CAN COMMUNICATION SYSTEM Check Bus 3 Line for Short to +B

DESCRIPTION

There may be a short circuit between one of the CAN bus lines and +B when there is no resistance between terminal 6 (CA3H) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3, or terminal 21 (CA3L) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3.

Symptom Trouble Area
There is no resistance between terminal 6 (CA3H) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3, or terminal 21 (CA3L) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3.

  • Short to +B in CAN main bus wire

  • Short to +B in CAN branch wire

  • Central gateway ECU (network gateway ECU)

  • Radio receiver assembly

  • Telematics transceiver*1

  • Bus buffer ECU*2

  • Luggage closer motor assembly

  • Rear multiplex network door ECU LH

  • Stereo component equalizer assembly

  • Rear multiplex network door ECU RH

  • No. 7 CAN junction terminal

  • No. 1 CAN junction connector

  • No. 21 CAN junction connector
*1: w/ Telematics Transceiver
*2: w/ Bus Buffer ECU

WIRING DIAGRAM

B006AEGE03

CAUTION / NOTICE / HINT

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

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 engine switch off and leave the vehicle for 1 minute or more without operating the key or any 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 engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

    Click here

  • Some parts must be initialized and set when replacing or removing and installing parts.

    Click here

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

    DTC check procedure: Turn the engine switch on (IG) and wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.

  • After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed as normal.

    Click here

  • The following malfunctions may occur if a radio receiver assembly from another vehicle is installed to this vehicle. Therefore, when replacing the radio receiver assembly, be sure to replace it with new one.


    • Communication malfunction DTC is output

    • Does not operate normally

Tech Tips


  • Before disconnecting related connectors for inspection, push in on each connector body to check that the connector is not loose or disconnected.

  • When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.

PROCEDURE


  1. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 1 CAN JUNCTION CONNECTOR)


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

    2. Disconnect the G119 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 Connected to
      G119-12 (CANH) - G20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Radio receiver assembly
      G119-1 (CANL) - G20-16 (BAT)
      G119-13 (CANH) - G20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Central gateway ECU (network gateway ECU)
      G119-2 (CANL) - G20-16 (BAT)
      G119-14 (CANH) - G20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 21 CAN junction connector
      G119-3 (CANL) - G20-16 (BAT)
      G119-15 (CANH) - G20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Bus buffer ECU*1
      G119-4 (CANL) - G20-16 (BAT)
      G119-16 (CANH) - G20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Telematics transceiver*2
      G119-5 (CANL) - G20-16 (BAT)
      *1: w/ Bus Buffer ECU
      *2: w/ Telematics Transceiver
      Result
      Result Proceed to
      OK A
      NG (Central gateway ECU [network gateway ECU] CAN main wire) B
      NG (No. 21 CAN junction connector CAN main wire) C
      NG (Wire to ECU or sensor) D

    A

    REPLACE NO. 1 CAN JUNCTION CONNECTOR

    C

    CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 21 CAN JUNCTION CONNECTOR) Click here

    D

    GO TO STEP 4 Click here

    B

  2. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 1 CAN JUNCTION CONNECTOR)


    1. Reconnect the G119 No. 1 CAN junction connector.

    2. Disconnect the G66 central gateway ECU (network gateway ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G66-6 (CA3H) - G20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      G66-21 (CA3L) - G20-16 (BAT)
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) Click here

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 1 CAN JUNCTION CONNECTOR)

  3. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 21 CAN JUNCTION CONNECTOR)


    1. Reconnect the G119 No. 1 CAN junction connector.

    2. Disconnect the L131 No. 21 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      L131-1 (CANH) - G20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 1 CAN junction connector
      L131-7 (CANL) - G20-16 (BAT)
      L131-2 (CANH) - G20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Luggage closer motor assembly
      L131-8 (CANL) - G20-16 (BAT)
      L131-3 (CANH) - G20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Rear multiplex network door ECU LH
      L131-9 (CANL) - G20-16 (BAT)
      L131-4 (CANH) - G20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Stereo component equalizer assembly
      L131-10 (CANL) - G20-16 (BAT)
      L131-5 (CANH) - G20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 7 CAN junction terminal
      L131-11 (CANL) - G20-16 (BAT)
      L131-6 (CANH) - G20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Rear multiplex network door ECU RH
      L131-12 (CANL) - G20-16 (BAT)
      Result
      Result Proceed to
      OK A
      NG (No. 1 CAN junction connector CAN main wire) B
      NG (Wire to ECU or sensor) C

    A

    REPLACE NO. 21 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 21 CAN JUNCTION CONNECTOR - NO. 1 CAN JUNCTION CONNECTOR)

    C

  4. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (ECU, SENSOR)


    1. B006FRUC21
      *a

      Component with harness connected

      (Central Gateway ECU [Network Gateway ECU])

      Reconnect all wire harness connectors.

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

      Click here

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G66-6 (CA3H) - G20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      G66-21 (CA3L) - G20-16 (BAT)

      Tech Tips


      • If the resistance changes to 6 kΩ or higher when the connector is disconnected from the ECU or sensor, there may be a short in the ECU or sensor.

      • If the resistance does not become normal when the connector is disconnected from the ECU or sensor, check for a short to +B in the wire harness and repair or replace the wire harness or connector if necessary.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECU OR SENSOR

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR