CAN COMMUNICATION SYSTEM Open in One Side of CAN Branch Line

DESCRIPTION

If 2 or more ECUs and/or sensors do not appear on the intelligent tester "Bus Check" screen, one side of the CAN branch wire may be open (one side of the CANH [CAN branch wire]/CANL [CAN branch wire] of the ECU and/or sensor is open).

Symptom Trouble Area
2 or more ECUs and/or sensors do not appear on the intelligent tester "Bus Check" screen.

  • Brake actuator assembly (VSC ECU)

  • Certification ECU*1

  • Air conditioning amplifier assembly*2

  • Spiral cable sub-assembly (steering angle sensor)

  • Yaw rate sensor

  • Main body ECU (instrument panel junction block assembly)

  • Center airbag sensor assembly

  • Power management control ECU*1

  • Power steering ECU assembly

  • Radio and display receiver assembly*3

WIRING DIAGRAM

A01ISLVE01
A01INJKE03

INSPECTION PROCEDURE

Note


  • For vehicles with an entry and start system:

    Before replacing the certification ECU (smart key ECU assembly), refer to the entry and start system (for Entry Function) Click here.

  • After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work Click here.

Tech Tips


  • Perform the following inspection for the ECUs (sensors) which are not displayed on the intelligent tester. If a malfunction cannot be identified, perform the following inspections for the ECUs (sensors) connected to the CAN communication system.

  • Do not remove the combination meter assembly and ECM, as they are the end parts of the circuit. If removed, CAN communication will not be possible.

  • The open circuit confirmation of the combination meter assembly, ECM and main wire is performed in the Check CAN Bus Line procedure of "How to Proceed with Troubleshooting". This inspection only has procedures for checking for an open circuit on one side of the CAN branch wire.

PROCEDURE


  1. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (BRAKE ACTUATOR ASSEMBLY)


    1. Disconnect the A52*1 or A54*2 brake actuator assembly (VSC ECU) connector.


      • *1: for AD Series Engine

      • *2: for ZR Series Engine

    2. Select "Bus Check" on the intelligent tester Click here.

      Result
      Result Proceed to
      "Skid Control (ABS/VSC/TRAC)" not displayed on the intelligent tester. A
      Several ECUs and sensors in addition to "Skid Control (ABS/VSC/TRAC)" not displayed on the intelligent tester. B

    B

    CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (MAIN BODY ECU) Click here

    A

  2. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (BRAKE ACTUATOR ASSEMBLY CAN BRANCH WIRE)


    1. A01IQ6CE04
      Text in Illustration
      *1 for AD Series Engine
      *2 for ZR Series Engine
      *3

      Front view of wire harness connector

      (to Brake Actuator Assembly)

      Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.

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

      Standard Resistance
      for AD Series Engine
      Tester Connection Switch Condition Specified Condition
      A52-35 (CANH) - A52-14 (CANL) Ignition switch off 54 to 69 Ω
      for ZR Series Engine
      Tester Connection Switch Condition Specified Condition
      A54-35 (CANH) - A54-14 (CANL) Ignition switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (BRAKE ACTUATOR ASSEMBLY)

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY (VSC ECU) Click here

  3. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (MAIN BODY ECU)


    1. Disconnect the H81 main body ECU (instrument panel junction block assembly) connector.

    2. Select "Bus Check" on the intelligent tester Click here.

      Result
      Result Proceed to
      "Main Body" not displayed on the intelligent tester. A
      Several ECUs and sensors in addition to "Main Body" not displayed on the intelligent tester. B

    B

    CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (YAW RATE SENSOR) Click here

    A

  4. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (MAIN BODY ECU CAN BRANCH WIRE)


    1. A01IN0UE03
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to Main Body ECU)

      Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H81-15 (CANH) - H81-16 (CANL) Ignition switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (MAIN BODY ECU)

    OK

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

  5. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (YAW RATE SENSOR)


    1. Disconnect the H68 yaw rate sensor connector.

    2. Select "Bus Check" on the intelligent tester Click here.

      Result
      Result Proceed to
      "Yaw Rate Sensor" not displayed on the intelligent tester. A
      Several ECUs and sensors in addition to "Yaw Rate Sensor" not displayed on the intelligent tester. B

    B

    CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (SPIRAL CABLE SUB-ASSEMBLY) Click here

    A

  6. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (YAW RATE SENSOR CAN BRANCH WIRE)


    1. A01IPT7E08
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Yaw Rate Sensor)

      Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H68-2 (CANH) - H68-3 (CANL) Ignition switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (YAW RATE SENSOR)

    OK

    REPLACE YAW RATE SENSOR Click here

  7. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (SPIRAL CABLE SUB-ASSEMBLY)


    1. Disconnect the H69 spiral cable sub-assembly (steering angle sensor) connector.

    2. Select "Bus Check" on the intelligent tester Click here.

      Result
      Result Proceed to
      "Spiral cable (Steering Angle Sensor)" not displayed on the intelligent tester. A
      Several ECUs and sensors in addition to "Spiral cable (Steering Angle Sensor)" not displayed on the intelligent tester. B

    B

    CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (POWER STEERING ECU ASSEMBLY) Click here

    A

  8. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (SPIRAL CABLE SUB-ASSEMBLY CAN BRANCH WIRE)


    1. A01IPSCE05
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to Spiral Cable Sub-assembly)

      Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H69-4 (CANH) - H69-3 (CANL) Ignition switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (SPIRAL CABLE SUB-ASSEMBLY)

    OK

    REPLACE SPIRAL CABLE SUB-ASSEMBLY (STEERING ANGLE SENSOR) Click here

  9. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (POWER STEERING ECU ASSEMBLY)


    1. Disconnect the H49 power steering ECU assembly connector.

    2. Select "Bus Check" on the intelligent tester Click here.

      Result
      Result Proceed to
      "Power Steering (EPS)" not displayed on the intelligent tester. A
      Several ECUs and sensors in addition to "Power Steering (EPS)" not displayed on the intelligent tester. B

    B

    CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (RADIO AND DISPLAY RECEIVER ASSEMBLY) Click here

    A

  10. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (POWER STEERING ECU ASSEMBLY CAN BRANCH WIRE)


    1. A01IRTBE03
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

      Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H49-2 (CANH) - H49-8 (CANL) Ignition switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (POWER STEERING ECU)

    OK

    REPLACE POWER STEERING ECU ASSEMBLY Click here

  11. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (RADIO AND DISPLAY RECEIVER ASSEMBLY)

    Note

    For vehicles without a radio and display receiver type, go to "Check for Open in One Side of CAN Branch Wire (Air Conditioning Amplifier Assembly)".


    1. Disconnect the H105 radio and display receiver assembly connector.

    2. Select "Bus Check" on the intelligent tester Click here.

      Result
      Result Proceed to
      "Display and Navigation (AVN1)" not displayed on the intelligent tester. A
      Several ECUs and sensors in addition to "Display and Navigation (AVN1)" not displayed on the intelligent tester. B

    B

    CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (AIR CONDITIONING AMPLIFIER ASSEMBLY) Click here

    A

  12. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (RADIO AND DISPLAY RECEIVER ASSEMBLY CAN BRANCH WIRE)


    1. A01ISS8E03
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Radio and Display Receiver Assembly)

      Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H105-9 (CANH) - H105-10 (CANL) Ignition switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (RADIO AND DISPLAY RECEIVER ASSEMBLY)

    OK

    REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY

  13. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (AIR CONDITIONING AMPLIFIER ASSEMBLY)

    Note

    For vehicles with an entry and start system, go to "Check for Open in One Side of CAN Branch Wire (Certification ECU)".


    1. Disconnect the H46*1 or H9*2 air conditioning amplifier assembly connector.


      • *1: for Automatic Air Conditioning System

      • *2: for Manual Air Conditioning System or w/o Air Conditioning System

    2. Select "Bus Check" on the intelligent tester Click here.

      Result
      Result Proceed to
      "Air Conditioning Amplifier" not displayed on the intelligent tester. A
      Several ECUs and sensors in addition to "Air Conditioning Amplifier" not displayed on the intelligent tester. B

    B

    CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (CERTIFICATION ECU) Click here

    A

  14. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (AIR CONDITIONING AMPLIFIER ASSEMBLY CAN BRANCH WIRE)


    1. A01IOPRE01
      Text in Illustration
      *1 for Automatic Air Conditioning System
      *2 for Manual Air Conditioning System or w/o Air Conditioning System
      *3

      Front view of wire harness connector

      (to Air Conditioning Amplifier Assembly)

      Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.

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

      Standard Resistance
      for Automatic Air Conditioning System
      Tester Connection Switch Condition Specified Condition
      H46-11 (CANH) - H46-12 (CANL) Ignition switch off 54 to 69 Ω
      for Manual Air Conditioning System or w/o Air Conditioning System
      Tester Connection Switch Condition Specified Condition
      H9-2 (CANH) - H9-3 (CANL) Ignition switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY)

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  15. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (CERTIFICATION ECU)

    Note

    For vehicles without an entry and start system, go to "Check for Open in One Side of CAN Branch Wire (Center Airbag Sensor Assembly)".


    1. Disconnect the H51 certification ECU connector.

    2. Select "Bus Check" on the intelligent tester Click here.

      Result
      Result Proceed to
      "Certification (Smart)" not displayed on the intelligent tester. A
      Several ECUs and sensors in addition to "Certification (Smart)" not displayed on the intelligent tester. B

    B

    CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (POWER MANAGEMENT CONTROL ECU) Click here

    A

  16. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (CERTIFICATION ECU CAN BRANCH WIRE)


    1. A01ISYUE04
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to Certification ECU)

      Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H51-9 (CANH) - H51-10 (CANL) Ignition switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CERTIFICATION ECU)

    OK

    REPLACE CERTIFICATION ECU

  17. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (POWER MANAGEMENT CONTROL ECU)


    1. Disconnect the H71 power management control ECU connector.

    2. Select "Bus Check" on the intelligent tester Click here.

      Result
      Result Proceed to
      "Power Management1" not displayed on the intelligent tester. A
      Several ECUs and sensors in addition to "Power Management1" not displayed on the intelligent tester. B

    B

    CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (CENTER AIRBAG SENSOR ASSEMBLY CAN BRANCH WIRE) Click here

    A

  18. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (POWER MANAGEMENT CONTROL ECU CAN BRANCH WIRE)


    1. A01IOSCE10
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H71-14 (CA1H) - H71-13 (CA1L) Ignition switch off 54 to 69 Ω
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    B

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    C

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (POWER MANAGEMENT CONTROL ECU)

    A

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

  19. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (CENTER AIRBAG SENSOR ASSEMBLY CAN BRANCH WIRE)


    1. A01IRRWE03
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Center Airbag Sensor Assembly)

      Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.

    2. Disconnect the H19 center airbag sensor assembly connector Click here.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H19-13 (CANH) - H19-22 (CANL) Ignition switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CENTER AIRBAG SENSOR ASSEMBLY)

    OK

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here