CAN COMMUNICATION SYSTEM Check Bus 2 Line for Short to GND

DTC Code DTC Name
Check Bus 2 Line for Short to GND

DESCRIPTION

There may be a short circuit between one of the CAN bus wires and GND when no resistance exists between terminal 18 (CA4H) of the network gateway ECU and terminal 4 (CG) of the DLC3, or terminal 17 (CA4L) of the network gateway ECU and terminal 4 (CG) of the DLC3.

Detection Item

Trouble Area

No resistance exists between terminal 18 (CA4H) of the network gateway ECU and terminal 4 (CG) of the DLC3, or terminal 17 (CA4L) of the network gateway ECU and terminal 4 (CG) of the DLC3.

  • Short to GND in bus 2 CAN main wires

  • Short to GND in bus 2 CAN branch wires

  • Network gateway ECU

  • ECM

  • Brake actuator assembly (skid control ECU)

  • Main body ECU (instrument panel junction block assembly)

  • Pre-collision city sensor*1

  • Certification ECU (smart key ECU assembly)*2

  • Power management control ECU*2

  • Power steering ECU assembly

  • Yaw rate sensor

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

  • Airbag sensor assembly

  • Engine stop and start ECU*3

  • Air conditioning amplifier assembly*4, *5

  • Combination meter assembly

  • No. 1 CAN junction connector

  • No. 2 CAN junction connector

  • No. 3 CAN junction connector

  • *1: w/ Pre-collision System

  • *2: w/ Entry and Start System

  • *3: w/ Stop and Start System

  • *4: for 1ZR-FAE, 2ZR-FAE (w/ Entry and Start System)

  • *5: w/o Entry and Start System

WIRING DIAGRAM

C348020E03
C348021E02
C348022E02
C348020E04
C348023E02
C348024E02

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).

Tip:

  • 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 TO GND IN CAN BUS WIRE (NO. 1 CAN JUNCTION CONNECTOR)

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

      U184753E02
      Table 1. Text in Illustration

      *a

      Rear view of wire harness connector

      (to No. 1 CAN Junction Connector)

      *b

      Front view of DLC3

      *c

      to Main Body ECU (Instrument Panel Junction Block Assembly)

      *d

      to Brake Actuator Assembly (Skid Control ECU)

      *e

      to No. 2 CAN Junction Connector

      *f

      to ECM

    2. Disconnect the No. 1 CAN junction connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      Connect to

      A50-7 (CANH) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      Main body ECU (instrument panel junction block assembly)

      A50-18 (CANL) - H16-4 (CG)

      A50-8 (CANH) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      Brake actuator assembly (skid control ECU)

      A50-19 (CANL) - H16-4 (CG)

      A50-9 (CANH) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      No. 2 CAN junction connector

      A50-20 (CANL) - H16-4 (CG)

      A50-10 (CANH) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      ECM

      A50-21 (CANL) - H16-4 (CG)
      Table 2. Result

      Result

      Proceed to

      OK

      A

      NG (No. 2 CAN junction connector CAN main wire)

      B

      NG (ECU or sensor CAN wires)

      C

    REPLACE NO. 1 CAN JUNCTION CONNECTOR

    CHECK FOR SHORT TO GND IN CAN BUS WIRE (ECU, SENSOR)Click here

  2. CONNECT CONNECTOR

    1. Reconnect the A50 No. 1 CAN junction connector.

  3. CHECK FOR SHORT TO GND IN CAN BUS WIRE (NO. 2 CAN JUNCTION CONNECTOR)

    1. Disconnect the No. 2 CAN junction connector.

      U184722E02
      Table 3. Text in Illustration

      *a

      Front view of wire harness connector

      (to No. 2 CAN Junction Connector)

      *b

      Front view of DLC3

      *c

      to Pre-collision City Sensor (w/ Pre-collision System)

      *d

      to No. 3 CAN Junction Connector

      *e

      to No. 1 CAN Junction Connector

      -

      -

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      Connect to

      Q13-1 (CANH) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      Pre-collision city sensor*

      Q13-7 (CANL) - H16-4 (CG)

      Q13-2 (CANH) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      No. 3 CAN junction connector

      Q13-8 (CANL) - H16-4 (CG)

      Q13-3 (CANH) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      No. 1 CAN junction connector

      Q13-9 (CANL) - H16-4 (CG)

      • *: w/ Pre-collision System

      Table 4. Result

      Result

      Proceed to

      OK

      A

      NG (No. 1 CAN junction connector CAN main wire)

      B

      NG (No. 3 CAN junction connector CAN main wire)

      C

      NG (ECU or sensor CAN branch wires)

      D

    REPLACE NO. 2 CAN JUNCTION CONNECTOR

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

    CHECK FOR SHORT TO GND IN CAN BUS WIRE (ECU, SENSOR)Click here

  4. CONNECT CONNECTOR

    1. Reconnect the Q13 No. 2 CAN junction connector.

  5. CHECK FOR SHORT TO GND IN CAN BUS WIRE (NO. 3 CAN JUNCTION CONNECTOR)

    1. w/ Entry and Start System:

      1. Disconnect the No. 3 CAN junction connector.

        U184754E02
        Table 5. Text in Illustration

        *a

        Rear view of wire harness connector

        (to No. 3 CAN Junction Connector)

        *b

        Front view of DLC3

        *c

        to Power Management Control ECU

        *d

        to Certification ECU (Smart Key ECU Assembly)

        *e

        to Power Steering ECU Assembly

        *f

        to No. 2 CAN Junction Connector

        *g

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

        *h

        to Yaw Rate Sensor

        *i

        to Network Gateway ECU

        *j

        • to Engine Stop and Start ECU (w/ Stop and Start System)

        • to Air Conditioning Amplifier Assembly (for 1ZR-FAE, 2ZR-FAE)

        *k

        to Combination Meter Assembly

        *l

        to Airbag Sensor Assembly

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

        Standard Resistance

        Tester Connection

        Condition

        Specified Condition

        Connect to

        H88-1 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        Power management control ECU

        H88-12 (CANL) - H16-4 (CG)

        H88-2 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        Certification ECU (smart key ECU assembly)

        H88-13 (CANL) - H16-4 (CG)

        H88-3 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        Power steering ECU assembly

        H88-14 (CANL) - H16-4 (CG)

        H88-4 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        No. 2 CAN junction connector

        H88-15 (CANL) - H16-4 (CG)

        H88-5 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

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

        H88-16 (CANL) - H16-4 (CG)

        H88-6 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        Yaw rate sensor

        H88-17 (CANL) - H16-4 (CG)

        H88-7 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        Network gateway ECU

        H88-18 (CANL) - H16-4 (CG)

        H88-8 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        • Engine stop and start ECU*1

        • Air conditioning amplifier assembly*2

        H88-19 (CANL) - H16-4 (CG)

        H88-9 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        Combination meter assembly

        H88-20 (CANL) - H16-4 (CG)

        H88-11 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        Airbag sensor assembly

        H88-22 (CANL) - H16-4 (CG)

        • *1: w/ Stop and Start System

        • *2: for 1ZR-FAE, 2ZR-FAE

    2. w/o Entry and Start System:

      1. Disconnect the No. 3 CAN junction connector.

        U184755E02
        Table 6. Text in Illustration

        *a

        Rear view of wire harness connector

        (to No. 3 CAN Junction Connector)

        *b

        Front view of DLC3

        *c

        to Air Conditioning Amplifier Assembly

        *d

        to Power Steering ECU Assembly

        *e

        to No. 2 CAN Junction Connector

        *f

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

        *g

        to Yaw Rate Sensor

        *h

        to Network Gateway ECU

        *i

        to Engine Stop and Start ECU (w/ Stop and Start System)

        *j

        to Combination Meter Assembly

        *k

        to Airbag Sensor Assembly

        -

        -

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

        Standard Resistance

        Tester Connection

        Condition

        Specified Condition

        Connect to

        H88-2 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        Air conditioning amplifier assembly

        H88-13 (CANL) - H16-4 (CG)

        H88-3 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        Power steering ECU assembly

        H88-14 (CANL) - H16-4 (CG)

        H88-4 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        No. 2 CAN junction connector

        H88-15 (CANL) - H16-4 (CG)

        H88-5 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

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

        H88-16 (CANL) - H16-4 (CG)

        H88-6 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        Yaw rate sensor

        H88-17 (CANL) - H16-4 (CG)

        H88-7 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        Network gateway ECU

        H88-18 (CANL) - H16-4 (CG)

        H88-8 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        Engine stop and start ECU*

        H88-19 (CANL) - H16-4 (CG)

        H88-9 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        Combination meter assembly

        H88-20 (CANL) - H16-4 (CG)

        H88-11 (CANH) - H16-4 (CG)

        Cable disconnected from negative (-) battery terminal

        200 Ω or higher

        Airbag sensor assembly

        H88-22 (CANL) - H16-4 (CG)

        • *: w/ Stop and Start System

        Table 7. Result

        Result

        Proceed to

        OK

        A

        NG (No. 2 CAN junction connector CAN main wire)

        B

        NG (Network gateway ECU CAN branch wire)

        C

        NG (ECU or sensor CAN wires)

        D

    REPLACE NO. 3 CAN JUNCTION CONNECTOR

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 3 CAN JUNCTION CONNECTOR - NO. 2 CAN JUNCTION CONNECTOR)

    CHECK FOR SHORT TO GND IN CAN BUS WIRE (ECU, SENSOR)Click here

  6. CONNECT CONNECTOR

    1. Reconnect the H88 No. 3 CAN junction connector.

  7. CHECK FOR SHORT TO GND IN CAN BUS WIRE (NETWORK GATEWAY ECU - NO. 3 CAN JUNCTION CONNECTOR)

    1. U184738E02

      Disconnect the network gateway ECU connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H131-18 (CA4H) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      H131- 17 (CA4L) - H16-4 (CG)
      Table 8. Text in Illustration

      *a

      Front view of wire harness connector

      (to Network Gateway ECU)

      *b

      Front view of DLC3
      Table 9. Result

      Result

      Proceed to

      OK (for LHD)

      A

      OK (for RHD)

      B

      NG

      C

    REPLACE NETWORK GATEWAY ECU

    (Click here)

    REPLACE NETWORK GATEWAY ECU

    (Click here)

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (NETWORK GATEWAY ECU - NO. 3 CAN JUNCTION CONNECTOR)

  8. CHECK FOR SHORT TO GND IN CAN BUS WIRE (ECU, SENSOR)

    1. U184733E02

      Reconnect the CAN junction connector.

    2. Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the bus line shorted to GND is connected.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H131-18 (CA4H) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      H131-17 (CA4L) - H16-4 (CG)
      Table 10. Text in Illustration

      *a

      Component with harness connected

      (Network Gateway ECU)

      *b

      Front view of DLC3
    Tip:

    If the resistance changes to 200 Ω or higher when the connector is disconnected from the ECU or sensor, there may be a short in the ECU or sensor.

    REPLACE CORRESPONDING ECU OR SENSOR

    REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR CAN WIRES OR CONNECTOR