CAN COMMUNICATION SYSTEM(for LHD with Central Gateway ECU) Check Bus 2 Lines for Short Circuit

DESCRIPTION

There may be a short circuit between the bus 2 CAN main wires and/or CAN branch wires when the resistance between terminals 18 (CA4H) and 17 (CA4L) of the central gateway ECU is below 54 Ω.

Detection Item Trouble Area
Resistance between terminals 18 (CA4H) and 17 (CA4L) of central gateway ECU is below 54 Ω.

  • Short in bus 2 CAN main wires

  • Short in bus 2 CAN branch wires

  • ECM

  • 4WD control ECU

  • Power steering ECU assembly*1

  • Airbag sensor assembly

  • Tire pressure warning ECU*2

  • Air conditioning amplifier assembly

  • Central gateway ECU

  • Main body ECU (multiplex network body ECU)

  • Master cylinder solenoid (skid control ECU)

  • Headlight leveling ECU assembly

  • Certification ECU (smart key ECU assembly)*3

  • Steering control ECU*4

  • Spiral with sensor cable sub-assembly (steering angle sensor)

  • Combination meter assembly

  • No. 1 CAN junction connector

  • No. 2 CAN junction connector

WIRING DIAGRAM

B001X3HE01
B001WTUE01
B001ZUPE03

CAUTION / NOTICE / HINT

Note


  • Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output Click here.

  • Before measuring the resistance of the CAN bus, turn the ignition switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • 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.

  • After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed Click here.

Tech Tips


  • Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE


  1. CHECK FOR SHORT IN CAN BUS WIRES (ECM - NO. 1 CAN JUNCTION CONNECTOR)


    1. B001YT4E02
      Text in Illustration
      *A for 1UR-FE
      *B for 1VD-FTV
      *C for 3UR-FE
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the cable from the negative (-) battery terminal.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      for 1UR-FE, 1GR-FE:
      Tester Connection Condition Specified Condition
      A38-10 (CANH) - A38-11 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      for 1VD-FTV:
      Tester Connection Condition Specified Condition
      A38-41 (CANH) - A38-49 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      for 3UR-FE:
      Tester Connection Condition Specified Condition
      A38-11 (CANH) - A38-19 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Result Proceed to
      OK (for 1UR-FE) A
      OK (for 1VD-FTV) B
      OK (for 1GR-FE) C
      OK (for 3UR-FE) D
      NG E

    A

    REPLACE ECM Click here

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here

    D

    REPLACE ECM Click here

    E

  2. CONNECT CONNECTOR


    1. Reconnect the A38 ECM connector.


    NEXT

  3. CHECK FOR SHORT IN CAN BUS WIRES (COMBINATION METER ASSEMBLY - NO. 2 CAN JUNCTION CONNECTOR)


    1. B001VKJE01
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Combination Meter Assembly)

      Disconnect the combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E119-39 (CANH) - E119-40 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

    NG

  4. CONNECT CONNECTOR


    1. Reconnect the E119 combination meter assembly connector.


    NEXT

  5. CHECK FOR SHORT IN CAN BUS WIRES (CENTRAL GATEWAY ECU - NO. 1 CAN JUNCTION CONNECTOR)


    1. B001YU8E01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Central Gateway ECU)

      Disconnect the central gateway ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E145-18 (CA4H) - E145-17 (CA4L) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

    OK

    REPLACE CENTRAL GATEWAY ECU Click here

    NG

  6. CONNECT CONNECTOR


    1. Reconnect the E145 central gateway ECU connector.


    NEXT

  7. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 CAN JUNCTION CONNECTOR)


    1. Disconnect the No. 1 CAN junction connector.

      B001Z3DE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to No. 1 CAN Junction Connector)

      		 *b to No. 2 CAN Junction Connector
      *c to 4WD Control ECU *d to Power Steering ECU Assembly (w/ Variable Flow Control Solenoid Valve)
      *e to Airbag Sensor Assembly *f to Tire Pressure Warning ECU (w/ Tire Pressure Warning System)
      *g to ECM *h to Air Conditioning Amplifier Assembly
      *i to Central Gateway ECU - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connect to
      E135-1 (CANH) - E135-11 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 2 CAN junction connector
      E135-2 (CANH) - E135-12 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher 4WD control ECU
      E135-3 (CANH) - E135-13 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Power steering ECU assembly*1
      E135-4 (CANH) - E135-14 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Airbag sensor assembly
      E135-5 (CANH) - E135-15 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Tire pressure warning ECU*2
      E135-7 (CANH) - E135-17 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω ECM
      E135-8 (CANH) - E135-18 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Air conditioning amplifier assembly
      E135-9 (CANH) - E135-19 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Central gateway ECU

      • *1: w/ Variable Flow Control Solenoid Valve

      • *2: w/ Tire Pressure Warning System

      Result
      Result Proceed to
      OK A
      NG (ECM CAN main wire) B
      NG (Central gateway ECU CAN branch wire) C
      NG (No. 2 CAN junction connector CAN main wire) D
      NG (ECU or sensor CAN branch wires) E

    A

    REPLACE NO. 1 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 1 CAN JUNCTION CONNECTOR - ECM)

    C

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (NO. 1 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU)

    E

    CHECK FOR SHORT IN CAN BUS WIRES (ECU, SENSOR) Click here

    D

  8. CONNECT CONNECTOR


    1. Reconnect the E135 No. 1 CAN junction connector.


    NEXT

  9. CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 CAN JUNCTION CONNECTOR)


    1. Disconnect the No. 2 CAN junction connector.

      B001YSAE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to No. 2 CAN Junction Connector)

      		 *b to No. 1 CAN Junction Connector
      *c to Main Body ECU (Multiplex Network Body ECU) *d to Master Cylinder Solenoid (Skid Control ECU)
      *e to Headlight Leveling ECU Assembly *f to Certification ECU (Smart Key ECU Assembly) (w/ Entry and Start System)
      *g to Combination Meter Assembly *h to Steering Control ECU (w/ Variable Gear Ratio Steering System)
      *i to Spiral with Sensor Cable Sub-assembly (Steering Angle Sensor) - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connect to
      E133-1 (CANH) - E133-11 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 1 CAN junction connector
      E133-2 (CANH) - E133-12 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Main body ECU (multiplex network body ECU)
      E133-3 (CANH) - E133-13 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Master cylinder solenoid (skid control ECU)
      E133-4 (CANH) - E133-14 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Headlight leveling ECU assembly
      E133-6 (CANH) - E133-16 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Certification ECU (smart key ECU assembly)*1
      E133-7 (CANH) - E133-17 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Combination meter assembly
      E133-8 (CANH) - E133-18 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Steering control ECU*2
      E133-10 (CANH) - E133-20 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Spiral with sensor cable sub-assembly (steering angle sensor)

      • *1: w/ Entry and Start System

      • *2: w/ Variable Gear Ratio Steering System

      Result
      Result Proceed to
      OK A
      NG (Combination meter assembly CAN main wire) B
      NG (No. 1 CAN junction connector CAN main wire) C
      NG (ECU or sensor CAN branch wires) D

    A

    REPLACE NO. 2 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 2 CAN JUNCTION CONNECTOR - COMBINATION METER ASSEMBLY)

    C

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 2 CAN JUNCTION CONNECTOR - NO. 1 CAN JUNCTION CONNECTOR)

    D

  10. CHECK FOR SHORT IN CAN BUS WIRES (ECU, SENSOR)


    1. B00201LE02
      Text in Illustration
      *a

      Component with harness connected

      (Central Gateway ECU)

      Reconnect the CAN junction connector.

    2. Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the short circuited CAN branch wire is connected.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E145-18 (CA4H) - E145-17 (CA4L) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

      Tech Tips

      If the resistance becomes normal (between 54 and 69 Ω) when the connector is disconnected from the ECU or sensor, there may be a short in the ECU or sensor.


    OK

    REPLACE CORRESPONDING ECU OR SENSOR

    NG

    REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR CAN BRANCH WIRES OR CONNECTOR