΩ or higher

    Text in Illustration 
    *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)  

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


    C188241E26

  1. Disconnect the combination meter connector.
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Combination Meter)



    C210276E41

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    L94-1 (CANH) - L94-12 (CANL)
    		Power switch off
    		1 MΩ or higher

    Text in Illustration 
    *2
    		Front view of wire harness connector
    (to CAN No. 1 Junction Connector)
    *3
    		to Combination Meter



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

REPLACE METER CIRCUIT PLATE NO. 3 (COMBINATION METER ECU) (Click here)