CAN COMMUNICATION SYSTEM(for LHD without Central Gateway ECU) Short in CAN Bus Lines

DESCRIPTION

There may be a short circuit between the CAN bus lines when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is below 53 Ω.

Detection Item Trouble Area
The resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is below 53 Ω.

  • Short between CAN bus lines

  • 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)

  • Multi-media module receiver assembly*5

  • Radio and display receiver assembly*6

  • Combination meter assembly

  • DLC3 CAN branch wire or connector

  • No. 1 CAN junction connector

  • No. 2 CAN junction connector

WIRING DIAGRAM

B001ZUIE01
B001Y23E01
B00207FE02

CAUTION / NOTICE / HINT

Note


  • 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.

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 (NO. 1 CAN JUNCTION CONNECTOR)


    1. Disconnect the No. 1 CAN junction connector.

      B001YXKE01
      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 Bus Buffer ECU (w/ Bus Buffer ECU) *h to ECM
      *i to Air Conditioning Amplifier Assembly - -

    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
      E135-6 (CANH) - E135-16 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Bus buffer ECU*3
      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

      • *1: w/ Variable Flow Control Solenoid Valve

      • *2: w/ Tire Pressure Warning System

      • *3: w/ Bus Buffer ECU

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

    A

    REPLACE NO. 1 CAN JUNCTION CONNECTOR

    B

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

    D

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

    C

  6. CONNECT CONNECTOR


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


    NEXT

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


    1. Disconnect the No. 2 CAN junction connector.

      B001YZ2E01
      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 Multi-media Module Receiver Assembly (for Multimedia Module Receiver Type)

      • to Radio and Display Receiver Assembly (for Radio and Display Type)
      *g to Certification ECU (Smart Key ECU Assembly) (w/ Entry and Start System) *h to Combination Meter Assembly
      *i

      to Spiral with Sensor Cable Sub-assembly (Steering Angle Sensor)

      to Steering Control ECU (w/ Variable Gear Ratio Steering System)

      		 *j to DLC3
      *k to Steering Control ECU (w/ Variable Gear Ratio Steering System)

    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
      E133-5 (CANH) - E133-15 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      • Multi-media module receiver assembly*1

      • Radio and display receiver assembly*2
      E133-6 (CANH) - E133-16 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Certification ECU (smart key ECU assembly)*3
      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*4
      E133-9 (CANH) - E133-19 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher DLC3
      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: for Multi-media Module Receiver Type

      • *2: for Radio and Display Type

      • *3: w/ Entry and Start System

      • *4: 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 (DLC3 CAN branch wires) D
      NG (ECU or sensor CAN branch wires) E

    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

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DLC3 (CANH, CANL)

    E

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


    1. B001WYWE01
      Text in Illustration
      *a Front view of DLC3

      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
      E22-6 (CANH) - E22-14 (CANL) 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