CAN COMMUNICATION SYSTEM (for LHD) 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.

  • One side of CAN branch wire is open

  • Center airbag sensor assembly

  • Multi-media module receiver assembly

  • Air conditioning amplifier assembly

  • Main body ECU (cowl side junction block LH)

  • Headlight swivel ECU assembly (AFS ECU)

  • Network gateway ECU

WIRING DIAGRAM

A01ERKGE01
A01EMU6E04

INSPECTION PROCEDURE

Note


  • After turning the engine 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.

  • The vehicle is equipped with an SRS (Supplemental Restraint System) which includes components such as airbags. Before servicing (including removal or installation of parts), be sure to read the Precaution in the SRS Click here.

Tech Tips


  • Perform the following inspection for the ECUs (sensors) which are 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 CAN 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 a CAN branch wire.

PROCEDURE


  1. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (MULTI-MEDIA MODULE RECEIVER ASSEMBLY)


    1. Disconnect the F76 multi-media module receiver assembly connector.

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

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

    B

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

    A

  2. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (MULTI-MEDIA MODULE RECEIVER ASSEMBLY CAN BRANCH WIRE)


    1. A01EQL4E23
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Multi-media Module 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
      F76-1 (CANH) - F76-2 (CANL) Engine switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (MULTI-MEDIA MODULE RECEIVER ASSEMBLY)

    OK

    REPLACE MULTI-MEDIA MODULE RECEIVER ASSEMBLY Click here

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


    1. Disconnect the E47 center airbag sensor assembly connector Click here.

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

      Result
      Result Proceed to
      "Airbag" is not displayed on the intelligent tester A
      Several ECUs and sensors in addition to "Airbag" are displayed on the intelligent tester B

    B

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

    A

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


    1. A01EQRKE01
      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. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      E47-13 (CANH) - E47-22 (CANL) Engine 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

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


    1. Disconnect the E35 air conditioning amplifier assembly connector.

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

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

    B

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

    A

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


    1. A01EQHRE01
      Text in Illustration
      *1

      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
      Tester Connection Switch Condition Specified Condition
      E35-3 (CANH) - E35-4 (CANL) Engine 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

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


    1. Disconnect the E3 main body ECU (cowl side junction block LH) connector.

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

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

    B

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

    A

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


    1. A01EPRFE03
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to Main Body ECU [Cowl Side Junction Block LH])

      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
      E3-5 (CANH) - E3-6 (CANL) Engine switch off 54 to 69 Ω

    NG

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

    OK

    REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)

  9. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (AFS ECU)


    1. Disconnect the E91 headlight swivel ECU assembly (AFS ECU) connector.

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

      Result
      Result Proceed to
      "Headlight swivel (AFS)" is not displayed on the intelligent tester A
      Several ECUs and sensors in addition to "Headlight swivel (AFS)" are displayed on the intelligent tester B

    B

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

    A

  10. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (AFS ECU CAN BRANCH WIRE)


    1. A01EOXNE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Headlight Swivel ECU Assembly [AFS 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
      E91-12 (MPX1) - E91-13 (MPX2) Engine switch off 54 to 69 Ω

    NG

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

    OK

    REPLACE HEADLIGHT SWIVEL ECU ASSEMBLY (AFS ECU) Click here

  11. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (NETWORK GATEWAY ECU CAN BRANCH WIRE)


    1. A01EQI5E01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Network Gateway 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. Disconnect the E31 network gateway ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      E31-16 (CA1H) - E31-15 (CA1L) Engine switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (NETWORK GATEWAY ECU)

    OK

    REPLACE NETWORK GATEWAY ECU Click here