CAN COMMUNICATION SYSTEM Check Bus 3 Line for Short to GND

DESCRIPTION

There may be a short circuit between one of the CAN bus lines and GND when there is no resistance between terminal 6 (CA3H) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3, or terminal 21 (CA3L) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3.

Symptom Trouble Area
No resistance exists between terminal 6 (CA3H) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3, or terminal 21 (CA3L) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3.

  • Short to ground in CAN main bus line

  • Short to ground in CAN branch line

  • Central gateway ECU (network gateway ECU)

  • Radio Receiver Assembly

    (w/ Navigation System or Audio and Visual System)

  • Telematics transceiver

    (w/ Telematics Transceiver)

  • No. 7 CAN junction connector

    (for RHD)

  • No. 8 CAN junction connector

    (for LHD)

WIRING DIAGRAM

B003YMRE01
B003Y3KE01

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 or any 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), wait at least 31 seconds, and then drive the vehicle at a speed of 20 km/h (12 mph) or more for 11 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 as normal.

    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 GND IN CAN BUS LINE (NO. 7 CAN JUNCTION CONNECTOR) Click here

    A

  2. CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 8 CAN JUNCTION CONNECTOR)


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

    2. Disconnect the K116 No. 8 CAN junction connector.

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

      B003XQZC86
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 8 CAN Junction Connector)

      		 *b to Central Gateway ECU (Network Gateway ECU)
      *c

      to Telematics Transceiver

      (w/ Telematics Transceiver)

      		 *d

      to Radio Receiver Assembly

      (w/ Navigation System or Audio and Visual System)
      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      K116-7 (CANH) - K9-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Central gateway ECU (network gateway ECU)
      K116-18 (CANL) - K9-4 (CG)
      K116-8 (CANH) - K9-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Telematics transceiver*1
      K116-19 (CANL) - K9-4 (CG)
      K116-9 (CANH) - K9-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Radio receiver assembly*2
      K116-20 (CANL) - K9-4 (CG)
      K116-11 (CANH) - K9-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Central gateway ECU (network gateway ECU)
      K116-22 (CANL) - K9-4 (CG)

      • *1: w/ Telematics Transceiver

      • *2: w/ Navigation System or Audio and Visual System

      Result
      Result Proceed to
      OK A
      NG (Line to central gateway ECU (network gateway ECU)) B
      NG (Line to ECU or sensor) C

    A

    REPLACE NO. 8 CAN JUNCTION CONNECTOR

    C

    GO TO STEP 6 Click here

    B

  3. CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 8 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))


    1. Disconnect the K146 central gateway ECU (network gateway ECU) connector.

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

      B003XQZC87
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 8 CAN Junction Connector)

      		 *b to Central Gateway ECU (Network Gateway ECU)
      Standard Resistance
      Tester Connection Condition Specified Condition
      K116-7 (CANH) - K9-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      K116-18 (CANL) - K9-4 (CG)
      K116-11 (CANH) - K9-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      K116-22 (CANL) - K9-4 (CG)
      Result
      Result
      OK
      NG

    OK

    REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) Click here

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))

  4. CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 7 CAN JUNCTION CONNECTOR)


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

    2. Disconnect the K115 No. 7 CAN junction connector.

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

      B003XQZC88
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 7 CAN Junction Connector)

      		 *b to Central Gateway ECU (Network Gateway ECU)
      *c

      to Radio Receiver Assembly

      (w/ Navigation System or Audio and Visual System)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      K115-7 (CANH) - K9-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Central gateway ECU (network gateway ECU)
      K115-18 (CANL) - K9-4 (CG)
      K115-9 (CANH) - K9-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Radio receiver assembly*
      K115-20 (CANL) - K9-4 (CG)
      K115-11 (CANH) - K9-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Central gateway ECU (network gateway ECU)
      K115-22 (CANL) - K9-4 (CG)

      • *: w/ Navigation System or Audio and Visual System

      Result
      Result Proceed to
      OK A
      NG (Line to central gateway ECU (network gateway ECU)) B
      NG (Line to ECU or sensor) C

    A

    REPLACE NO. 7 CAN JUNCTION CONNECTOR

    C

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

    B

  5. CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 7 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))


    1. Disconnect the K146 central gateway ECU (network gateway ECU) connector.

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

      B003XQZC89
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 7 CAN Junction Connector)

      		 *b to Central Gateway ECU (Network Gateway ECU)
      Standard Resistance
      Tester Connection Condition Specified Condition
      K115-7 (CANH) - K9-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      K115-18 (CANL) - K9-4 (CG)
      K115-11 (CANH) - K9-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      K115-22 (CANL) - K9-4 (CG)
      Result
      Result
      OK
      NG

    OK

    REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) Click here

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 7 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))

  6. CHECK FOR SHORT TO GND 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 GND is connected.

      Click here

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

      B003Y57C77
      *1 DLC3 - -
      *a

      Component with harness connected

      (Central Gateway ECU (Network Gateway ECU))

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      K146-6 (CA3H) - K9-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      K146-21 (CA3L) - K9-4 (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.

      • If the resistance does not become normal when the connector is disconnected from the ECU or sensor, check for a short to ground 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