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 [branch wire]/CANL [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)*1

  • Brake actuator assembly (ABS ECU)*2

  • Main body ECU (instrument panel junction block assembly)

  • Yaw rate sensor*1

  • Spiral cable sub-assembly (steering angle sensor)*1

  • Power steering ECU assembly

  • Certification ECU*3

  • Air conditioning amplifier assembly*4

  • Center airbag sensor assembly

  • Power management control ECU*3

WIRING DIAGRAM

A01IQ4HE01
A01INJKE02

INSPECTION PROCEDURE

Note

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)


    1. Disconnect the A53*1 brake actuator assembly (ABS ECU) or A52*2 or A54*3 brake actuator assembly (VSC ECU) connector.


      • *1: w/o Vehicle Stability Control System

      • *2: w/ Vehicle Stability Control System (for AD Series Engine)

      • *3: w/ Vehicle Stability Control System (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 CAN BRANCH WIRE)


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

      A01ISIXE03

      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
      w/ Vehicle Stability Control System (for AD Series Engine)
      Tester Connection Switch Condition Specified Condition
      A52-35 (CANH) - A52-14 (CANL) Ignition switch off 54 to 69 Ω
      w/ Vehicle Stability Control System (for ZR Series Engine)
      Tester Connection Switch Condition Specified Condition
      A54-35 (CANH) - A54-14 (CANL) Ignition switch off 54 to 69 Ω
      w/o Vehicle Stability Control System
      Tester Connection Switch Condition Specified Condition
      A53-26 (CANH) - A53-15 (CANL) Ignition switch off 54 to 69 Ω
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Brake Actuator Assembly)

      		 *2 w/ Vehicle Stability Control System (for AD Series Engine)
      *3 w/ Vehicle Stability Control System (for ZR Series Engine) *4 w/o Vehicle Stability Control System
      Result
      Result Proceed to
      OK (w/ Vehicle Stability Control System) A
      OK (w/o Vehicle Stability Control System) B
      NG C

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY (ABS ECU) Click here

    C

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

    A

    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 main wire and the 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)

    Note

    For vehicles without a vehicle stability control system, go to "Check for Open in One Side of Branch Wire (Power Steering ECU)".


    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) 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 main wire and the 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)


    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) Click here

    A

  8. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (SPIRAL CABLE 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 main wire and the 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)

    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)


    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 (AIR CONDITIONING AMPLIFIER) Click here

    A

  10. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (POWER STEERING ECU 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 main wire and the 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 (AIR CONDITIONING AMPLIFIER)

    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 and 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

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


    1. A01IOPRE01
      Text in Illustration
      *1 for Automatic Air Conditioning System
      *2 for Manual Air Conditioning System and 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 main wire and the 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 and 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)

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  13. 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)".


    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

  14. 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 main wire and the 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

  15. 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 OPEN IN ONE SIDE OF CAN BRANCH WIRE (CENTER AIRBAG SENSOR CAN BRANCH WIRE) Click here

    A

  16. 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 main wire and the 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

  17. CHECK OPEN IN ONE SIDE OF CAN BRANCH WIRE (CENTER AIRBAG SENSOR 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 main wire and the 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.

    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)

    OK

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here