CAN COMMUNICATION SYSTEM Short to GND in CAN Bus Line

DESCRIPTION

A short to GND is suspected in the CAN bus line when there is continuity between terminals 4 (CG) and 6 (CANH) or terminals 4 (CG) and 14 (CANL) of the DLC3.

Symptom Trouble Area
There is continuity between terminals 4 (CG) and 6 (CANH) or terminals 4 (CG) and 14 (CANL) of the DLC3.

  • Short to GND in CAN bus line

  • ECM

  • Air conditioning amplifier

  • CAN J/C

WIRING DIAGRAM

A01BDLME01

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK CAN BUS LINE SHORT TO GND (DLC3 SUB BUS LINE)


    1. A01BFF5E05

      Disconnect the DLC3 sub bus line connector (H5) from the CAN J/C.

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.

    2. A01BI1KE23

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

      Standard resistance
      Tester connection Condition Specified value
      H23-4 (CG) - H23-6 (CANH) IG switch OFF 1 MΩ or higher
      H23-4 (CG) - H23-14 (CANL) IG switch OFF 1 MΩ or higher

      Tech Tips


      • NG-A: Resistance between terminals CG and CANH is less than 1 MΩ.

      • NG-B: Resistance between terminals CG and CANL is less than 1 MΩ.


    NG-A

    REPAIR OR REPLACE DLC3 SUB BUS LINE OR CONNECTOR (CAN-H)

    NG-B

    REPAIR OR REPLACE DLC3 SUB BUS LINE OR CONNECTOR (CAN-L)

    OK

  2. CONNECT CONNECTOR


    1. Reconnect the DLC3 sub bus line connector (H5) to the CAN J/C.


    NEXT

  3. CHECK CAN BUS LINE SHORT TO GND (AIR CONDITIONING AMPLIFIER SUB BUS LINE)


    1. A01BFF5E06

      Disconnect the air conditioning amplifier sub bus line connector (H3) from the CAN J/C.

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.

    2. A01BI1KE23

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

      Standard resistance
      Tester connection Condition Specified value
      H23-4 (CG) - H23-6 (CANH) IG switch OFF 3 kΩ or higher
      H23-4 (CG) - H23-14 (CANL) IG switch OFF 3 kΩ or higher

    NG

    CONNECTOR CONNECT Click here

    OK

  4. CHECK CAN BUS LINE SHORT TO GND (AIR CONDITIONING AMPLIFIER SUB BUS LINE)


    1. Disconnect the air conditioning amplifier connector (H18).

    2. A01BHX5E06

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

      Standard resistance
      Tester connection Condition Specified value

      H18-10 (CANH) -

      H18-29 (GND)

      		 IG switch OFF 1 MΩ or higher

      H18-11 (CANL) -

      H18-29 (GND)

      		 IG switch OFF 1 MΩ or higher

      Tech Tips


      • NG-A: Resistance between terminals GND and CANH is less than 1 MΩ.

      • NG-B: Resistance between terminals GND and CANL is less than 1 MΩ.

      • Check the air conditioning amplifier sub bus line connector (H3) while disconnected from the CAN J/C.


    NG-A

    REPAIR OR REPLACE AIR CONDITIONING AMPLIFIER SUB BUS LINE OR CONNECTOR (CAN-H)

    NG-B

    REPAIR OR REPLACE AIR CONDITIONING AMPLIFIER SUB BUS LINE OR CONNECTOR (CAN-L)

    OK

    REPLACE AIR CONDITIONING AMPLIFIER

  5. CONNECTOR CONNECT


    1. Reconnect the air conditioning amplifier sub bus line connector (H3) to the CAN J/C.


    NEXT

  6. CHECK CAN BUS LINE SHORT TO GND (ECM MAIN BUS LINE)


    1. A01BFF5E04

      Disconnect the ECM main bus line connector (H4) from the CAN J/C.

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.

    2. A01BI1KE23

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

      Standard resistance
      Tester connection Condition Specified value
      H23-4 (CG) - H23-6 (CANH) IG switch OFF 3 kΩ or higher
      H23-4 (CG) - H23-14 (CANL) IG switch OFF 3 kΩ or higher

    NG

    REPLACE CAN J/C

    OK

  7. CHECK CAN BUS LINE SHORT TO GND (ECM MAIN BUS LINE)


    1. Disconnect the ECM connectors (B7) and (D1). (for 2TR-FE, 2KD-FTV)

      A01BGJWE01

    2. Disconnect the ECM connectors (B47) and (D70). (for 1KD-FTV)

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

      Standard resistance
      for 2TR-FE
      Tester Connection Condition Specified value
      B7-33 (CANH) - D1-7 (E01) IG switch OFF 1 MΩ or higher
      B7-34 (CANL) - D1-7 (E01) IG switch OFF 1 MΩ or higher
      for 1KD-FTV
      Tester Connection Condition Specified value
      B47-35 (CANH) - D70-12 (E01) IG switch OFF 1 MΩ or higher
      B47-36 (CANL) - D70-12 (E01) IG switch OFF 1 MΩ or higher
      for 2KD-FTV
      Tester Connection Condition Specified value
      B7-24 (CANH) - D1-7 (E01) IG switch OFF 1 MΩ or higher
      B7-23 (CANL) - D1-7 (E01) IG switch OFF 1 MΩ or higher

      Tech Tips


      • NG-A: Resistance between terminals E01 and CANH is less than 1 MΩ.

      • NG-B: Resistance between terminals E01 and CANL is less than 1 MΩ.

      • Check the ECM main bus line connector (H4) while disconnected from the CAN J/C.


    NG-A

    REPAIR OR REPLACE ECM MAIN BUS LINE OR CONNECTOR (CAN-H)

    NG-B

    REPAIR OR REPLACE ECM MAIN BUS LINE OR CONNECTOR (CAN-L)

    OK

    REPLACE ECM