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 [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.

  • Skid control ECU assembly

  • Main body ECU (driver side junction block)

  • No. 1 meter ECU sub-assembly

  • Multi-media module receiver assembly

  • Air conditioning amplifier assembly

  • Headlight swivel ECU assembly

WIRING DIAGRAM

A01GYU9E02
A01GW34E02

INSPECTION PROCEDURE

Note


  • 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.

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the auxiliary battery terminal notice before proceeding with work 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 ECM or center airbag sensor assembly as they are the end parts of the circuit. If removed, CAN communication will not be possible.

  • The open circuit confirmation of the ECM, center airbag sensor assembly and CAN main wire is performed in the CAN V bus line check 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 CAN BRANCH WIRE (SKID CONTROL ECU ASSEMBLY)


    1. Disconnect the A21 skid control ECU assembly connector.

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

      Result
      Result Proceed to
      "Skid Control (ABS/VSC/TRAC)" is not displayed on the intelligent tester A
      "Skid Control (ABS/VSC/TRAC)" is 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 (SKID CONTROL ECU ASSEMBLY CAN BRANCH WIRE)


    1. A01GWOSE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU Assembly)

      Disconnect the cable from the negative (-) auxiliary 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 (-) auxiliary 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
      A21-9 (CANH) - A21-8 (CANL) Power switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (SKID CONTROL ECU ASSEMBLY)

    OK

    REPLACE SKID CONTROL ECU ASSEMBLY Click here

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


    1. Disconnect the L11 main body ECU (driver side junction block) connector.

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

      Result
      Result Proceed to
      "Main Body" is not displayed on the intelligent tester A
      "Main Body" is not displayed on the intelligent tester B

    B

    CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (NO. 1 METER ECU SUB-ASSEMBLY) Click here

    A

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


    1. A01GXSAE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Main Body ECU [Driver Side Junction Block])

      Disconnect the cable from the negative (-) auxiliary 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 (-) auxiliary 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
      L11-5 (CANH) - L11-6 (CANL) Power switch off 54 to 69 Ω

    NG

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

    OK

    REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK)

  5. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (NO. 1 METER ECU SUB-ASSEMBLY)


    1. Disconnect the L124 No. 1 meter ECU sub-assembly connector.

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

      Result
      Result Proceed to
      "Combination Meter" is not displayed on the intelligent tester A
      "Combination Meter" is not displayed on the intelligent tester B

    B

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

    A

  6. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (NO. 1 METER ECU SUB-ASSEMBLY CAN BRANCH WIRE)


    1. A01H1Q1E04
      Text in Illustration
      *a

      Front view of wire harness connector

      (to No. 1 Meter ECU Sub-assembly)

      Disconnect the cable from the negative (-) auxiliary 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 (-) auxiliary 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
      L124-20 (CANH) - L124-21 (CANL) Power switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (NO. 1 METER ECU SUB-ASSEMBLY)

    OK

    REPLACE NO. 1 METER ECU SUB-ASSEMBLY Click here

  7. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (HEADLIGHT SWIVEL ECU ASSEMBLY)


    1. Disconnect the A37 headlight swivel ECU assembly connector.

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

      Result
      Result Proceed to
      "Headlight swivel (AFS)" is not displayed on the intelligent tester A
      "Headlight swivel (AFS)" is not displayed on the intelligent tester B

    B

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

    A

  8. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (HEADLIGHT SWIVEL ECU ASSEMBLY CAN BRANCH WIRE)


    1. A01H10VE07
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Headlight Swivel ECU Assembly)

      Disconnect the cable from the negative (-) auxiliary 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 (-) auxiliary 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
      A37-12 (CANH) - A37-13 (CANL) Power switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (HEADLIGHT SWIVEL ECU ASSEMBLY)

    OK

    REPLACE HEADLIGHT SWIVEL ECU ASSEMBLY Click here

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


    1. Disconnect the L164 multi-media module receiver assembly connector.

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

      Result
      Result Proceed to
      "Display and Navigation (AVN1)" is not displayed on the intelligent tester A
      "Display and Navigation (AVN1)" is not displayed on the intelligent tester B

    B

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

    A

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


    1. A01GXIOE44
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Multi-media Module Receiver Assembly)

      Disconnect the cable from the negative (-) auxiliary 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 (-) auxiliary 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
      L164-1 (CANH) - L164-2 (CANL) Power 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

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


    1. A01GYDAE01
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Air Conditioning Amplifier Assembly)

      Disconnect the cable from the negative (-) auxiliary 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 (-) auxiliary 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 air conditioning amplifier assembly connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      L77-3 (CANH) - L77-4 (CANL) Power 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