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*1

  • Headlight swivel ECU assembly*2

  • Multi-media module receiver assembly*3

  • Air conditioning amplifier assembly

  • Main body ECU (cowl side junction block LH)

  • Network gateway ECU*4

  • 4WD control ECU*5

  • Clearance warning ECU assembly*5, *6

  • Master cylinder solenoid (skid control ECU)*5

WIRING DIAGRAM

B001ZWHE01
B001W0KE01
w/ Network Gateway ECU
*a Main Body ECU (Cowl Side Junction Block LH)
*b No. 3 Junction Connector
*c Combination Meter Assembly
B001VLQE01
B002074E01
w/o Network Gateway ECU
*a Master Cylinder Solenoid (Skid Control ECU)
*b Main Body ECU (Cowl Side Junction Block LH)
*c No. 3 Junction Connector
*d Combination Meter Assembly

CAUTION / NOTICE / HINT

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 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 CAN BRANCH WIRE (MULTI-MEDIA MODULE RECEIVER ASSEMBLY)

    Note

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


    1. Disconnect the F77 multi-media module receiver assembly connector.

    2. Select "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 CAN BRANCH WIRE (CENTER AIRBAG SENSOR ASSEMBLY) Click here

    A

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


    1. A01X50TE01
      Text in Illustration
      *a

      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:

      For vehicles with an SRS system:

      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
      F77-1 (CANH) - F77-2 (CANL) Ignition switch off 54 to 69 Ω

    OK

    REPLACE MULTI-MEDIA MODULE RECEIVER ASSEMBLY Click here

    NG

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

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

    Note

    For vehicles without an airbag system, go to "Check for Open in One Side of CAN Branch Wire (Air Conditioning Amplifier Assembly)".


    1. Disconnect the E47 center airbag sensor assembly connector.

    2. Select "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 CAN BRANCH WIRE (AIR CONDITIONING AMPLIFIER ASSEMBLY) Click here

    A

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


    1. A01WZGEE02
      Text in Illustration
      *a

      Rear 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) Ignition switch off 54 to 69 Ω

    OK

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here

    NG

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

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


    1. Disconnect the E35*1 or E81*2 air conditioning amplifier assembly connector.

      *1: w/ Rear Air Conditioning System

      *2: w/o Rear Air Conditioning System

    2. Select "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 CAN BRANCH WIRE (HEADLIGHT SWIVEL ECU ASSEMBLY) Click here

    A

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


    1. A01X4N9E01
      Text in Illustration
      *A w/ Rear Air Conditioning System
      *B w/o Rear Air Conditioning System
      *a

      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:

      For vehicles with an SRS system:

      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/ Rear Air Conditioning System
      Tester Connection Switch Condition Specified Condition
      E35-3 (CANH) - E35-4 (CANL) Ignition switch off 54 to 69 Ω
      w/o Rear Air Conditioning System
      Tester Connection Switch Condition Specified Condition
      E81-11 (CANH) - E81-12 (CANL) Ignition switch off 54 to 69 Ω

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

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

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

    Note

    For vehicles without dynamic headlight auto leveling, go to "Check for Open in One Side of CAN Branch Wire (Main Body ECU)".


    1. Disconnect the E101 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
      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 CAN BRANCH WIRE (MAIN BODY ECU) Click here

    A

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


    1. A01X02NE01
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Headlight Swivel 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:

      For vehicles with an SRS system:

      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
      E101-12 (MPX1) - E101-13 (MPX2) Ignition switch off 54 to 69 Ω

    OK

    REPLACE HEADLIGHT SWIVEL ECU ASSEMBLY Click here

    NG

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

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


    1. Disconnect the E3 main body ECU (cowl side junction block LH) 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
      Several ECUs and sensors in addition to "Main Body" are displayed on the intelligent tester B

    B

    SYSTEM CHECK Click here

    A

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


    1. A01XB1QE01
      Text in Illustration
      *a

      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:

      For vehicles with an SRS system:

      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) Ignition switch off 54 to 69 Ω

    OK

    REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)

    NG

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

  11. SYSTEM CHECK


    1. Check the vehicle specifications.

      Result
      Result Proceed to
      w/ Network Gateway ECU A
      w/o Network Gateway ECU B

    B

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

    A

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


    1. A01X2MOE01
      Text in Illustration
      *a

      Rear 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:

      For vehicles with an SRS system:

      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) Ignition switch off 54 to 69 Ω

    OK

    REPLACE NETWORK GATEWAY ECU Click here

    NG

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

  13. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (CLEARANCE WARNING ECU ASSEMBLY)

    Note

    For vehicles without an TOYOTA parking assist-sensor system, go to "Check for Open in One Side of CAN Branch Wire (4WD Control ECU)".


    1. Disconnect the F12 clearance warning ECU assembly connector.

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

      Result
      Result Proceed to
      "Clearance Warning (Clearance Sonar)" is not displayed on the intelligent tester A
      Several ECUs and sensors in addition to "Clearance Warning (Clearance Sonar)" are displayed on the intelligent tester B

    B

    CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (4WD CONTROL ECU) Click here

    A

  14. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (CLEARANCE WARNING ECU ASSEMBLY CAN BRANCH WIRE)


    1. A01X05TE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Clearance Warning 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:

      For vehicles with an SRS system:

      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
      F12-3 (CANH) - F12-5 (CANL) Ignition switch off 54 to 69 Ω

    OK

    REPLACE CLEARANCE WARNING ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CLEARANCE WARNING ECU ASSEMBLY)

  15. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (4WD CONTROL ECU)


    1. Disconnect the A27 4WD control ECU connector.

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

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

    B

    CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (SKID CONTROL ECU) Click here

    A

  16. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (4WD CONTROL ECU CAN BRANCH WIRE)


    1. A01XBQDE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to 4WD 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:

      For vehicles with an SRS system:

      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
      A27-19 (CAN+) - A27-20 (CAN-) Ignition switch off 54 to 69 Ω

    OK

    REPLACE 4WD CONTROL ECU Click here

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (4WD CONTROL ECU)

  17. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (SKID CONTROL ECU)


    1. A01XA9OE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Master Cylinder Solenoid [Skid 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:

      For vehicles with an SRS system:

      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 A24 master cylinder solenoid (skid control ECU) connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A24-11 (CANH) - A24-25 (CANL) Ignition switch off 54 to 69 Ω

    OK

    REPLACE MASTER CYLINDER SOLENOID (SKID CONTROL ECU) Click here

    NG

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