CAN COMMUNICATION SYSTEM(w/ Central Gateway ECU) 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 no resistance exists 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
No resistance exists 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 line

  • Short to +B in CAN branch line

  • Central gateway ECU (network gateway ECU)

  • ECM

  • Combination meter assembly

  • Steering sensor (spiral cable with sensor sub-assembly)

  • Airbag sensor assembly

  • Power steering ECU with motor assembly

  • Brake actuator assembly

  • Main body ECU (multiplex network body ECU)

  • Headlight leveling ECU assembly

    (w/ Automatic Headlight Beam Level Control System)

  • Engine stop and start ECU

    (w/ Stop and Start System)

  • Clearance warning ECU assembly

    (w/ Simple Intelligent Parking Assist System)

  • Certification ECU (smart key ECU assembly)

    (w/ Entry and Start System)

  • Air conditioning amplifier assembly

    (w/ Air Conditioning System)

  • No. 1 CAN junction connector

  • No. 3 CAN junction connector

WIRING DIAGRAM

A01T8U6E03
A01TDJ4E04
A01TCM4E04
A01TD56E05

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 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 ignition 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 ignition switch to ON and wait at least 31 seconds, and then drive the vehicle at a speed of 20 km/h (12 mph) or more for 303 seconds 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.

    Click here

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 VEHICLE TYPE


    1. Check vehicle type.

      Result
      Result Proceed to
      for LHD A
      for RHD B

    B

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

    A

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


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

    2. Disconnect the E57 No. 3 CAN junction connector.

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

      A01TCPYC40
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 3 CAN Junction Connector)

      		 *b to Airbag Sensor Assembly
      *c to Air Conditioning Amplifier Assembly *d to Combination Meter Assembly
      *e to No. 1 CAN Junction Connector *f

      to Certification ECU (Smart Key ECU Assembly)

      (w/ Entry and Start System)
      *g

      to Clearance Warning ECU Assembly

      (w/ Simple Intelligent Parking Assist System)

      		 *h

      to Engine Stop and Start ECU

      (w/ Stop and Start System)
      *i to Power Steering ECU with Motor Assembly *j to Steering Sensor (Spiral Cable with Sensor Sub-assembly)
      *k to Central Gateway ECU (Network Gateway ECU) - -
      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      E57-1 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Airbag sensor assembly
      E57-12 (CANL) - E11-16 (BAT)
      E57-2 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Air conditioning amplifier assembly
      E57-13 (CANL) - E11-16 (BAT)
      E57-4 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Combination meter assembly
      E57-15 (CANL) - E11-16 (BAT)
      E57-5 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 1 CAN junction connector
      E57-16 (CANL) - E11-16 (BAT)
      E57-6 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Certification ECU (smart key ECU assembly)*1
      E57-17 (CANL) - E11-16 (BAT)
      E57-7 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Clearance warning ECU assembly*2
      E57-18 (CANL) - E11-16 (BAT)
      E57-8 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Engine stop and start ECU*3
      E57-19 (CANL) - E11-16 (BAT)
      E57-9 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Power steering ECU with motor assembly
      E57-20 (CANL) - E11-16 (BAT)
      E57-10 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Steering sensor (spiral cable with sensor sub-assembly)
      E57-21 (CANL) - E11-16 (BAT)
      E57-11 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Central gateway ECU (network gateway ECU)
      E57-22 (CANL) - E11-16 (BAT)

      • *1: w/ Entry and Start System

      • *2: w/ Simple Intelligent Parking Assist System

      • *3: w/ Stop and Start System

      Result
      Result Proceed to
      OK A
      NG (Line to No. 1 CAN junction connector) B
      NG (Line to ECU or sensor) C

    A

    REPLACE NO. 3 CAN JUNCTION CONNECTOR

    C

    GO TO STEP 6 Click here

    B

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


    1. Disconnect the A32 No. 1 CAN junction connector.

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

      A01TCPYC42
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 1 CAN Junction Connector)

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

      to Headlight Leveling ECU Assembly

      (w/ Automatic Headlight Beam Level Control System)
      *e to Brake Actuator Assembly *f to ECM
      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      A32-1 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 3 CAN junction connector
      A32-12 (CANL) - E11-16 (BAT)
      A32-3 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Main body ECU (multiplex network body ECU)
      A32-14 (CANL) - E11-16 (BAT)
      A32-4 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Headlight leveling ECU assembly*
      A32-15 (CANL) - E11-16 (BAT)
      A32-5 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Brake actuator assembly
      A32-16 (CANL) - E11-16 (BAT)
      A32-6 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher ECM
      A32-17 (CANL) - E11-16 (BAT)

      • *: w/ Automatic Headlight Beam Level Control System

      Result
      Result Proceed to
      OK A
      NG (Line to No. 3 CAN junction connector) B
      NG (Line to ECU or sensor) C

    A

    REPLACE NO. 1 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 1 CAN JUNCTION CONNECTOR - NO. 3 CAN JUNCTION CONNECTOR)

    C

    GO TO STEP 6 Click here

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


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

    2. Disconnect the E57 No. 3 CAN junction connector.

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

      A01TCPYC41
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 3 CAN Junction Connector)

      		 *b to Airbag Sensor Assembly
      *c

      to Air Conditioning Amplifier Assembly

      (w/ Air Conditioning System)

      		 *d to Combination Meter Assembly
      *e to No. 1 CAN Junction Connector *f to Power Steering ECU with Motor Assembly
      *g to Steering Sensor (Spiral Cable with Sensor Sub-assembly) *h to Central Gateway ECU (Network Gateway ECU)
      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      E57-1 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Airbag sensor assembly
      E57-12 (CANL) - E11-16 (BAT)
      E57-2 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Air conditioning amplifier assembly*
      E57-13 (CANL) - E11-16 (BAT)
      E57-4 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Combination meter assembly
      E57-15 (CANL) - E11-16 (BAT)
      E57-5 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 1 CAN junction connector
      E57-16 (CANL) - E11-16 (BAT)
      E57-9 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Power steering ECU with motor assembly
      E57-20 (CANL) - E11-16 (BAT)
      E57-10 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Steering sensor (spiral cable with sensor sub-assembly)
      E57-21 (CANL) - E11-16 (BAT)
      E57-11 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Central gateway ECU (network gateway ECU)
      E57-22 (CANL) - E11-16 (BAT)

      • *: w/ Air Conditioning System

      Result
      Result Proceed to
      OK A
      NG (Line to No. 1 CAN junction connector) B
      NG (Line to ECU or sensor) C

    A

    REPLACE NO. 3 CAN JUNCTION CONNECTOR

    C

    CHECK FOR SHORT TO +B IN CAN BUS LINE (ECU OR SENSOR) Click here

    B

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


    1. Disconnect the A32 No. 1 CAN junction connector.

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

      A01TCPYC47
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 1 CAN Junction Connector)

      		 *b to No. 3 CAN Junction Connector
      *c

      to Engine Stop and Start ECU

      (w/ Stop and Start System)

      		 *d to Main Body ECU (Multiplex Network Body ECU)
      *e to Brake Actuator Assembly *f to ECM
      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      A32-1 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher No. 3 CAN junction connector
      A32-12 (CANL) - E11-16 (BAT)
      A32-2 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Engine stop and start ECU*
      A32-13 (CANL) - E11-16 (BAT)
      A32-3 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Main body ECU (multiplex network body ECU)
      A32-14 (CANL) - E11-16 (BAT)
      A32-5 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Brake actuator assembly
      A32-16 (CANL) - E11-16 (BAT)
      A32-6 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher ECM
      A32-17 (CANL) - E11-16 (BAT)

      • *: w/ Stop and Start System

      Result
      Result Proceed to
      OK A
      NG (Line to No. 3 CAN junction connector) B
      NG (Line to ECU or sensor) C

    A

    REPLACE NO. 1 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 1 CAN JUNCTION CONNECTOR - NO. 3 CAN JUNCTION CONNECTOR)

    C

  6. 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.

      A01TBQWC23
      *1 DLC3 - -
      *a

      Component with harness connected

      (Central Gateway ECU (Network Gateway ECU))

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      E139-18 (CA4H) - E11-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      E139-17 (CA4L) - E11-16 (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