CAN COMMUNICATION SYSTEM(w/o Central Gateway ECU) Check CAN Bus Line for Short to GND (RHD Models)

DESCRIPTION

There may be a short circuit between one of the CAN bus lines and GND when there is no resistance between terminals 6 (CANH) and 4 (CG) or 14 (CANL) and 4 (CG) of the DLC3.

Symptom Trouble Area
No resistance exists between terminals 6 (CANH) and 4 (CG) or 14 (CANL) and 4 (CG) of DLC3.

  • Short to ground in CAN main bus line

  • Short to ground in CAN branch line

  • Power management control ECU

  • ECM

  • Main body ECU (Multiplex network body ECU)

  • Meter circuit plate

  • Brake booster with master cylinder assembly (Skid control ECU)

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

  • Yaw rate sensor

  • Power steering ECU assembly

  • Airbag ECU assembly

  • Transmission control ECU assembly

  • Certification ECU (Smart key ECU assembly)

  • Navigation ECU sub-assembly*1

  • Radio and display receiver assembly*2

  • CAN No. 1 junction connector

  • CAN No. 2 junction connector

  • CAN No. 3 junction connector

*1: for Navigation receiver type

*2: for Radio and display type

WIRING DIAGRAM

A005CYPE03
A005E8GE08

CAUTION / NOTICE / HINT

Note


  • Before measuring the resistance of the CAN bus, turn the power 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 (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work Click here.

  • 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.

  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

  • DTC check procedure: Turn the power switch on (IG), turn the cruise control system on using the cruise control switch (ON/OFF switch), wait at least 60 seconds, and then drive the vehicle at a speed of 50 km/h (31 mph) or more for at least 1.72 seconds.

  • 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 power switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.

  • 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 LINE (CAN NO. 2 J/C)


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

    2. A005BYDE02
      Text in Illustration
      *1 DLC3
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *b to CAN No. 1 Junction Connector
      *c to CAN No. 3 Junction Connector
      *d to Certification ECU (Smart Key ECU Assembly)
      *e to Spiral Cable with Sensor Sub-assembly (Steering Angle Sensor)

      Disconnect the wire harness connector from the CAN No. 2 junction connector (instrument panel connector holder left side).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      L94-1 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher CAN No. 1 junction connector
      L94-2 (CANL) - L61-4 (CG)
      L94-4 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher CAN No. 3 junction connector
      L94-5 (CANL) - L61-4 (CG)
      L94-7 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Certification ECU (Smart key ECU assembly)
      L94-8 (CANL) - L61-4 (CG)
      L94-10 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Spiral cable with sensor sub-assembly (Steering angle sensor)
      L94-11 (CANL) - L61-4 (CG)
      Result
      Result Proceed to
      OK A
      NG (CAN No. 1 junction connector main line) B
      NG (CAN No. 3 junction connector main line) C
      NG (ECU or sensor bus line) D

    B

    CHECK FOR SHORT TO GND IN CAN BUS LINE (CAN NO. 1 J/C) Click here

    C

    CHECK SHORT TO GND IN CAN BUS LINE (CAN NO. 3 J/C) Click here

    D

    CHECK FOR SHORT TO GND IN CONNECTED COMPONENT (ECU, SENSOR) Click here

    A

  2. CHECK FOR SHORT TO GND IN CAN BUS LINE (CAN NO. 2 J/C)


    1. A005AEME02
      Text in Illustration
      *1 DLC3
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *b to Power Steering ECU Assembly
      *c to Yaw Rate Sensor
      *d to Airbag ECU Assembly
      *e

      • to Navigation ECU Sub-assembly*1

      • to Radio and Display Receiver Assembly*2
      *f to DLC3

      Disconnect the wire harness connector from the CAN No. 2 junction connector (instrument panel connector holder right side).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      L95-3 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Power steering ECU assembly
      L95-2 (CANL) - L61-4 (CG)
      L95-6 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Yaw rate sensor
      L95-5 (CANL) - L61-4 (CG)
      L95-9 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Airbag ECU assembly
      L95-8 (CANL) - L61-4 (CG)
      L95-12 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher

      • Navigation ECU sub-assembly*1

      • Radio and display receiver assembly*2
      L95-11 (CANL) - L61-4 (CG)
      L95-15 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher DLC3
      L95-14 (CANL) - L61-4 (CG)

      *1: for Navigation receiver type

      *2: for Radio and display type

      *1: for Navigation receiver type

      *2: for Radio and display type

      Result
      Result Proceed to
      OK A
      NG (ECU or sensor bus line) B
      NG (DLC3 branch line) C

    A

    REPLACE CAN NO. 2 JUNCTION CONNECTOR

    B

    CHECK FOR SHORT TO GND IN CONNECTED COMPONENT (ECU, SENSOR) Click here

    C

    REPAIR OR REPLACE CAN BRANCH LINE CONNECTED TO DLC3

  3. CHECK FOR SHORT TO GND IN CAN BUS LINE (CAN NO. 1 J/C)


    1. A005EHJE03
      Text in Illustration
      *1 DLC3
      *a

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *b to CAN No. 2 Junction Connector
      *c to Meter Circuit Plate

      Disconnect the wire harness connector from the CAN No. 1 junction connector (instrument panel wire side).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      L132-5 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher CAN No. 2 junction connector
      L132-11 (CANL) - L61-4 (CG)
      L132-6 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Meter circuit plate
      L132-12 (CANL) - L61-4 (CG)
      Result
      Result Proceed to
      OK A
      NG (CAN No. 2 junction connector main line) B
      NG (Meter circuit plate main line) C

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 1 J/C - CAN NO. 2 J/C)

    C

    CHECK FOR SHORT TO GND IN CONNECTED COMPONENT (ECU, SENSOR) Click here

    A

  4. CHECK SHORT TO GND IN CAN BUS LINE (CAN NO. 1 J/C)


    1. A005BODE02
      Text in Illustration
      *1 DLC3
      *a

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *b to Brake Booster with Master Cylinder Assembly (Skid Control ECU)

      Disconnect the wire harness connector from the CAN No. 1 junction connector (engine room main wire side).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      A67-1 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Brake booster with master cylinder assembly (Skid control ECU)
      A67-7 (CANL) - L61-4 (CG)
      Result
      Result Proceed to
      OK A
      NG (ECU or sensor bus line) B

    A

    REPLACE CAN NO. 1 JUNCTION CONNECTOR

    B

    CHECK FOR SHORT TO GND IN CONNECTED COMPONENT (ECU, SENSOR) Click here

  5. CHECK SHORT TO GND IN CAN BUS LINE (CAN NO. 3 J/C)


    1. A005AR4E02
      Text in Illustration
      *1 DLC3
      *a

      Front view of wire harness connector

      (to CAN No. 3 Junction Connector)
      *b to Power Management Control ECU
      *c to Main Body ECU (Multiplex Network Body ECU)
      *d to CAN No. 2 Junction Connector

      Disconnect the wire harness connector from the CAN No. 3 junction connector (instrument panel wire side).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      L133-4 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Power management control ECU
      L133-10 (CANL) - L61-4 (CG)
      L133-5 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Main body ECU (multiplex network body ECU)
      L133-11 (CANL) - L61-4 (CG)
      L133-6 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher CAN No. 2 junction connector
      L133-12 (CANL) - L61-4 (CG)
      Result
      Result Proceed to
      OK A
      NG (CAN No. 2 junction connector main line) B
      NG (ECU or sensor bus line) C

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 2 J/C - CAN NO. 3 J/C)

    C

    CHECK FOR SHORT TO GND IN CONNECTED COMPONENT (ECU, SENSOR) Click here

    A

  6. CHECK SHORT TO GND IN CAN BUS LINE (CAN NO. 3 J/C)


    1. A005CS7E02
      Text in Illustration
      *1 DLC3
      *a

      Front view of wire harness connector

      (to CAN No. 3 Junction Connector)
      *b to ECM
      *c to Transmission Control ECU Assembly

      Disconnect the wire harness connector from the CAN No. 3 junction connector (engine room main wire side).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      A68-1 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher ECM
      A68-7 (CANL) - L61-4 (CG)
      A68-2 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Transmission control ECU assembly
      A68-8 (CANL) - L61-4 (CG)
      Result
      Result Proceed to
      OK A
      NG (ECU or sensor bus line) B

    A

    REPLACE CAN NO. 3 JUNCTION CONNECTOR

    B

  7. CHECK FOR SHORT TO GND IN CONNECTED COMPONENT (ECU, SENSOR)


    1. Reconnect all wire harness connectors (CAN No. 1 junction connector, CAN No. 2 junction connector and CAN No. 3 junction connector).

    2. Disconnect the ECU or sensor connected to the CAN bus line that is shorted to ground.

      Tech Tips

      If the ECU or sensor has multiple connectors, disconnect the connector that includes the CAN bus lines. To determine the ECU or sensor that is connected to the shorted bus line, refer to the terminals of ECU tables Click here.

    3. A005CJDE03
      Text in Illustration
      *1 DLC3

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L61-6 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      L61-14 (CANL) - L61-4 (CG)

      Tech Tips

      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).


    OK

    REPLACE CORRESPONDING ECU OR SENSOR

    NG

    REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR BUS LINE OR CONNECTOR