CAN COMMUNICATION SYSTEM(for RHD) Check Bus 2 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 18 (CA4H) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3, or terminal 17 (CA4L) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3.

Symptom Trouble Area
There is no resistance between terminal 18 (CA4H) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3, or terminal 17 (CA4L) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3.

  • Short to +B in CAN main bus lines

  • Short to +B in CAN branch lines

  • Central gateway ECU (network gateway ECU)

  • Combination meter assembly

  • ECM

  • Power steering ECU assembly

  • Main body ECU (multiplex network body ECU)

  • Steering sensor

  • Airbag ECU assembly

  • Skid control ECU (brake actuator assembly)

  • Air conditioning amplifier assembly

  • Certification ECU (smart key ECU assembly)

  • Headlight ECU sub-assembly LH

  • Engine stop and start ECU

  • Parking brake ECU assembly

  • No. 4 CAN junction connector

  • No. 3 CAN junction connector

WIRING DIAGRAM

B006PU6E01
B006NYQE01

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

  • 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

  • Before replacing the main body ECU (multiplex network body ECU), ECM or certification ECU (smart key ECU assembly), refer to Service Bulletin.

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 LINE (NO. 4 CAN JUNCTION CONNECTOR)


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

    2. Disconnect the G98 No. 4 CAN junction connector.

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

      B006NCOC16
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 4 CAN Junction Connector)

      		 *b to No. 3 CAN Junction Connector
      *c to Combination Meter Assembly *d to Certification ECU (Smart Key ECU Assembly)
      *e to Power Steering ECU Assembly *f to Steering Sensor
      *g to Engine Stop and Start ECU *h to Central Gateway ECU (Network Gateway ECU)
      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      G98-1 (CANH) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 3 CAN junction connector
      G98-11 (CANL) - G9-16 (BAT)
      G98-2 (CANH) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Combination meter assembly
      G98-12 (CANL) - G9-16 (BAT)
      G98-3 (CANH) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Certification ECU (smart key ECU assembly)
      G98-13 (CANL) - G9-16 (BAT)
      G98-5 (CANH) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Power steering ECU assembly
      G98-15 (CANL) - G9-16 (BAT)
      G98-7 (CANH) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Steering sensor
      G98-17 (CANL) - G9-16 (BAT)
      G98-8 (CANH) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Engine stop and start ECU
      G98-18 (CANL) - G9-16 (BAT)
      G98-10 (CANH) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Central gateway ECU (network gateway ECU)
      G98-20 (CANL) - G9-16 (BAT)
      Result
      Result Proceed to
      OK A
      NG (Line to central gateway ECU (network gateway ECU)) B
      NG (Line to No. 3 CAN junction connector) C
      NG (Line to ECU or sensor) D

    A

    REPLACE NO. 4 CAN JUNCTION CONNECTOR

    C

    CHECK FOR SHORT TO +B IN CAN BUS LINE (NO. 3 CAN JUNCTION CONNECTOR) Click here

    D

    GO TO STEP 4 Click here

    B

  2. CHECK FOR SHORT TO +B IN CAN BUS LINE (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))


    1. Disconnect the G116 central gateway ECU (network gateway ECU) connector.

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

      B006O33C16
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to Central Gateway ECU (Network Gateway ECU))

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      G116-18 (CA4H) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      G116-17 (CA4L) - G9-16 (BAT)
      Result
      Result
      OK
      NG

    OK

    REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) Click here

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) - NO. 4 CAN JUNCTION CONNECTOR)

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


    1. Disconnect the G97 No. 3 CAN junction connector.

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

      B006NCOC17
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 3 CAN Junction Connector)

      		 *b to ECM
      *c to Main Body ECU (Multiplex Network Body ECU) *d to Airbag ECU Assembly
      *e to Parking Brake ECU Assembly *f to Skid Control ECU (Brake Actuator Assembly)
      *g to No. 4 CAN Junction Connector *h to Headlight ECU Sub-assembly LH
      *i to Air Conditioning Amplifier Assembly - -
      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      G97-3 (CANH) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher ECM
      G97-13 (CANL) - G9-16 (BAT)
      G97-4 (CANH) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Main body ECU (multiplex network body ECU)
      G97-14 (CANL) - G9-16 (BAT)
      G97-5 (CANH) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Airbag ECU assembly
      G97-15 (CANL) - G9-16 (BAT)
      G97-6 (CANH) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Parking brake ECU assembly
      G97-16 (CANL) - G9-16 (BAT)
      G97-7 (CANH) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Skid control ECU (brake actuator assembly)
      G97-17 (CANL) - G9-16 (BAT)
      G97-8 (CANH) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 4 CAN junction connector
      G97-18 (CANL) - G9-16 (BAT)
      G97-9 (CANH) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Headlight ECU sub-assembly LH
      G97-19 (CANL) - G9-16 (BAT)
      G97-10 (CANH) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Air conditioning amplifier assembly
      G97-20 (CANL) - G9-16 (BAT)
      Result
      Result Proceed to
      OK A
      NG (Line to No. 4 CAN junction connector) B
      NG (Line to ECU or sensor) C

    A

    REPLACE NO. 3 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 3 CAN JUNCTION CONNECTOR - NO. 4 CAN JUNCTION CONNECTOR)

    C

  4. CHECK FOR SHORT TO +B IN CAN BUS LINE (ECU OR SENSOR)


    1. Reconnect all wire harness connectors.

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

      Click here

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

      B006M71C36
      *1 DLC3 - -
      *a

      Component with harness connected

      (Central Gateway ECU (Network Gateway ECU))

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      G116-18 (CA4H) - G9-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      G116-17 (CA4L) - G9-16 (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
      Result
      OK
      NG

    OK

    REPLACE ECU OR SENSOR

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR